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the outside world and HUD symbology. The left and right DDIs, MPCD and the AMPCD contain

pushbuttons for display selection and selection of various equipment operating modes. The UFCD is

an active matrix liquid crystal display with an infrared (IR) touchscreen for operator inputs. Refer to

Part VII for the operation of each component.

2.19.4.1 CRS Set Switch. The course set switch, located on the main instrument panel on the video

record panel, manually sets the desired course on the HSI display.

2.19.4.2 HDG/TK Set Switch. The heading/ground track set switch located on the main instrument

panel on the video record panel, manually sets the heading marker on the desired heading/ground track

on the HSI display.

2.19.4.3 DDIs. The left and right DDI (LDDI/RDDI) are physically and functionally interchange-

able, giving the ability to display desired information on either indicator. The left indicator is used

primarily for stores status, built in test status, engine monitor, caution, and advisory displays. The

right indicator is normally used for radar and weapon video displays. The DDIs have full color

capability in all display modes and are NVG compatible.

NOTE

It is possible that a transient condition may cause the displays to

blank or provide an erroneous display on the left or right DDI, or

HUD. The problem may be cleared by manually cycling the power to

the left or right DDI.

2.19.4.3.1 Brightness Knob. Placing this rotary knob to OFF prevents the DDI from operating.

When turned on, rotating the knob clockwise increases display brightness, while rotating the knob

counterclockwise decreases display brightness.

2.19.4.3.2 GAIN Control. This three-position rocker switch affects the existing gray-scale, shifting

the background brightness up or down, with no impact on displayed symbology. The center position is

off, while the up arrow increases background brightness and the down arrow decreases background

brightness. The up and down arrows have momentary and scroll functionality, depending on how long

they are held. Current values are temporarily displayed when switches are pressed.

2.19.4.3.3 CONT Control. This three-position rocker switch varies the contrast between symbology

and the dark background on any level of brightness. When the contrast rocker is pressed, a graphical

and numeric representation of the current setting is momentarily displayed on the DDI.

2.19.4.3.4 DDI Pushbuttons. There are 20 pushbuttons on each DDI which are used to select the

function and the mode for proper indicator display.

2.19.4.3.5 Menu Formats. There are three MENU formats (figure 2-48); airborne electronic attack

(AEA), tactical (TAC), and support (SUPT), through which display selections can be made. The three

menu formats can appear on either the DDI, the UFCD, MPCD or AMPCD.

The MENU pushbutton cycles through the airborne electronic attack (AEA), tactical (TAC), and

support (SUPT) menus in the following order: AEA - TAC - SUPT. The current time of day, consisting

of two minute digits and two second digits appear below AEA/TAC/SUPT MENU legend (cold start

default). Time of day is also turned on/off with the TISM option on the Engine Format.

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The AEA MENU provides access to the following formats: Jammers (JMRS), Emitter Page

(EPAGE), SATCOM (SAT), Mission Planning (MPLAN), Frequency/Azimuth (FR/AZ), Communi-

cations Countermeasures Set (CCS), Tactical Situation Display (TSD), and HARM Handoff format,

(HHO DSPLY).

The TAC MENU allows selection of the following formats: AZ/EL, HUD, RDR ATTK, STORES,

HARM, SA, IMAGE, CAS, EW, and TGT DATA.

The SUPT MENU allows selection of the following formats: ADI, HSI, HMD, NETS, GPS, MIDS,

ROE/IFF PROG, BIT, CTT, MUMI, CHKLST, ENG, FCS, UFC BU, FPAS, and FUEL.

Some of the options on the MENU formats are conditional and are not always displayed. LST, and

CAM are listed only if the equipment is communicating with the mission computer. HARM DSPLY

is displayed when HARM is on board and CLC communicating. A/G missile display (WEDL DSPLY,

MAV DSPLY, etc.) is displayed when the MC has determined from the armament control processor set

that a weapon station has been selected which contains one of these weapons.

If either mission computer is off or failed (MC Backup Mode), the options available on the displays

are the same regardless of which computer is failed. If MC1 is failed or not communicating, the left

DDIs in both cockpits will either flash STANDBY or have a green square present in the middle of the

displays. If MC2 is failed or not communicating with the display, the right DDIs in both cockpits will

either flash STANDBY or have a green square present in the middle of the displays. The AMPCD will

not be capable of displaying format symbology or video. The following options are available in MC

Backup mode: HUD, EW, MIDS, MUMI, ENG, UFC BU, FUEL, ADI, and HSI. If A/A master mode

is selected, the RDR ATTK, SA, and AZ/EL formats are available as well. No A/G displays are

supported in MC Backup mode. If both mission computers are off or failed, a backup HUD format

(driven by the SDC) is displayed on the UFCD and MPCD in the front cockpit.

2.19.4.3.6 Electronic Attitude Display Indicator (EADI). The electronic attitude display indicator is

available for display on the left or right DDI as an alternative to the attitude display on the HUD

(figure 2-49). The EADI display is selected by selecting the ADI option on the SUPT MENU. The pitch

ladder is displayed in 10° increments. A small circle is displayed on the ball to represent the zenith and

a circle with an inscribed cross is displayed to represent the nadir. A turn indicator which displays FCS

yaw rate is provided below the ball. A standard rate turn (3°/second) is indicated when the lower box

is displaced so that it is under one of the end boxes.

Selecting the INS or STBY options at the bottom of the display determines the source of attitude

information used to generate the display. Upon power-up with WonW, the EADI attitude initializes to

STBY (STBY boxed), thus using the standby attitude reference indicator for attitude source

information. Selecting the INS option (INS boxed) uses attitude information provided by the INS.

Selection of INS or STBY on the EADI does not change the source of attitude data for the HUD.

Airspeed and altitude are displayed in boxes at the top left and right. Altitude source is displayed

to the right of the altitude box and the vertical velocity is displayed above the altitude box. When ILS

is selected the deviation needles are displayed in reference to the waterline symbol. The ILS needles

are yellow when COLOR is selected on the Attack display.

2.19.4.3.7 Shaped Attitude Display Indicator. When the ADI option is selected on the SUPT menu,

a shaped attitude display indicator is available on the MPCD, UFCD, or DDI and AMPCD. The pitch

ladder is displayed in 10° increments, with ±30° in pitch being displayed when the gear is up. With the

gear down, the pitch ladder is displayed in 5° increments with ±15° in pitch being displayed. A turn

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Figure 2-49. Electronic Attitude Display Indicator

indicator is provided below the ball. A standard rate turn (3°/second) is indicated when the lower box

is displaced so that it is under one of the end boxes.

On the MPCD and AMPCD, the shaped ADI is black above the horizon to represent sky, and green

below the horizon to represent the ground. On the UFCD, the shaped ADI is unshaded above the

horizon (sky) and shaded green below the horizon (ground).

Selecting the INS or STBY options at the bottom of the display determines the source of attitude

information used to generate the display. Upon power-up with WonW, the ADI attitude initializes to

STBY (STBY boxed), thus using the standby attitude reference indicator for attitude source

information. Selecting the INS option (INS boxed) uses attitude information provided by the INS.

Selection of INS or STBY on the ADI does not change the source of attitude data for the HUD.

Airspeed and altitude are displayed in boxes at the top, altitude source is displayed to the right of

the altitude box and vertical velocity is displayed above the altitude box. When ILS is selected the

deviation needles are displayed in reference to the waterline symbol. The ILS needles are yellow when

COLOR is selected on the attack display.

2.19.4.4 Multipurpose Color Display (MPCD). The MPCD is an NVG compatible digital display

capable of providing any MENU selectable format except the video on the A/G radar display (figure

2-51). The MPCD drives itself using information received on the MUX.

The BRT knob controls the overall video and symbology brightness and also acts as the power

control for the MPCD and UFCD; a detented OFF position at the extreme counterclockwise position.

The CONT knob adjusts the video contrast of the MPCD display. The day/night mode is controlled

by the day/night/NVG switch on the interior lights panel.

2.19.4.4.1 Standby Indication. A flashing STANDBY indication is provided in the center of the

display on initial power-up and when there is invalid mux communication with the MC. If the

STANDBY condition persists for a few seconds, cycling power to the MPCD may return the MPCD

and UFCD to normal operation.

2.19.4.4.2 Brightness and Contrast Controls. The brightness control is used to adjust the overall

brightness of the MPCD display surface, allowing symbology and video to be adjusted. The full

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counterclockwise position of the brightness control knob shuts off power to both the MPCD and the

UFCD. Selecting ON powers both the MPCD and the UFCD.

The contrast control is used to adjust video contrast.

2.19.4.4.3 Symbology Rocker Switch. The symbology (SYM) brightness rocker switch is used to

adjust the brightness of the symbology without affecting the brightness of the MPCD video.

Symbology change feedback in provided in the left center of the display by a digit from 0 to 9. This

feedback is provided while the rocker switch is pressed and for 5 seconds after the rocker switch is

released.

2.19.4.4.4 DDI Formats on MPCD. Every display format is available on the L or R DDI. A/G radar

symbology and monochrome video is available on the MPCD. A/G video is not available.

2.19.4.4.5

MPCD Formats. If two different formats are requesting MAP video underlay, only one

displays the video underlay; the other provides only symbology. MAP video display priority is

determined by two things: 1) which display surface is requesting the MAP underlay and 2) which

format is requesting the MAP underlay. Highest display surface priority is given to the MPCD followed

by the DDIs. The SA format is given the highest priority, followed by the HSI format, for formats

requesting the MAP underlay. Once the MAP is displayed for any format, (SA, HSI), any display

surface with that same format selected will also have the MAP underlay displayed. The MAP underlay

is only supported on the SA or HSI formats.

2.19.4.4.6 AMPCD. The AMPCD has a full color Active Matrix Liquid Crystal Display surface and

30 pushbuttons used for operator inputs. Only 20 buttons are functional, and they duplicate the

MPCD/DDI menu layouts. The top row outboard buttons and top four buttons on each side are not

used. The brightness control switch adjusts the video brightness. The full counterclockwise position, a

detented OFF position, removes power from the AMPCD and the aft cockpit UFCD. Two rocker

switches provide Gain and Contrast control. A numeric value displayed near the switches is used to

adjust the gain and/or contrast to a desired level. Pushbuttons are backlit, controlled by the INST

PNL knob on the aft cockpit interior lights panel. The following formats and related sublevel formats

are available: AEA Menu, TAC Menu, SUPT Menu, HSI, EW, SA, and BIT. Figure 2-50 shows

symbology placement and map coverage for the AMPCD. See foldout section for aft cockpit

arrangement.

The AMPCD is connected directly to MC2. When MC2 is offline or during initialization, the

AMPCD does not show a format or process bezel inputs. A flashing STANDBY indication is provided

in the center of the AMPCD when MC2 is not communicating properly with the AMPCD. A standby

display pattern (approximately a one inch by one inch green square) is present when the Image

Transfer Bus (ITB) has lost symbology, video, or a combination, and the selected format is affected.

When interface between MC2 and AMPCD is lost, only symbology is displayed (via ITB). There is no

pushbutton feedback, video control, or BIT reporting when interface is degraded. The day/night mode

of the AMPCD (and rear UFCD) is set via the DAY/NITE/NVG switch on the forward cockpit interior

lights panel through MC2.

In the Situational Awareness (SA) format, the cursor (captains bars) may be slewed over the entire

AMPCD surface. Because this area is larger than the DDIs/MPCD, if another display is showing the

same format and the cursor on the AMPCD is slewed beyond the center area, the cursor on the

DDI/MPCD is limited. When this happens, the cursor on the DDI/MPCD displays flashes continu-

ously. When a SA format has DC priority assigned, the initial cursor position is determined by the

cockpit that initiates the slewing action.

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2.19.4.5 HSI Display Symbology. Basic HSI symbology such as the compass rose, ground track

pointer, lubber line (for magnetic heading), true airspeed readout, groundspeed readout, and aircraft

symbol are not described. These symbols are shown in figure 2-51.

Display format lines, just below the top row of pushbutton labels, indicate the formats being

displayed on the left, center, right and UFCD displays in both the cockpit (left side of HSI display) and

rear cockpit (right side of HSI display).

Radar target and GEOREF symbols are described in NTRP 3-22.2-EA-18G (EA-18G Classified

Manual). The following paragraphs describe unique navigation symbology. Refer to part VII for a

description of how these symbols are integrated with the navigation system:

1. Waypoint/OAP data. Data for the current steer to waypoint/OAP is displayed on the upper right

corner of the HSI. Waypoint/OAP data consists of bearing, range, and TTG (time-to-go) up to

8:59:59 based on distance and ground speed. When a waypoint/OAP or offset to the OAP is

designated (becomes a target), this data relates to the target. When a waypoint is a waypoint that

was transferred from the GPS, an ID code is displayed under the waypoint data.

2. TACAN data. TACAN data is displayed on the upper left corner of the HSI. TACAN data

consists of bearing, range (slant range), TTG (based on distance and present ground speed), and the

station identifier.

3. Waypoint/OAP symbology. Waypoint/OAP symbology consists of a waypoint/OAP symbol and a

bearing pointer and tail. The waypoint/OAP symbol indicates the position of the selected

waypoint/OAP relative to the aircraft symbol. The waypoint/OAP bearing pointer and tail are

displayed inside the compass rose and indicate bearing to the selected waypoint/OAP. Waypoint/

OAP symbology is displayed whether or not waypoint/OAP steering is selected. When the selected

waypoint/OAP is outside the HSI range scale, the waypoint/OAP symbol does not appear, but the

bearing pointer and tail appears. When a waypoint/OAP is designated, the waypoint/OAP symbol

and circle inside the pointer change to a diamond shape. The offset symbol appears when steering

is to an OAP. The offset symbol indicates the position of the offset relative to the OAP.

4. TACAN symbology. TACAN symbology consists of a TACAN symbol, and TACAN bearing

pointer and tail. The TACAN symbol indicates the position of the TACAN station relative to the

aircraft symbol. The TACAN bearing pointer and tail are located outside of the compass rose and

indicate bearing to the TACAN station. When the TACAN station is outside the HSI range scale, the

TACAN symbol does not appear but the bearing pointer and tail appear. When TACAN range

becomes invalid the TACAN symbol is not displayed.

5. Heading select/ground select marker and readout. The heading select/ground select marker is

maneuvered along the periphery of the compass rose using the HDG/TK switch. The digital readout

of the selected heading is located on the lower left corner of the HSI. The heading select/ground

select marker and digital readout are part of the heading select/ground track select mode of the

autopilot.

Course line arrow and readout. The course line arrow indicates the selected course to the

waypoint/OAP or TACAN station. The course is selected using the CRS switch. The digital readout

of the selected course is displayed on the lower right corner of the HSI. The course line arrow is not

displayed when TACAN range is invalid.

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6. TDC assignment symbol. The TDC assignment diamond is displayed on the upper right corner

of the HSI. This symbol indicates that the TDC is assigned to the HSI. The TDC assignment

diamond indicates control is assigned to both cockpits. Other symbols indicate cockpit (d) or rear

cockpit (e) TDC control and SLEW control. SLEW is done by actuating the sensor control switch

AFT while in the NAV or A/G master mode. The word SLEW is displayed in the TDC assignment

diamond position when the SLEW option is active.

7. Coupled steering symbology. CPL and the source of the steering information is displayed on

either side of the aircraft symbol in the center of the HSI display whenever the flight control system

is coupled in azimuth to a steering source. Steering source can be WYPT, TCN, or SEQ#. The couple

cue flashes for 10 seconds and is removed if the steering signal is lost or becomes invalid.

8. Sequential steering lines. The sequential steering lines are displayed when a sequence is entered

and when one of the sequence options (SEQ1, SEQ2, SEQ3, or SEQL) is boxed. The sequential

steering lines are available for display in all HSI modes and range scales. Sequential steering lines

are not displayed at power up with WonW and are removed when: magnetic heading is invalid,

aircraft position is invalid, or map slew is selected.

9. Time of day. Zulu time of day (ZTOD) or local time of day (LTOD) are displayed on the lower left

corner of the HSI. For aircraft that pass the FIRAMS real time clock power up BIT, ZTOD does not

need to be entered. For aircraft that do not pass the FIRAMS real time clock power up BIT, ZTOD

must be entered.

10. Groundspeed required. Groundspeed required appears below the current groundspeed readout.

Groundspeed required indicates the groundspeed required to a target based on entered ZTOD, time

on target (TOT), and the target.

11. Elapsed time (ET)/countdown (CD) time. ET and CD time are displayed on the lower right

corner of the HSI, however, only one of the timers can be displayed at a time. ET or CD timer must

be selected to be displayed. ET initializes to zero minutes and seconds and CD time initializes to six

minutes and zero seconds.

12. Aircraft heading. Aircraft heading is indicated on the compass rose. Aircraft heading and bearing

data can be selected as either magnetic or true. With true heading selected, the letter T appears

below the lubber line and the word TRUE appears below the selected scale readout. There is no

indication when magnetic heading is selected.

2.19.4.6 Head-Up Display (HUD). The HUD is on the center main instrument panel. The HUD is

used as the primary flight instrument, weapon status, and weapon delivery display for the aircraft

under all conditions. The HUD receives all symbology from MC1 or MC2. The HUD is electrically

interfaced with the UFCD. The HUD has NVG compatible raster display capability to allow it to

display NFLR video. The controls for the HUD are below the UFCD and are described in the following

paragraphs. See figure 2-52.

2.19.4.6.1 HUD Symbology Reject Switch. The HUD reject switch is located on the HUD control

panel on the center main instrument panel. This switch is used to control the amount of symbology

displayed on the HUD.

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Figure 2-52. HUD Controls

NORM Displays full HUD symbology.

REJ 1

Removes the Mach, g, and peak-g indications, the bank angle scale and pointer, the air-

speed and altitude boxes, energy caret (landing gear down), and the ground speed

required cue.

REJ 2

Removes REJ 1 symbology and the heading scale, current heading caret, command

heading marker, NAV/TCN range, and the ET, CD, LTOD or ZTOD timer.

2.19.4.6.2 HUD Symbology BRT Control Knob. This knob is used to turn on the HUD and then

varies the display intensity.

2.19.4.6.3 HUD Symbology Brightness Selector Switch. This is a two-position toggle switch with

positions of DAY and NIGHT. Placing the switch to DAY provides maximum symbol brightness in

conjunction with the HUD symbology brightness control. With the switch set to NIGHT, a reduced

symbol brightness is provided in conjunction with the HUD symbology brightness control.

2.19.4.6.4 Black Level Control Knob. The black level control knob, located on the HUD control

panel, adjusts the NFLR video plus or minus ½ a shade of gray per increment when rotated.

2.19.4.6.5 HUD Video Control Switch. The video control switch, located on the HUD control panel,

enables NFLR video display on the HUD with selectable polarity (white hot/black hot).

W/B Selects white hot/black hot polarity.

VID

Displays NFLR video in the HUD, if available.

OFF NFLR video off.

2.19.4.6.6 BAL Control Knob. The balance control, located on the HUD control panel, adjusts the

stroke brightness relative to the raster brightness. Rotating the switch from 12 o’clock towards the VID

position holds the brightness of the video (as set by the brightness control switch) and reduces the

brightness of the stroke symbology. The opposite is true when rotating the switch toward the SYM

position.

2.19.4.6.7 AOA Indexer Control Knob. This knob controls the brightness of the indexer lights.

2.19.4.6.8 ALT Selector Switch. The ALT selector switch, located on the HUD control panel, is used

to select the primary altitude source for display on the HUD and for use in the mission computer

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(weapon systems calculations).

BARO Selects barometric altitude.

RDR Selects radar altitude.

2.19.4.6.9 ATT Selector Switch. The ATT selector switch, located on the HUD control panel, is used

to select the primary attitude source used for display in the HUD and in MC and FCC computations.

INS

Functions identically to the AUTO position.

AUTO Selects filtered INS data as the primary attitude source. The INS automatically reverts

to gyro mode, using unfiltered data if its processor fails. The MC automatically selects

the standby attitude reference indicator for attitude information if the INS fails com-

pletely.

STBY Selects the standby attitude reference indicator. The FCCs no longer use INS data and

the HIAOA advisory is displayed.

2.19.4.6.10 HUD Symbology. The following paragraphs describe HUD symbology as related to basic

navigation, steering (direct, great circle, courseline, and ILS), navigation target designation, advisories

and landing, see figure 2-53. Refer to part VII for a description of how these symbols are integrated into

the navigation system. Also, refer to section VII for unique ACL data link symbology. Refer to NTRP

3-22.2-EA-18G (EA-18G Classified Manual), for symbology concerning the A/A and A/G master

modes, weapons, RWR and the data link vector mode.

1. Heading. The aircraft magnetic/true heading is indicated by the moving 30° heading scale. The

actual aircraft heading is directly above the caret/T symbol. The moving heading scale provides

trend information during turns. As the aircraft turns right, the scale moves from right to left.

Magnetic or true heading may be selected. Magnetic heading is indicated by a caret below the

heading scale. True heading selection is indicated by a T appearing below the current heading.

2. Airspeed. Calibrated airspeed from the FCC is provided in the box on the left side of the HUD.

The tops of the airspeed and altitude boxes are positioned at the aircraft waterline, which is 4° up

from the optical center of the HUD.

HUD airspeed should normally read less than 50 knots while sitting still

on the ground. A reading of more than 50 knots on the ground may

indicate an Air Data failure.

3. Altitude. The altitude presented in the box on the right side of the HUD may be either barometric

altitude or radar altitude depending on the setting of the altitude switch on the HUD control panel.

When the altitude switch is in the BARO position, barometric altitude is displayed. When the

altitude switch is in the RDR position, radar altitude is displayed and is identified by an R next to

the altitude. If the radar altitude is invalid, barometric altitude is displayed and a B next to the

altitude flashes to indicate that barometric altitude is being displayed rather than radar altitude.

The ten thousand and thousand digits are 150% size numbers. The hundred, ten, and unit digits are

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120% size numbers, except that below 1,000 feet they are 150% size.

4. Barometric setting. The barometric setting used by the air data function in the FCC is the value

set in the standby altimeter. When the barometer setting is changed on the standby altimeter, the

barometric setting is presented below the altitude on the HUD to provide a head-up baro-set

capability. The display remains for 5 seconds after the change is made. In addition, the baro-set

value is displayed and flashed for 5 seconds when the aircraft descends below 10,000 feet at an

airspeed less than 300 KCAS.

5. Angle of Attack. True angle of attack in degrees is displayed at the left center of the HUD. AOA

values displayed on the HUD are filtered and may slightly lag actual true AOA. Therefore, it may

be possible to trigger the AOA tone with the flaps in HALF or FULL slightly prior to seeing 14.0°

AOA in the HUD.

The HUD AOA is generally driven by the FCS using the AOA probes. However, around 42° AOA

(and -9°), the HUD reverts to an MC-computed AOA based on INS data and winds. The HUD AOA

flashes indicating that the displayed HUD AOA may be inaccurate because the INS computed winds

have not been updated in the past three minutes. Low AOA, small bank angles, and small rates are

required to update the wind.

The pitch trim AOA value is displayed next to the ATC HUD advisory location while trimming and

for two seconds after trimming with WoffW and flaps HALF or FULL. The value is displayed with

or without ATC engaged but is not displayed with autopilot engaged.

6. Mach number. The aircraft Mach number is displayed immediately below the angle of attack.

7. Aircraft g. Normal acceleration of the aircraft is displayed immediately below the Mach number.

8. Peak aircraft g. A peak positive g indication is displayed on the HUD below the normal g when

a threshold of 4.0 g is exceeded. The peak positive g display can be removed by cycling the clutter

reject switch to one of the reject positions.

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9. Bank angle scale. A bank angle scale and pointer are displayed at the bottom of the HUD for bank

angle reference up to 45°. At bank angles in excess of 47°, the bank angle scale pointer is limited at

45° and flashes.

10. Velocity vector. The velocity vector provides an outside world reference with regard to actual

aircraft flight path. The velocity vector represents the point towards which the aircraft is flying

(aircraft flight path). With a functioning INS, the velocity vector is driven by INS attitude and

velocities. If GPS data is valid, a ″hybrid″ GPS vertical velocity correction is used to correct errors

in the INS vertical velocity loop regardless of the INS mode switch position (CV, GND, NAV, or

IFA). If GPS data is not available for use in the hybrid correction, a VVEL advisory is displayed.

With a VVEL advisory displayed, sustained climbs and descents, such as

penetration from the marshal stack, can result in uncued (no cautions)

vertical velocity errors and a possible inaccurate velocity vector position.

Error magnitudes increase at slower airspeeds and lower altitudes. Errors

of up to 3° (actual flightpath 3° below the displayed velocity vector) have

been observed in the landing configuration. Three minutes of level flight

may be required to allow the INS to correct the vertical velocity errors.

NOTE

The VVEL advisory will be displayed if a GPS is not installed or if

masking prevents GPS positioning of a sufficient quality to ″aid″ the

INS vertical velocity loop.

The position of the velocity vector is limited to an 8° radius circle centered at the HUD optical

center. If the velocity vector reaches this limit during high angle of attack flight or large yaw and/or

drift angles, it flashes rapidly to indicate that it does not accurately indicate flight path (velocity vector

is HUD limited).

With GPS operating, if the INS velocity data becomes unreliable, the mission computer utilizes GPS

information. If INS velocity data becomes unreliable the mission computer utilizes FCC air data

function information and the last available wind data to compute the velocity vector and this degraded

velocity vector is indicated by a slow flashing of the symbol. In the NAV master mode, the velocity

vector may be caged to the vertical center line of the HUD by the cage/uncage switch on the throttle.

When it is caged, a ghost velocity vector is displayed at the true velocity vector position if that position

is more than 2° from the caged position. The flight path/pitch ladder and steering information are

referenced to the caged position. The ghost velocity vector flashes when limited. The flight path/pitch

ladder is referenced to the waterline symbol when the velocity vector is caged.

The velocity vector is automatically fixed at the horizon with WonW and ground speed less than 80

knots, and its status cannot be changed until WoffW. However, the velocity vector’s selected

caged/uncaged status does not change during touch-and-go landings if the ground speed remains above

80 knots.

11. Flight path/pitch ladder. The vertical flight path angle of the aircraft is indicated by the position

of the velocity vector on the flight path/pitch ladder. The horizon and flight path/pitch angle lines

represent the horizon and each 5° of angle between ±90°. Positive pitch lines are solid and are above

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the horizon line. Negative pitch lines are dashed and are below the horizon line. The outer segments

of the lines point toward the horizon. Each line is numbered and the numbers rotate with the lines

so that inverted flight can easily be determined. To aid in determining flight path angle when it is

changing rapidly, the pitch lines are angled toward the horizon at an angle half that of the flight path

angle. For example, the 50° pitch line is angled 25° toward the horizon. In level flight, the pitch lines

are not angled. The zenith is indicated by a circle and the nadir is indicated by a circle with an X

in it. Aircraft pitch angle can be determined by comparing the tops of the altitude and airspeed

boxes (which represent the aircraft waterline) with the pitch ladder when the wings are level, but the

flight path/pitch ladder normally rotates about the velocity vector and determination of pitch angle

may be difficult at high roll angles.

12. Vertical velocity readout. This value is displayed above the altitude box and indicates vertical

velocity in feet per minute. This is displayed in the NAV master mode only. Descent is indicated by

a minus sign.

13. HUD landing symbology. When any two landing gear are down, the Mach number, g, and peak

g are deleted and an AOA bracket, extended horizon bar, waterline symbol, and energy caret appear.

The center of the AOA bracket represents the optimum approach AOA. The bracket moves lower

with respect to the velocity vector as AOA increases and moves higher as AOA decreases. When the

energy state of the aircraft is in equilibrium, the energy caret points to the ″right wing″ of the

velocity vector and the aircraft neither accelerates or decelerates. With an energy deficit, the energy

caret moves lower with respect to the velocity vector and the aircraft decelerates; with excess energy,

the energy caret moves higher and the aircraft accelerates.

14. Waypoint/OAP, mark point, TACAN, or target data. Waypoint/OAP and mark data consists of

range (horizontal), and the steer-to point identifier (W, O, or M) and number located on the lower

right corner of the HUD. TACAN data consists of slant range and a Morse code identifier located

on the lower right corner of the HUD. When a steer-to point is designated, range remains displayed

and the steer-to point identifier changes to TGT.

15. Coupled steering symbology. While coupled steering is engaged CPL SEQ#, CPL WYPT, CPL

TCN, CPL BNK, CPL ASL, CPL HDG, or CPL P/R appears on the right side of the HUD display

above the navigation data.

16. ILS symbology. When ILS steering is selected, an azimuth deviation bar (localizer) and elevation

deviation bar (glideslope) appear on the HUD.

17. ZTOD, LTOD, ET, and CD time. The ZTOD, LTOD, ET, or CD time is displayed on the lower

left corner of the HUD. These timers are mutually exclusive. Only one timer is available for display

on the HUD at a time. When the FIRAMS real time clock power up BIT passes, ZTOD does not need

to be entered, but when the FIRAMS real time clock power up BIT does not pass, ZTOD must be

entered. ET initializes to zero minutes and seconds. CD initializes to six minutes and zero seconds.

18. Command heading marker. When waypoint/OAP or TACAN direct great circle steering is

selected, the command heading marker is displayed just below the heading scale.

19. Steering arrow and dots. When waypoint/OAP or TACAN course line steering is selected, the

steering arrow and dots appear on the HUD.

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20. Required ground speed cue. When steering is engaged to the target in a sequence, the required

ground speed cue appears under the airspeed box.

21. Target designation symbology. When a target is designated, a target designation symbol

(diamond) appears below the heading scale indicating target heading. Another target designation

symbol (diamond) appears indicating the target line of sight (LOS).

2.19.4.6.11 HUD Symbology Degrades. The avionics suite has built in redundancy with two mission

computers for data management and two MCs, for symbol generation. Likewise, if the attitude select

switch is in the AUTO or INS position, back up data sources are automatically selected to provide

HUD symbology when failures are detected. Refer to figure 2-54, for the HUD displays discussed

below.

HUD Symbology Degrades with INS Failure. When a failure occurs in the INS, HUD

bank angle, velocity vector, pitch ladder, and heading indications can be expected to be

impacted. With GPS operating, the mission computer utilizes GPS information for the velocity

vector. If INS attitude is valid but INS velocities are not valid the mission computer

automatically uses the INS attitude and GPS velocities to position a non-flashing velocity

vector. With a degradation of the air data function (probe or pressure transmitter set damage

or failure) calibrated airspeed, barometric altitude, indicated Mach number, and vertical

velocity indications may be impacted.

When the INS experiences a total shutdown (dump) with the attitude select switch in AUTO

or INS, or if the attitude switch is deliberately placed in standby, a stationary waterline symbol

replaces the velocity vector indicating that the standby attitude reference indicator is now

providing attitude data. This failure is normally accompanied by the MASTER CAUTION

light, tone, and INS ATT caution. Place the attitude select switch in the STBY position,

crosscheck the HUD against standby instruments, and attempt an in-flight alignment.

Due to the tendency of the standby attitude reference indicator to precess, it is suggested that

flying in instrument meteorological conditions (IMC) using the ARI as a primary attitude

reference be minimized. A partial IFA (In-Flight Alignment) is always recommended whenever

possible to recover the INS attitude platform.

HUD Symbology Degrades with Air Data Function Failure. An air data function

failure in the FCC results in loss of associated data from the HUD display as shown in figure

2-54. Such a failure also inhibits operation of cruise flight Automatic Throttle Control and

disables the altitude signal used for IFF altitude reporting. An air data function failure may

affect cabin air flow and cabin air temperature.

The pressure transmitter set can produce erroneous signals without cautions or advisories if

the pitot tube or AOA probes receive damage. As the air data function degrades, loss of some

or all of the following data from the HUD may occur:

(1) Calibrated airspeed or barometric altitude. The loss of calibrated airspeed and/or baro-

metric altitude data results in activation of the landing gear handle warning light and tone

with the gear UP. Aircrew action is to reference the applicable standby airspeed or altitude

indicator and then silence the tone.

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(2) Angle of Attack. Loss of AOA in three or more FCC CHs causes AOA to be removed from

the HUD.

(3) Vertical velocity indicator. Pilot action on loss of the vertical velocity indication is to check

that the aircraft is in the NAV master mode and to reference the standby vertical velocity

indicator.

(4) Mach number. Pilot action on loss of the Mach number indication is to reference the

standby airspeed indicator.

If an AOA probe becomes jammed (does not move), the FCC continues to receive valid signals until

the pilot executes a maneuver that causes the reading between the AOA probes to differ more than 15°

with flaps AUTO or 5.5 to 15° with flaps HALF or FULL, depending on sideslip. HUD displayed

airspeed may be inaccurate without annunciation if a pitot tube is damaged.

A jammed, blocked, or damaged pitot tube/AOA probe may not be

annunciated if system errors are not large enough to set a caution. Be

alert for unannunciated pitot static and AOA errors during flight in icing

conditions or if damage is suspected after a bird strike or IFR basket

impact during inflight refueling.

Air data inputs from the MC are used by the INS to help smooth or dampen pitch ladder and

velocity vector position. A complete air data function failure does not immediately affect the pitch

ladder/velocity vector, but these displays eventually degrade. If subtle damage to the AOA probe is

suspected, the pilot should make a cross check of airspeed with a wingman if possible. The standby

airspeed indicator receives signals from the left pitot static probe, so it is accurate if only the right

probe is damaged. AOA checks with a wingman should be made in landing configuration if a jammed

AOA probe is suspected. Cross checking in cruise configuration may give a satisfactory cross check, but

the probe may be bent in such a way that AOA anomalies are accentuated on landing configuration.

Landing with automatic throttle control (ATC) may be affected. If damage is suspected, ATC during

landing is not recommended.

When AOA is declared invalid (e.g., AOA Four Channel failure), the HUD AOA display and AOA

bracket are removed and the AOA indexer lights and approach lights are inoperative. GAIN ORIDE

provides fixed gains to the FCS and allows the pilot to select, through the FCS status display, either

the left or right probe. The center (INS) AOA value allows the pilot to compare AOA values to select

the undamaged probe. Once selected, this probe drives the HUD AOA display, AOA bracket, AOA

indexer, and approach lights. If the incorrect probe is selected, the information provided to the pilot

and LSO may be in error but has no impact on the flight control system as the gains are fixed. Notify

the LSO that a single probe has been selected.

2.19.4.6.12 HUD Advisory Data Symbology. The displays in figure 2-53 show some of the advisories

that can appear on the HUD in the NAV master mode. The advisories are associated with nosewheel

steering and approach power compensator. Although the advisories are shown on the gear down

display, most of them can appear on the basic HUD display. Refer to Part VII for description of data

link system and advisories.

The automatic throttle control/nosewheel steering advisories are displayed above the distance

display whenever the ATC or the NWS is engaged. If the ATC is disengaged by any means other than

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actuation of the ATC engage/disengage switch, the advisory is flashed for 10 seconds before it is

removed from the display or, if a pilot attempt to engage ATC is not successful, ATC is flashed for 10

seconds and removed.

2.19.4.6.13 HUD BIT Checks. The HUD has two methods of built-in tests: manually initiated and

automatic test. Refer to BIT-Status Monitoring Subsystem for the procedures and displays used for

the HUD BIT checks.

2.19.4.7 CRS Set Switch. The course set switch manually sets the desired course on the HSI display.

2.19.4.8 HDG/TK Set Switch. The heading/ground track set switch manually sets the heading

marker on the desired heading/ground track on the HSI display.

2.19.5 Up Front Control Display (UFCD). The UFCD is on the main instrument panel below the

HUD in the front cockpit. In the rear cockpit, the UFCD is located above the AMPCD. The UFCD is

an active matrix liquid crystal display with an IR touchscreen used for data entry inputs consisting of

digits or NEWS, and control of the CNI systems (data link/radar beacon/ILS, autopilot modes,

TACAN, IFF, UHF/VHF radios, radar altimeter, and AEA. See figure 2-56. In addition, the

touchscreen can be used as a multi-function display for display formats, including video. The UFCD

is used in conjunction with the two DDIs, the AMPCD and the MPCD to enter navigation, sensor,

electronic attack, and weapon delivery data. UFCD option selections and inputs are transmitted

directly to the MPCD and on to the mission computers. (The mission computers pass these inputs to

the control converter (CC) for CNI equipment control). The UFCD is NVG compatible. The front and

rear cockpit UFCDs operate independently. When different formats are being displayed, the only data

common to both UFCDs is radio channel and frequency information. Both cockpit UFCDs present the

results of changes to radio channels or frequencies at the same time, regardless of which cockpit

performed the change. The cockpit not performing data entry does not see touch highlights as the data

is entered, only the result of the data entry. If both pilot and EWO enter digits on the keypad for the

same option, both entries are accepted, with the second entry overwriting the first. When pilot and

EWO are on the same data entry or CNI format, asterisks are provided in the top left and right of the

scratch pad.

The aft UFCD is electrically controlled through the AMPCD Off/On/Brightness knob. The aft

UFCD flashes STANDBY when the MC1 communication to the UFCD is disrupted. A standby display

pattern in the the center of the UFCD display surface, similar to the DDI pattern, indicates degraded

image processing from MC1. When the Mono video connection from the AMPCD is lost or degraded,

the aft UFCD will not display anything. When video synchronization is lost or degraded, the aft UFCD

may display symbology that is not coordinated with the video. If the interface between MC1 and the

aft UFCD is lost, the touch screen capability and brightness/contrast control will not work. When MC1

is inoperative, the aft UFCD is not capable of displaying format symbology or analog video.

When the pilot or EWO touch a keypad option on the touch screen a highlight appears indicating

that the option has been selected. Figure 2-56 shows an example of a selected option. When a new

format is selected on the touchpad, the highlight does not remain on the new format.

Keypad options use a first finger in mechanization. Only one option can be selected at a time. If two

or more selections are attempted at one time, none of them are considered valid.

Some formats initialize with data in the scratchpad, e.g., the COMM sublevel of the CNI format

initializes with the comm frequency in the scratchpad. When data entry is started, the digits in the

scratchpad are blanked, allowing data entry. If a comm frequency is being entered the decimal remains

displayed, allowing frequency entry in relation to the decimal point to be viewed.

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Uncommanded option selections may occur with a malfunctioning

UFCD. This can include uncommanded autopilot selection or deselec-

tion. In order to reduce the flight safety risk, a UFCD that self-selects

uncommanded options should be secured in flight and only turned on if

required for safety-of-flight functions (radio, IFF or navigation selec-

tions). The malfunction may or may not be present when turned back on,

but can be expected to reoccur during flight if operational. An unaffected

UFCD may remain on and in use with no adverse effect. A frozen

unresponsive display is the result of another unrelated failure mode that

may occur and can be corrected by cycling power to the MPCD.

NOTE

Securing the UFCD will reset the MPCD and cause a transitory

display loss.

2.19.5.1 UFCD Data Entry. All data are entered into the scratchpad using the digit, shifted, or

alphanumeric keypad followed by selecting the option directly. In some cases, the entered data is

displayed below the option legend. The scratchpad is cleared following valid data entry.

Various types of error checking are performed on entered data. If an error is detected, ″ERROR″ is

flashed in the scratchpad, alternating with the scratchpad data. The ″ERROR″ message is removed by

a single selection of the CLR keypad option, resulting in the display of the scratchpad data as it existed

before the error occurred.

2.19.5.1.1 Data Entry Using the Keypad. Digits 0 - 9 can be entered through the keypad.

1. Clear (CLR) Option. The UFCD uses a double clear mechanism. The first selection of the CLR

keypad option removes the last digit that was entered in the scratchpad. The second selection of the

CLR option removes all the digits which have been entered in the scratchpad. If the scratchpad is

flashing due to the 10 second timer (no entries in the previous 10 seconds), selecting CLR stops the

flashing and performs the previously described CLR function. If the scratchpad is flashing due to an

error, selecting CLR stops the flashing and removes the ″ERROR″ message.

2.19.5.1.2 Data Entry Using the Shifted Keypad. The shifted keypad is entered by selecting the

N−E−W−S option and provides the ability to enter a negative sign, a decimal point, degrees, minutes,

and seconds symbols, and North (N), East (E), West (W), and South (S) entries for latitude and

longitude entries.

2.19.5.1.3 Data Entry Using the Alphanumeric Keypad. Certain UFCD options require the

alphanumeric keypad.See figure 2-55

1. Scratchpad. With the alphanumeric keypad, a flashing asterisk (*) indicates the current cursor

location if the location is blank. If the cursor location contains a character, that character is flashed

as an indication of the current cursor location. Once the desired character is selected, the cursor can

be moved to the next location either manually (right arrow) or automatically. There are two different

events that cause the cursor to automatically step to the next location:

a. The cursor automatically advances 2 seconds after the last selection of a single keypad option.

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Figure 2-55. Alphanumeric Entry Format

b. If, before the 2 seconds has elapsed, the user selects a different keypad option, the cursor

advances to the next position before beginning to cycle through the available selections of the

second keypad option. For example, if the user selects A, then immediately selects D, the

scratch pad then reads AD as opposed to just D.

The user can manually advance the cursor by selecting the right arrow option. The right and left

arrow selections also allow the user to move the cursor to any position in the string for editing purposes.

Editing of characters is performed in insert mode (as opposed to an overwrite mode). For example,

adding a character in the middle of a string results in every character under and to the right of the

cursor being moved right one position and the new character being inserted into the empty space.

2. Keypad. Characters are entered into the scratchpad by selecting various keypad options. The

keypad options function similar to the multi−press text entry mechanization of most cell phones;

multiple selections of the same button cycles through a small set of available alphanumeric

characters. Keypad options 2 through 9 cycle through the alphanumeric characters displayed in the

option; alpha characters first, then the numeric character. Keypad option 1 cycles through the

following characters, in order listed: one (1), period (.), comma (,), minus (−), question mark (?),

colon (:). Keypad option 0 always enters the zero (0). There are no other alphanumeric characters

assigned to this keypad option.

3. Clear (CLR). There are 3 different results on the first, second and third subsequent selections of

the CLR keypad option. The selection of any other keypad option before the second or third

selection of CLR resets the CLR function back to the first selection state.

a. First Selection of CLR − If there is a flashing ″ERROR″ message, the first selection of the CLR

keypad option clears out the flashing message, leaving the last entered data intact. Otherwise,

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if the cursor is at the end of the data, it deletes the last entered character and moves the cursor

back one position. Alternatively, if there is no flashing ″ERROR″ message and the cursor is

positioned somewhere other than the end of the data, the first selection of the CLR keypad

option deletes the character currently under the cursor and shifts all characters to the right of

the cursor left one position.

b. Second Selection of CLR − The second subsequent selection of the CLR keypad option deletes

a whole word and shifts the characters to the right of the deleted word left. If the cursor is

positioned within a word, that word is deleted. If the cursor is positioned over a space, the first

word to the left of the cursor is deleted. If there is no word to the left of the cursor, no action

is taken. For this function, any contiguous sequence of characters situated between spaces is

considered a word.

c. Third Selection of CLR − The third subsequent selection of the CLR keypad option removes

all the characters which have been entered in the scratchpad and positions the cursor at the

first location.

4. Back Space (BCKSP). BCKSP selection deletes the character to the left of the cursor and shifts

the cursor. All characters under and to the right of the cursor move left, one position. If the cursor

is at the first position in the string, no action is taken.

5. Number Lock (NUMLOCK). NUMLOCK selection toggles number locking on and off. When on,

the NUMLOCK option is bordered (highlighted) and selection of the keypad options enters

numbers only (the letters are still displayed on the keypad options).

6. Left Arrow. Selection of the left arrow will move the cursor one position to the left. If the cursor

is already in the first position of the scratchpad, but is not at the beginning of the string, the string

will be scrolled right and the cursor is placed in the appropriate character position. If the cursor is

already at the first position in the string, no action is taken. A solid box will be displayed in the upper

left corner of the left arrow to indicate that more characters exist to the left of those currently being

displayed in the scratchpad.

7. Right Arrow. Selection of the right option arrow moves the cursor one position to the right. If the

cursor is already in the last position of the scratchpad, but is not at the end of the string, the string

will be scrolled left and the cursor is placed in the appropriate character position. If the cursor is

already at the last position in the string, no action is taken. A solid box will be displayed in the upper

right corner of the right arrow to indicate that more characters exist to the right of those currently

being displayed in the scratchpad.

2.19.5.2 UFCD CNI Function. The aircraft powers up with all CNI systems off and the top level CNI

format as the default UFCD display. See figure 2-56. This format is the central point for controlling all

CNI systems. The MAN option is used to turn to a previously entered manual radio frequency. For

Communication-Identification Equipment, see Chapter 23. For Navigation Equipment, see Chapter

24.

2.19.5.3 UFCD NON-CNI Functions. The following top level options are not related to CNI systems:

DDI, and AEA. The DDI option provides the last selected DDI display on the UFCD. The AEA option

provides the specified display format on the UFCD.

2.19.5.3.1 AEA Power Control. Selecting AEA option displays the AEA power control format. EAU,

SAT, CCS, and INCANS options are displayed when the functions are available.

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2.19.5.3.2 EAU Power Control. The mission computers default the EAU power to on if the MCs are

powering up after a cold start and if the power up is not after an erase. A single selection of the EAU

OFF option on the AEA Power Control format applies power to the EAU. EAU power on is indicated

by a corner highlight in the upper left corner of the EAU option pushtile, and the legend changes to

EAU ON. When the EAU is powered up and communicating with the MCs, options to power up the

ALQ-218, CCS, and the ALQ-99 Pods are available. Once the EAU is on, pressing EAU ON causes an

EAU OFF ENABLE option to appear. Pressing the EAU OFF ENABLE option (within 3 seconds)

removes power from the EAU. Turning off power to the EAU also removes power from the ALQ-218,

CCS, and all ALQ-99 Pods. The EAU automatically shuts down when overheated.

2.19.5.3.3 INCANS Power Control. Pressing the AEA option and then the INCANS option turns on

the INCANS system and places it in the STBY mode. Pressing the INCANS pushbutton again turns

off the INCANS system.

2.19.5.3.4 MATT Power Control. Pressing the AEA option and then the SAT option turns on the

MATT system. Pressing the INCANS pushbutton again turns off the INCANS system.

2.19.5.4 UFCD STANDBY Indication. A flashing STANDBY indication is provided just above the

center of the UFCD display surface when there is no valid mux communication between the MC and

MPCD. The STANDBY indication is superimposed over any display format. When the STANDBY

indication is displayed, power to the MPCD should be cycled to attempt a reset. If the STANDBY

condition clears before power can be recycled, the UFCD screen blanks and the previously displayed

format reappears.

2.19.5.4.1 Aft UFCD MUX FAIL. The aft UFCD generates a MUX FAIL BIT indication when MC1

loses communication with the UFCD. This message occurs only when the AMPCD is turned on and

powering the aft UFCD. Using periodic BIT monitoring, the MC1 tries to reset the aft UFCD through

the AMPCD communication if an error is detected.

2.19.5.5 Radar Altimeter (RALT) Function. The RALT function indicates clearance over land or

water from 0 to 5,000 feet. Operation is based on precise measurement of time required for an

electromagnetic energy pulse to travel from the aircraft to the ground and return. A warning tone and

visual warnings are activated when the aircraft is at or below a selectable primary or secondary low

altitude limit. The primary/secondary radar low altitude warnings are reset by setting the low altitude

index (primary), or UFCD selected altitude (secondary) to an altitude below the present altitude or by

climbing above the previously set limit. The warning tone can be disabled in either cockpit by pressing

the flashing RALT option on the UFCD Low Altitude Warnings format or UFCD DDI format, turning

off the radar altimeter, setting the warning value below current radar altitude, or by climbing above the

warning altitude. When disabled, the tone cannot be triggered until after being reset as described.

The radar altimeter consists of a receiver-transmitter and individual transmitting and receiving

antennas. The receiver-transmitter produces the energy pulses, transmits the energy to the ground,

receives the reflected signal, and processes the data for display as altitude by the head-up display unit

(HUD).

Indicators and controls used with the electronic altimeter set are the left or right DDI on the

instrument panel (for BIT checks), the ALT switch, UFCD (for secondary low altitude warning), and

the head-up display. Radar altimeter BIT is initiated from the BIT display.

Pressing the emission control (EMCON) switch on the UFCD inhibits operation of the radar

altimeter. EMCON is toggled on or off each time the EMCON switch is pressed. When EMCON is on

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the letters E, M, C, O, N are displayed either in the left side option boxes (DDI display) or in the

scratchpad of the top level CNI display and on the HUD.

2.19.5.5.1

Low Altitude Warning Tone. When the aircraft descends below the primary low altitude

set in the UFCD, a ‘‘Whoop, Whoop’’ warning tone is heard in the aircrew’s headset and the word

ALTITUDE is displayed on the HUD. The warning tone, when initiated by the primary radar low

altitude warning, is repeated at the lowest priority until reset or disabled.

Numbers ending in zero are valid entries for both the Low Altitude

Warning and COMM 1. Due to the close proximity of the COMM 1 and

RALT options, it is possible to inadvertently change the low altitude

warning setting for the radar altimeter when attempting to use COMM 1

fast data entry.

A barometric low altitude and secondary radar low altitude warning function are enabled by entering

the appropriate altitude, up to a maximum of 25,000 (BARO) and 5,000 (RADAR), on the UFCD. The

barometric low altitude and secondary radar low altitude warning provide a single voice alert warning

“ALTITUDE, ALTITUDE” when the aircraft descends through the selected altitude. Refer to Part VII

for information on entering altitude. The barometric low altitude warning function does not affect the

operation of the radar altimeter low altitude warning function.

2.19.5.6 UFCD Controls. A description of UFCD switches follows. Refer to Part VII for operating

instructions for CNI equipment.

2.19.5.6.1 COMM 1 and 2 Channel Knobs. The COMM 1 and 2 channel knobs permit independent

selection of up to 20 preset channels on radios 1 and 2. Guard (G), Manual (M), Ship Maritime (S), and

SINCGARS Cue (C) channels are also available on the continuously rotatable knobs.

2.19.5.6.2 COMM VOL Knobs. The VOL knobs independently control radio volume for COMM 1 and

2. The OFF position (detent) is at the full counterclockwise position. Both sets of knobs must be in the

OFF position for power to be removed from the radios. When a radio is powered, the respective COMM

option is corner highlighted. When a radio is actively receiving, a half intensity highlight is shown on

the upper half of the COMM option (figure 2-56).

2.19.5.6.3 ID (IDENT) Pushbutton. The ID pushbutton commands an IFF identification/position

squawk (IDENT), for modes 1, 2, and 3 (if enabled).

2.19.5.6.4 UFCD BRT Knob. The BRT knob adjusts the overall brightness of the UFCD display, both

symbology and video. Turning the knob counterclockwise to the OFF position removes power from the

UFCD.

2.19.5.6.5 UFCD CONT Knob. The CONT knob adjusts video contrast on the UFCD.

2.19.5.6.6 UFCD SYM Knob. The SYM knob is used to adjust the brightness of the UFCD symbology

without affecting the brightness of the UFCD video.

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2.19.5.6.7 EMCON Pushbutton. If the UFCD is displaying a DDI format the letters E M C O N are

displayed in the left side option boxes. If the UFCD is displaying the top level CNI format, EMCON

is displayed in the scratch pad.

2.19.6 Signal Data Computer (SDC). The signal data computer (SDC) operates under mission

computer control and records aircraft fatigue strain data, engine parameters when out of tolerance

conditions occur, fuel information, and aircraft and target parameters when targets are designated and

weapons are delivered. It includes fuel transfer controls and gaging capabilities, incorporates ground

support equipment fuel transfer and gaging fault isolation functions, and provides interface for

multiple sensors and controls. It provides analog-to-digital conversion of aircraft parameters. In

addition, BIT fail indications are stored in the SDC to be displayed by the maintenance status panel

(MSP) for readout by maintenance personnel after the flight, or on the EFD for readout during the

flight.

The RESET SDC option is available from the SUPT MENU/FUEL format. This option is used to

reset the SDC by momentarily removing power. When selected, the RESET portion of the option

legend is boxed, and remains boxed until the SDC reestablishes AVMUX communication or 15 seconds

after the option was selected. The RESET SDC option is removed from the FUEL format if the CSC

is not communicating on the AVMUX.

The SDC is used to compensate for periods of blank cockpit displays and interrupted avionics

multiplex (AVMUX) bus communication occurring when both advanced MCs are off-line or in

initialization. The SDC will take temporary control of AVMUX busses 1 and 6 during the ground start

and inflight conditions. While acting as the backup bus controller, the SDC transmits to the forward

MPCD and forward UFCD a limited HUD display of essential flight information. Refer to chapter 25.

Additional data transfers to the left and right Full Authority Digital Engine Controllers (FADECs) and

the Environmental Control System (ECS) Controller sustains standard operation. The SDC also

enables display of the Left and Right Air Turbine Starter (L ATS and R ATS) cautions.

2.19.7

Cockpit Video Recording System (CVRS).

The system has the capability to direct record various combinations of either front DDI, aft DDI,

MPCD, AMPCD, the HMD, and the HUD in color. Headset audio is also recorded as long as the

KY−58 encryption function is inactive. The switches to operate the CVRS are located on the VIDEO

RECORD panel in each cockpit.

The CVRS consists of one SSR with removable memory module (RMM).

2.19.7.1 Solid State Recorder (SSR). The SSR is located in the avionics bay behind behind the rear

cockpit ejection seat. The SSR provides a minimum of 3 hours recording time on a removable memory

module (RMM).

2.19.7.1.1 SSR Advisories. The RMMCD and RMMFL advisories are described in the Warning/

Caution/Advisory Displays in part V.

2.19.7.2 HUD Camera. The HUD camera, positioned immediately in front of the HUD, records a

color image similar to what the pilot sees through the HUD, e.g., symbology superimposed on a picture

of the outside world. This combined image is made available for recording.

2.19.7.2.1 HUD Event Marker. The HUD event marker is a small black marker generated by the

HUD camera and positioned in the upper left corner of the video signal sent to the VTR for recording.

The event marker is displayed when the weapon release pickle button is pressed or the trigger is

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squeezed to the second detent and remains displayed until pickle button/trigger release. When

reviewing CVRS video post−flight, the event marker is a useful training aid, used to determine the

timing and duration of pickle button and trigger actuations (e.g., shot validation).

2.19.7.2.2 HUD Camera BIT Button. The BIT button, located on the front face of the HUD

assembly, is used to initiate a BIT of the HUD camera. The GO and NO GO BIT status balls, normally

black, are used to determine the BIT status of the HUD camera. When the BIT button is pressed, BIT

status is indicated by a green GO ball or an orange NO GO ball.

2.19.7.3 CVRS Control Switches. The switches used to operate CVRS are located on the VIDEO

RECORD panel on the lower left instrument panel in the forward cockpit, and below the center display

in the aft cockpit. The aft cockpit switches override the front cockpit switches for any selection. The

VTR 1 and VTR 2 sources are grouped to nominally allow front cockpit recording on VTR 2 (includes

HUD) and allow aft cockpit recording on VTR 1 (includes AMPCD).

2.19.7.3.1 CVRS Mode Switch. The CVRS mode switch is used to select manual or automatic video

recording.

MAN

CVRS records continuously (according to the inputs

selected by the two VTR selector switches).

OFF

CVRS recording off.

AUTO

CVRS records automatically only when in the A/A or A/G master modes (accord-

ing to the inputs selected by the two VTR selector switches).

2.19.7.3.2 CVRS RDCR ON Light. The green RDCR ON light, located on the left warning/caution/

advisory lights panel on the upper left instrument panel, comes on when CVRS power is on. An

illuminated light does not mean that the VTR or SSR is recording.

2.19.7.3.3 VTR Selector Switches . The VTR selector switches are used to select the video input

source for recording on the two VTRs. See figure 2-57.

Figure 2-57. Forward CVRS Control Panel

For the forward cockpit:

VTR1 switch controls selection of video to VTR1:

HMD

Selects HMD video camera (VTR1).

LDDI

Selects LDDI direct video (VTR1).

RDDI

Selects RDDI direct video (VTR1).

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VTR2 switch controls selection of video to VTR2:

HUD

Selects HUD video camera (VTR2).

RDDI

Selects RDDI direct video (VTR2).

MPCD

Selects MPCD direct video (VTR2).

NOTE

When both VTR 1 and VTR 2 have RDDI selected, the actual

recording occurs on VTR 2 only.

For the aft cockpit:

VTR1 switch controls selection of video to VTR1. Out of the FWD position overrides the forward

cockpit selection and turns CVRS on if the system is off. The switch automatically returns to FWD

when aircraft power is removed. See figure 2-57.

CNTR

Selects center display direct video (VTR1). Electrically held in this position.

FWD

Selects front cockpit video (VTR1). Default start−up position.

LDDI

Selects LDDI direct video (VTR1). Electrically held in this position.

VTR2 switch controls selection of video to VTR2. Out of the FWD position overrides the forward

cockpit selection and turns CVRS on if the system is off. The switch automatically returns to FWD

when aircraft power is removed.

HMD

Selects HMD video camera (VTR1).

FWD

Selects front cockpit video (VTR1). Default start−up position.

RDDI

Selects RDDI direct video (VTR2). Electrically held in this position.

Figure 2-58. Aft CVRS Control Panel

2.19.7.4 VTR 2 Override Function. CVRS incorporates a VTR 2 override function designed to make

sure that HUD camera video is recorded when an A/G weapon is released, or an A/A missile is

launched. In A/A or A/G master modes, when the pickle button is pressed or the trigger is squeezed to

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the second detent, VTR 2 automatically switches from the selected VTR2 source to the HUD camera.

VTR 2 records HUD video from pickle button/trigger actuation to pickle button/trigger release plus a

set overrun time before reverting to the video source selected by the VTR 2 selector switch. Overrun

times are 10 seconds for AIM−120 launch and A/G weapon release.

2.20 TACTICAL AIRCRAFT MOVING MAP CAPABILITY (TAMMAC)

The TAMMAC avionics subsystem provides a moving map capability to enhance operational

effectiveness and survivability and addresses supportability/obsolescence issues facing existing moving

map and data storage systems currently deployed.

Independent maps and related formats are available in both cockpits with Digital Video Map

Computer (DVMC) installed, allowing independent map functionality and video routing. The DVMC

provides five outputs through two channels to various aircraft displays; however, each map channel

output is not available on every display. DVMC Channel 1 (using MC1) has two analog video outputs.

One output is viewable on the front LDDI, MPCD and rear LDDI. The other channel 1 output is used

for the aft UFCD. DVMC Channel 2 (using MC2) has two analog video outputs and one digital color

fiber optic output. One of the analog outputs is viewable on the front and rear RDDIs, and AMPCD.

The other analog output is used for Wrap-Around-Test (WAT) and removes video capability from the

front UFCD. Channel 2 digital (fiber optic) is only available on the AMPCD. When the Channel 2

digital output is in use on the AMPCD, the analog outputs are disabled. The DVMC only produces

digital or analog on Channel 2 at any time, not both simultaneously.

The AMPCD processes analog video (via MC1 or MC2) or digital video, via Fiber Channel Network

Switch (FCNS) 2 along with the symbology received from MC2 to create a composite format display

image. Map mono video (Wrap-Around-Test only) is the only analog videos routed to the AMPCD.

The aft UFCD video displays are routed through the AMPCD for processing, and include sensor,

weapon, and TAMMAC DVMC. Digital color map video on the AMPCD is routed from the TAMMAC

DVMC via the High Speed Video Network (HSVN) and FCNS2. If FCNS2 fails, no digital color video

is available on the AMPCD. Map video routing is shown in figure 2-59.

The TAMMAC subsystem consists of the Digital Memory Device (DMD), the CP-2414/A digital

map computer and a High Speed Interface Bus (HSIB) which connects the two. Data Transfer Devices

(DTDs) used in conjunction with TAMMAC for transferring data to and from ground-based stations

are Personal Computer Memory Card International Association (PCMCIA) cards or PC cards.

Ground-based stations that process data for TAMMAC include the Joint Mission Planning System

(JMPS) and the Automated Maintenance Environment (AME). Theater data is installed on the map

loading card using JMPS.

The DMD contains two PC card receptacles, one for maintenance (ground support) operations and

one for mission (pilot) operations. This configuration allows maintenance and mission data to be

separated both pre- and post-flight which reduces logistics coordination and facilitates operational

readiness. Three types of PC cards are used in the TAMMAC subsystem operation: 1) Mission Card,

2) Maintenance Card, and 3) Map Loading Card.

2.20.1 TAMMAC Status Monitoring. Status monitoring functionality accommodates changes to the

MC/DMD/DMC interfaces including, but not limited to, the PC cards and the High Speed Interface

Bus (HSIB).

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Figure 2-60. DMD Maintenance Format

The MC verifies the DMD and DMC software configuration IDs are compatible with the MC

software.

2.20.2 DMD Maintenance Format Options and Display Information. The DMD maintenance

format contains two relay mode options, MAP LOAD and MBIT. MAP LOAD provides access to

sublevel formats used to upload map theater data to the DMC. MBIT is used for troubleshooting and

fault isolation.

Information displayed on the DMD maintenance format is limited to the MU OFP configuration ID.

The OFP CONFIG identifies the OFP version currently installed in the DMD. See figure 2-60.

2.20.3 Map Theater Data Loading. Map theater data loading can include either updates to an

existing theater load or a new theater load. In both cases, the map loading cards are processed on JMPS

and loaded in the DMC nonvolatile mass memory using the same procedure. The number of map

loading cards is contingent on the size of the update or new theater load. The number of map loading

cards can be as few as one or as many as seven.

Map theater data loading is controlled by the map loading format. The map loading format is

accessed by selecting the MAP LOAD option (PB 11) on the DMD maintenance format as shown in

figure 2-60. The map loading format contains three relay mode options; LOAD, ABORT, and RTN.

2.20.4 Map Loading Format Options. The LOAD option (PB 11) is used to initiate a theater load

when a map loading card is installed in the DMD maintenance card receptacle and the DMD door is

closed. Once the process is initiated, the LOAD option is removed from the format. Multiple card

theater loads/updates require the insertion of another map card when prompted by the DDI display.

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Figure 2-61. Map Loading Format

Installing another map loading card and closing the DMD door continues the theater loading process.

This procedure is repeated until all theater data is loaded. Map loading cards can be loaded in any

sequence.

The ABORT option (PB 13) is used to abort a theater load in progress. It is removed from the

display prior to and after completion of a load. To initiate an abort, the operator presses PB 13 which

changes the option to ABORT ENABLE. Selection of ABORT ENABLE executes the abort process.

The ABORT ENABLE legend is displayed for three seconds following selection of the ABORT option.

If the operator does not select the ABORT ENABLE option within three seconds, the ABORT legend

is redisplayed. The intent of this two-step abort process is to preclude any inadvertent operator

initiated aborts from being performed. This abort process is permanent and the entire load process will

be terminated.

Aborting a theater map load causes the aborted theater to be deleted. No maps in CHRT, DTED,

or CIB will be available if a theater load is aborted. Previous theater maps are automatically deleted

upon loading a new theater.

The RTN option (PB 15) is used to return the DMD maintenance format if a theater load is not in

progress. If a theater load is in progress, the RTN option is removed from the display.

2.20.5 Map Loading Format Status Information. Status information displayed on the map loading

format provides the operator with on-line instructions and associated feedback necessary to perform a

successful theater load. See figure 2-61. The information presented is grouped into several status fields;

THEATER, STATUS, CARD/STATUS, CARD, and OPER.

The THEATER status field contains; theater identification, theater update revision letter, and the

theater update version number that is stored on the map loading card currently being loaded. If at least

one card is not installed in the DMD (to initiate the load), the field is blank. After a map loading card

is loaded the theater identification information remains displayed as other cards are loaded.

The status field below the THEATER status field contains the overall status of the loading process.

This field contains one of the following status indications:

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HALTED - Indicates the load process has been halted (between successive cards).

LOADING - Indicates the load process has been initiated and/or is in progress.

ABORTED - Indicates the load process has been aborted.

NO DMS COMM - Indicates HSIB communications with the DMC have failed.

DMS FULL - Indicates the DMC nonvolatile mass memory is full.

LOAD ERROR - Indicates the load process has failed.

WRONG CARD - Indicates the card installed in the DMD maintenance card receptacle is not a Map

loading card.

COMPLETE - Indicates the load process has successfully been completed.

CARD/STATUS fields contain status information regarding the PC cards used in the loading

process. The CARD field indicates the card ID number(s) in the theater load card set. The maximum

number of card IDs that can be displayed is seven. The card ID number(s) displayed is dependent on

which order the cards are loaded. The STATUS field below the CARD field contains the actual load

status of the card number directly above it. Once the card is installed and the load process initiated,

the field contains one of the following status indications:

L - Indicates the card is currently being loaded.

F - Indicates the card has failed to load properly.

C - Indicates the card has been successfully loaded.

If none of the above conditions exists, the STATUS field will be blank. If any card fails to load

properly resulting in an ″F″ status, the operator has the option of reinserting the card in an attempt to

obtain a successful load.

The CARD field contains the load status of the card that is currently installed. The card ID number

will be displayed followed by the percent complete (%) for the card. The percentage will be displayed

in 1% increments.

The OPER field contains instructions for the operator. The field contains one of the following

instructional status indications. If any card has yet to be installed for loading, the OPER field will be

blank.

INIT LOAD - Indicates the DMD is ready to start the load process and the LOAD option needs to be

selected.

CLOSE DOOR - Indicates the DMD door needs to be closed.

REMOVE CARD - Indicates the installed card has been successfully loaded and needs to be removed.

INSERT CARD - Indicates another card is required to complete the load process.

2.20.6 Map Loading Interruptions. Interruptions to the map theater data loading process can occur

as a result of several events: loss of power to the MC, DMC, or DMD, operator aborts, or inadvertent

transfers out of DMD relay mode.

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If the DMD experiences a power loss greater than five seconds, or if the DMC experiences a power

loss of any duration, or if the operator initiates an abort, the interruption in the loading process results

in a nonrecoverable abort and the load process cannot be recovered without reloading all the cards.

If power is reapplied to the DMD within five seconds, then the load process can be recovered with

minimum impacts. Once the operator reselects the map loading format, the status of the load prior to

the interruption is reflected on the format status fields. If a card was in the process of being loaded

when the interruption occurred, its status is blank indicating it has not been loaded. Selecting the

LOAD option reinitializes the load process following this type of interruption.

2.20.7 DMD/PC Cards Cautions and Advisories. The DMD has the ability to trigger three caution

and five advisory messages. The caution messages are: MU LOAD, ERASE FAIL, and S/W CONFIG.

The advisory messages are: Maintenance Card Advisory (MNTCD), Mission Card Advisory (MSNCD),

Classified Data Advisory (CDATA), DMD Full advisory (MU FL), and the BIT advisory.

The MU LOAD caution is generated when the DMD door is open; if the DMD fails; if the DMD

declares a card interface fail; if the DMD is mux fail or not ready; if the mission card is improperly

formatted, not installed, or is declared failed by the DMD, if the initialization data is not downloaded,

if an incorrect checksum is calculated. The MU LOAD caution is disabled while the DMD is in relay

mode or the aircraft is in flight.

The ERASE FAIL caution is generated when the DMD has failed to erase its internal RAM memory

buffer following a classified data transfer.

The S/W CONFIG caution is generated if the DMD and MC software are not compatible. When an

DMD OFP checksum failure occurs, the DMD OFP software configuration ID displayed on the S/W

configuration BIT sublevel format indicates XXXXXXXX.

The MNTCD advisory is generated when the DMD door is open, if the maintenance card is not

installed or properly formatted, or if the DMD declares a maintenance card failure. The advisory only

displays with WonW and clears in flight.

The MSNCD advisory is generated when the DMD door is open, or if there is an DMD/PC card

interface fail, or if a down load of data is incorrect, or there is a checksum failure with the data

downloaded, or if the mission card is not installed, or if the mission card is not properly formatted, or

if there is a mission card failure. The advisory only displays with WonW and clears in flight.

The BIT advisory is generated when the DMD is degraded or an DMD RAM classified erase failure

occurs.

The CDATA advisory is generated when the mission card contains classified data. It is removed

when a successful classified data erase of all avionics has been performed, or a successful classified data

erase of all avionics except the mission card is performed and the ERASE (MU HOLD) option has been

selected on the MUMI format.

The MU FL advisory indicates a data wraparound has occurred on the maintenance card and the

corresponding MSP code (809) is set. When the MC determines there is not enough memory on the

maintenance card to perform the next sequential write operation, it begins overwriting previously

recorded data.

DFIRS data download requests do not cause a data wraparound to occur. If there is insufficient

memory available, based on the current sequential write address pointer, the DFIRS data download

request is not executed.

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2.21 COUNTERMEASURES DISPENSING SYSTEM

2.21.1 ALE-47 Countermeasures Dispensing Set. The ALE-47 countermeasures dispensing set is

manually actuated. Refer to NTRP 3-22.2-EA-18G (EA-18G Classified Manual) for details on ALE-47

operation and displays.

2.21.1.1 DISPENSER Switch. The DISPENSER switch, located on the center pedestal, is used to

control power to the ALE-47 system and to enable the BYPASS dispensing mode.

BYPASS Selects the BYPASS mode for ALE-47 operation.

Powers ALE-47. Enables the ALE-47 sublevel on the EW format.

OFF

ALE-47 off

2.21.1.2 ALE-47 Advisories. The D LOW advisory is displayed when expendable loadouts drop to the

BINGO level set on the ALE-47 sublevel of the EW format. The D BAD advisory is displayed when a

dispense misfire occurs.

2.22 BIT-STATUS MONITORING SUBSYSTEM

The BIT/status monitoring subsystem, provides the aircrew with a simple display of system status.

Most information is derived from BIT mechanizations within the avionics sets and from non-avionic

built in tests implemented in the computer software for other aircraft subsystems.

The subsystem monitors engine and airframe operational status for unit failures and caution/

advisory conditions when the mission computer system is operating. When the mission computer

system detects a caution/advisory condition, it commands display of the applicable caution or advisory

message on one of the DDIs. If the mission computer system detects a unit failure, it commands the

subsystem to store the applicable maintenance code. The mission computer displays the subsystem

BIT results on one of the DDIs.

Non-BIT equipment status includes configuration ID numbers and INS terminal data.

2.22.1 Flight Incident Recorder and Aircraft Monitoring Set (FIRAMS). The FIRAMS consists of a

signal data computer, a data storage set, an engine fuel display, and a maintenance status panel. The

FIRAMS monitors selected engine, airframe, avionic, non-avionic, fuel gauging and consumable

signals. It also performs conversion of sensed measurements, provides real time clock function, outputs

discrete and analog data to associated equipment, communicates with the mission computer, displays

fuel quantities and engine parameters, and performs fuel system health monitoring. FIRAMS also

provides nonvolatile storage for flight incident, maintenance, tactical and fatigue data, and bulk data

input of tactical mission planning data.

2.22.2 Deployable Flight Incident Recorder Set (DFIRS). The DFIRS system consists of the signal

data recorder (SDR), the data transfer interface unit, and the pyrotechnic release system. The SDR

consists of the flight incident recorder memory, beacon, battery, and antenna. DFIRS is contained in

a deployable aerodynamic airfoil located on the top of the fuselage between the rudders. The DFIRS

system stores up to 30 minutes of flight data and, when activated, deploys the SDR along with a rescue

beacon in an airfoil. The SDR is deployed upon pilot ejection or on ground impact. The data stored on

the flight incident recorder (FIR) is gathered by the mission computer from aircraft systems. DFIRS

records flight data, cautions, advisories, and spin data. The FIR memory wraps around to the

beginning when the end of memory is reached. Only the last 30 minutes of each flight is retained. The

MC controls the rate and the type of data that is stored. DFIRS data recording starts when both

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Figure 2-62. Flight Aids Reversion Mechanization

throttles are advanced past the vertical, launch bar is lowered, ground speed exceeds 50 knots, or

WoffW and airspeed is over 80 knots. DFIRS recording stops 1 minute after WonW, both throttles less

than the vertical, and the ground speed less than 50 knots. All data with SPIN mode activated are

automatically recorded. A DFIRS DWNLD option is available on the engine display with WonW.

Selecting this option downloads the DFIRS data to the MU for easier retrieval.

2.22.3 Avionics BIT. In most instances, two types of BIT are mechanized, periodic and initiated.

Periodic BIT begins functioning at equipment power application. It provides a failure detection

capability that is somewhat less than that provided by initiated BIT in that it does not interfere with

normal equipment operation.

Two forms of BIT derived data are supplied to the MC. One form is validity information associated

with selected data. The second form is equipment failure information which identifies failed

assemblies. The MC uses these two forms of BIT data to implement reversion operation and advisories

for the aircrew as well as equipment status displays for both the aircrew and maintenance personnel.

2.22.3.1 Reversion. When the BIT equipment determines that a function has exceeded a predeter-

mined threshold, the data derived from that function is immediately indicated as not valid. The MC,

upon receiving this indication, reverts to the next best available source. This source is, in many cases,

as accurate as the original source. This reversion is maintained as long as the data remains invalid from

the primary source.

Figure 2-62 illustrates this concept for the flight aids. For each unit in the primary path, there is at

least one alternate source of data for reversion. The aircrew is provided appropriate display cueing only

when a reversion results in some loss of capability or performance. If the ALT switch is in RDR and

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the radar altimeter fails, the MC removes the displayed radar altitude, replaces it with barometric

altitude, and replaces the ″R″ cue with a flashing ″B″ cue. If altitude is lost from the FCC and the

altitude switch is in BARO, the MC removes the displayed altitude from the HUD. These examples

illustrate three forms of degraded mode advisories: (1) reversion to an alternate data source of

equivalent accuracy with no cueing; (2) reversion to an alternate data source of lesser accuracy with

cueing; (3) and removal of displayed data when no acceptable alternate source is available. Refer to

Part VIII for further discussion on weapon system reversions.

2.22.3.2 Equipment Status Displays. Equipment status displays (BIT, caution, and advisory)

provide the aircrew with continuous status of the avionics equipment and weapons. A cue to check

equipment BIT status is the appearance of the BIT advisory display on the caution/advisory. The

display is normally on the left DDI. A MENU selectable top level BIT format displays the status of

failed, NOT RDY, or OFF systems of all avionics equipment that interface with the MC. When the BIT

control display is selected on another display, the BIT advisory is removed until another BIT failure

occurs. The AMPCD messages appear as ACNTR. Messages displayed as a function of equipment

status are listed in figure 2-63.

Weapon and stores status is displayed primarily on the stores display (selected from the menu

display). When the BIT display indicates a stores management system (SMS) failure, the affected

stations and degree of failure are identified on the stores display as described in NTRP 3-22.2-EA-18G

(EA-18G Classified NATIP).

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STATUS

APPLICABLE SYSTEM

MESSAGE DEFINITION

MESSAGE

NOT RDY

All systems except MC1

Equipment OFF, not installed, or initializ-

ing.

OFF

ALQ-99, ALQ-218, CCS, EAU, INCANS,

Equipment OFF.

MATT, RDR, MPCD, ACNTR, UFCD,

CAM, IFF, RALT, BCN, ILS, TCN, COM1,

COM2, D/L

IN TEST

All systems except MC1, MC2, RWR

Initiated BIT in progress.

SF TEST

ALQ-99, ALQ-218, CCS, EAU, INCANS,

Self test in progress (cannot be operator ter-

MATT, SMS, RDR, MPCD, ACNTR,

minated).

UFCD, RALT, WPNS, LTDR, DFIRS, GPS

ALE-47, DBFS, ECS, FADEC

All systems

Initiated BIT completed without failure.

DEGD

All systems except MC1, MC2

Failure detected; equipment operation de-

graded.

DEGD

ALQ-99, ALQ-218, CCS, EAU, DMD,

Detected failure and overheat.

INCANS, MATT, LDT, SMS, MPCD,

OVRHT

ACNTR, UFCD, CAM, CSC, FCSA, FCSB,

INS, ASPJ, RWR, LTDR, DFIRS, FADEC

OVRHT

ALQ-99, ALQ-218, CCS, DMD, EAU,

Overheat.

INCANS, MATT, LDT, SMS, MPCD,

ACNTR, UFCD, CAM, CSC, FCSA, FCSB,

INS, ASPJ, RWR, LTDR, DFIRS, FADEC

MUX FAIL

ALQ-99, ALQ-218, CCS, DMD, EAU,

Equipment is not communicating on

INCANS, MATT, CLC, SMS, RDR, LDDI,

AVMUX and on/off discrete is set to on.

RDDI, MPCD, ACNTR, CSC, MC2, FCSA,

FCSB, INS, COM1, COM2, D/L, ASPJ,

AISI, SDC, MU, LTDR, DMC, DFIRS,

GPS, ALE-47, ECS, FADEC, UFCD (Aft)

RESTRT

All systems except MC1, MC2, RWR,

Reinitiate BIT; equipment did not respond

FADEC

to BIT command, remained in BIT too long

and was terminated by MC.

OP GO

ALQ-99, ALQ-218, CCS, EAU, DMD,

Non critical BIT failure detected.

INCANS, MATT, SMS, COM1, COM2,

WPNS, MU, DFIRS, GPS, ALE-47, FADEC

PBIT GO

All systems except MC1, MC2, RWR,

Initiated BIT has not been run since ground

FADEC

power-up and PBIT is not reporting any

failures.

No indication (blank) adjacent to the equipment legend indicates that initiated BIT has not been run on the

equipment and that the periodic BIT has not detected any faults. LDDI, RDDI, MPCD, and EFD have

unique degraded messages of ALDDI, ARDDI, ACNTR, AEFD, and AUFCD to allow distinguishing BIT

status failures for aft cockpit displays.

Figure 2-63. Equipment Status Messages

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Figure 2-64. Caution/Advisory Displays

2.22.3.2.1 Cautions and Advisories. Cautions and advisories are displayed (figure 2-64) on the left

DDI except when the left DDI is used for BIT display or weapon video. When the left DDI is off or

failed, or when the LDDI is used for BIT or weapon video, cautions and advisories are displayed on the

center display. If the left and center displays fail or are turned off, the right DDI displays the cautions

and advisories. Cautions and advisories automatically move to the center display when BIT is selected

on the LDDI. Caution displays appear as 150%-size letters compared to the normal message symbology

size. Cautions are displayed as they occur beginning in the lower left portion of the DDI display and

sequence to the right up to three displays across. The fourth caution reindexes to the left edge above

the first caution. A dedicated caution display automatically replaces the HSI display if the number of

cautions exceeds 3 lines. Advisory displays appear as 120%-size letters on a single line beneath the

caution displays. The advisories are preceded by an ADV- legend and the individual advisories are

separated by commas. A caution or advisory is removed when the condition ceases. If there is a caution

or advisory displayed to the right of the removed caution or advisory the display remains blank.

Pressing the MASTER CAUTION light when the light is out repositions the remaining cautions and

advisories to the left and down to fill the blank displays. When a caution occurs, the MASTER

CAUTION light on the main instrument panel illuminates and the MASTER CAUTION tone or a

voice alert is heard in the headset. The MASTER CAUTION light is extinguished by pressing the light.

Refer to Warning/Caution/Advisory Displays in chapter 12 for the display implications and corrective

action procedures.

2.22.3.3 BIT Initiation. In addition to displaying equipment BIT status, the BIT top level and ten

sublevel displays (figure 2-65) are used to command initiated BIT. Those avionics set groups identified

by the legends on the top level display periphery have an initiated BIT capability. BIT may be initiated

for all operating units simultaneously except for some BIT that cannot be performed in flight. Figure

2-65 shows which initiated BIT are not allowed in flight. Additional steps are required to test the INS

and FCS. BIT for individual units within groups may be initiated through the BIT sublevel displays.

Pressing BIT returns to the BIT top level display. Pressing STOP or MENU when BIT is in progress

terminates initiated BIT. Performance of BIT assumes that the required electrical and hydraulic

power is applied to the equipment tested.

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2.22.3.3.1 All Equipment. Simultaneous initiated BIT of all equipment installed is performed by

selecting AUTO on the BIT top level display. Equipment group, acronym and status are displayed at

the display options. Equipment group status indicates the lowest operating status reported by any unit

in the tested group. Individual system status results other than GO, PBIT GO, IN TEST, SF TEST,

and OP GO are displayed with a system acronym in the center of the display. If the equipment list is

too long to be displayed on one page, a PAGE pushbutton is displayed. Pressing PAGE displays the

remainder of the list that is on page 2. Pressing PAGE when page 2 is displayed returns page 1.

2.22.3.3.2 Equipment Groups. Initiated BIT of entire equipment groups is performed by selecting

SELBIT (SELBIT option becomes boxed) on the BIT top level display and the desired equipment

group pushbutton. One or more groups can be selected. Another way to select a group is to press the

group pushbutton (with the SELBIT option not boxed) on the BIT top level display and then ALL on

the group sublevel display. See figure 2-65.

2.22.3.3.3 Individual Units. Initiated BIT of an individual unit is performed by pressing the

equipment group pushbutton on the BIT top level display which contains the desired unit. The display

changes to a group sublevel display. Individual units from the group can then be tested by pressing the

pushbutton adjacent to the desired acronym. System status for all systems in the group is displayed on

the center of the display. Some systems require additional aircrew BIT input.

2.22.3.4 System BIT Steps. The following includes certain initiated BIT which require steps in

addition to pressing one of the buttons on the BIT display and reading the BIT status messages after

the test is complete. Figure 2-65 shows which initiated BIT are not allowed in flight.

2.22.3.4.1 FCS Initiated BIT (IBIT). For the FCS to enter IBIT the FCS BIT consent switch must be

held ON. This action prevents inadvertent IBIT initiation inflight for reasons of flight safety.

Control surfaces move during FCS IBIT with hydraulic power applied.

To prevent personnel injury or equipment damage, make sure personnel

and equipment are kept clear of control surfaces.

NOTE

• With the wings folded, both ailerons are Xd out, but no aileron BLIN

codes should be displayed. Even with wings folded, there are aileron

functions tested that may reveal FCS failures via valid BLIN codes.

• For FCS IBIT to start, the FCS BIT consent switch must be held for

at least 2 seconds. If not held for the required time, FCS A and FCS B

will indicate RESTRT on the BIT status line. If RESTRT is dis-

played, select STOP on the FCS-MC sublevel display and then repeat

the initiation procedure.

• The FCS will not enter IBIT if the throttles are above 14° THA or

NWS is engaged.

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NOTE

• Do not operate any FCS related switches or move the stick or rudder

pedals while FCS IBIT is running, as this may produce false failure

indications

• With the wings folded, a BIT status of GO will only be displayed for

approximately 2 seconds before reverting to a DEGD indication. BIT

status will return to GO when the wings are spread and locked.

• If the FCS IBIT fails, FCS A and FCS B will indicate DEGD on the

BIT status line. Note surface Xs and/or BLIN codes and contact

maintenance personnel for disposition.

1. Select MENU-SUPT/BIT/FCS-MC on right DDI.

2. While simultaneously holding FCS BIT consent switch to ON, select the FCS pushbutton on the

FCS-MC sublevel display.

3. Release FCS button and FCS BIT consent switch when FCSA and FCSB BIT status indicates IN

TEST. FCS IBIT requires approximately 1 minute.

NOTE

If IN TEST remains on the FCS BIT display longer than 2 minutes,

select STOP and actuate the paddle switch to exit FCS IBIT.

2.22.3.4.2 Preflight FCS Initiated BIT. The fly-by-wire flight control system uses redundant

hardware to provide continued safe operation after component failures. The level of redundancy

designed into the system was set by component failure rates, failure mode effects, aircraft mission time,

and survivability considerations. The ability to provide safe operation is fundamentally based on the

principle that there are no undetected (e.g., latent) failures prior to flight which would compromise

system redundancy. It is not possible to have an in-flight periodic BIT (PBIT) which can detect all

degradations in a fly-by-wire system. Many redundant pathways can be tested only by setting system

conditions that would be unsafe to establish in flight (e.g., verification of the ability to shut off an

actuator). Preflight FCS initiated BIT was designed to provide those tests and ensure the full

redundancy of the flight control system is available prior to flight. Without running preflight FCS

initiated BIT and performing the necessary maintenance, latent failures present in the system can

result in unsafe conditions should additional failures occur in flight.

2.22.3.4.3 Preflight FCS Initiated BIT Operation. Preflight FCS initiated BIT consists of a series of

tests which verify the integrity of the flight control system processors, actuators, sensors, and cockpit

interfaces.

Preflight FCS initiated BIT begins by testing lower level functions. If preflight FCS initiated BIT

detects a fault at this level which affects higher level functions, it halts and reports the fault(s). If

preflight FCS initiated BIT did not halt at this point, false BLIN codes would be generated on higher

level functions which depend upon the failed lower level function for their operation. If preflight FCS

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initiated BIT detects a fault in a subsystem (e.g., left stabilator) testing of the failed subsystem is

discontinued, and testing of unrelated subsystems (e.g., rudders, trailing edge flaps, etc.) continues.

Since testing is not complete, preflight FCS initiated BIT must be run again after maintenance actions

in order to complete all tests.

2.22.3.4.4 Preflight FCS Initiated BIT PASS/FAIL. A successful preflight FCS initiated BIT results

degradation. A preflight FCS initiated BIT never sets an X on the DDI FCS status page (MENU-FCS)

since preflight FCS initiated BIT only sets BLIN codes. Launching in a degraded state (e.g., with BLIN

codes) places the aircraft in a situation where a portion of the flight control system is operating without

the normal redundancy.

2.22.3.4.5 Repetition of Preflight FCS Initiated BIT. If an aircraft fails preflight FCS initiated BIT

(e.g., BLIN codes present after preflight FCS IBIT) maintenance should be called to troubleshoot the

system. After completing troubleshooting, a successful preflight FCS IBIT is necessary to make sure

the system is fully operational. Except for cold weather operation, preflight FCS IBIT failure is

indicative of a component degradation, e.g., hydraulic or electrical components are out of tolerance, or

a cable conductor is intermittent (broken wire, loose connector pin, etc.).

2.22.3.4.6 FCS Exerciser Mode. In cold weather, actuator components do not respond normally until

hydraulic fluid temperature increases. Exerciser mode should be used to expedite system warm-up.

During exerciser mode, a number of PBIT actuator monitors are ignored to prevent generation of

nuisance BLIN codes. In cold weather it is appropriate to re-attempt preflight BIT after running

exerciser mode. Exerciser mode should not be used as a method to clear BLIN codes in normal start-up

temperature conditions. BLIN codes cleared in this manner could be associated with hydraulic

contamination or sticking control valves which could appear again in flight with catastrophic results.

Repeatedly running exerciser mode in normal and hot weather environ-

ments may lead to hydraulic system overheat.

2.22.3.4.7 Running Preflight FCS Initiated BIT After Flight. A good (no codes) preflight FCS IBIT

on the previous flight is no assurance against latent failures on the next flight. Electronic components

have a propensity to fail on power application. Damage can occur during deck handling or maintenance

activity not associated with the flight controls. The only insurance is to run preflight FCS initiated BIT

prior to flight.

2.22.3.5 SMS Initiated BIT. Safeguards have been built into the weapon system mechanization to

allow SMS initiated BIT to be performed on the ground with weapons loaded and cartridges installed.

During initiated BIT, weapon release signals and associated circuitry are not exercised unless all of the

following interlocks are satisfied simultaneously: MASTER ARM switch to ARM, armament safety

override in override, weapon load codes on stores processor set to zero, and no weapon ID detected on

any weapon station. SMS initiated BIT should not be attempted until the above interlocks are in a safe

condition. The SMS initiated BIT should be successfully completed within 180 seconds of initiation.

2.22.3.6 INS Initiated BIT. To perform initiated BIT, the INS must be in the TEST mode and a

ground/carrier selection must be made to indicate where the BIT is being accomplished. When the

BIT/SELBIT/NAV/ALL, BIT/NAV/INS, or BIT/AUTO is actuated, a status message of GND/CV?

appears next to the INS legend in the status display area. At the same time, GND and CV button labels

appear along the bottom of the display. These options allow entry of where the initiated BIT is

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performed, e.g., on the ground or on a carrier. A third option, INS LONG (INS long test), identifies if

the platform slew portion of the INS test is desired. The platform slew test, which adds an additional

26 minutes to the normal 12 minutes INS BIT time, is only performed when the INS exhibits degraded

navigation performance during a flight and normal BIT routines do not detect any malfunction. This

option should be selected prior to selecting the ground or carrier option.

1. Check parking brake set.

2. For ground initiated BIT insure waypoint zero is local latitude/longitude.

3. Select MENU/BIT/SELBIT/NAV or MENU/BIT/NAV/INS or MENU/BIT/AUTO or MENU/

BIT/NAV/ALL on the right DDI and TEST on the INS mode switch.

4. Select INS LONG (if required) and GND or CV on DDI, and start clock. At successful completion

of test BIT, display status message reads GO. Maximum time for INS initiated BIT is 12 minutes

and maximum time for INS initiated BIT and platform slew test is 45 minutes.

2.22.3.7 AUTO BIT. If the AUTO button is pressed, BIT are initiated in parallel for all equipment

turned ON and whose interlocks are satisfied. The test pattern associated with the DDI and HUD is

not displayed when the AUTO option is used. Approximately 2½ minutes are required for all AUTO

BIT except FCS and INS.

1. Check power applied to all systems requiring BIT and check required interlocks in safe condition.

2. Select MENU/BIT/AUTO on DDI.

a. All systems read GO after required test period. GO indication is provided when system check

is complete and OK. Other messages may be displayed if malfunctions are detected.

3. If FCS test required, perform FCS Initiated BIT above while substituting the AUTO button for

the FCS button in the procedure. Insure the procedural warnings and notes are observed and that

the AUTO button and FCS BIT consent switch are held simultaneously to initiate test.

4. If INS test required, perform INS initiated BIT above while substituting the AUTO button for

the INS button in the INS Initiated BIT procedure.

2.22.3.8 Cockpit Displays Initiated BIT.

2.22.3.8.1 DDI/HUD Initiated BIT. Operator participation is required to detect failures and isolate

faults in the display equipment. The BIT/DISPLAYS/DDI-HUD option starts the MC generated test

patterns on the DDI and HUD immediately after each indicator BIT is concluded. The test pattern can

be compared on the three displays for similarity and individually for concentricity, intensity level, and

alphanumeric clarity. Options are tested by actuating all the buttons. A circle appears adjacent to the

button when the functional test is successfully completed.

IBIT takes approximately 20 to 90 seconds to complete (MC allows a maximum of 200 seconds).

During this interval, the displays cycle through a series of raster test patterns (i.e., small square of

raster, full screen of raster, small square again, and then a larger square of raster). Immediately after

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the BIT for each display is concluded, the MC generated test pattern is displayed on each of the

displays. See figure 2-66. The STOP option on the test pattern terminates the CRT test. The DDIs

alternate color of the test pattern between green, red, and yellow.

Pressing DDI-HUD initiates BIT on two different equipment display groups. The following

procedure can be used to test one or both of the display groups by performing the appropriate parts

of the procedure.

1. Select BIT/DISPLAYS/DDI-HUD

a. DDI and HUD displays go blank momentarily, flash IN TEST, and display a test pattern.

b. Check DDI test patterns are steady and in focus. See figure 2-66.

c. HUD test pattern flickers but remains on.

2. DDI and HUD displays - CHECK

a. Display commonality

b. Display concentricity

c. Proper intensity

d. Check right DDI pushbuttons (20) starting with the top left button on the horizontal row.

Circle is displayed next to each pushbutton after it is pressed.

e. Check BIT status messages for GO on the BIT displays. Front and rear indicators list results

separately.

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Figure 2-67. EFD Test Pattern

2.22.3.8.2 EFD Initiated BIT. The EFD test pattern is initiated by performing EFD BIT using

pushbutton sequence BIT/DISPLAYS/EFD and observing the test pattern display following the

completion of EFD BIT. The EFD test pattern may be observed using the following procedure.

1. Select BIT/DISPLAYS/EFD

2. EFD - observe test display

3. Select STOP or MENU to terminate test pattern

While the test pattern is displayed, selecting the MODE button or pulling the BINGO knob toggles

between the two test patterns displayed in figure 2-67. Rotating the BRT knob does not change display

intensity. Rotating the BINGO knob increments or decrements the number displayed in the lower

right corner from 1 to 12, depending on the rotation direction (clockwise or counterclockwise).

2.22.3.8.3 MPCD Initiated BIT. The MPCD receives information directly from the MC for display

and also processes the information provided for display on the UFCD. The MPCD test pattern is

initiated by doing MPCD BIT using pushbutton sequence BIT/DISPLAYS/MPCD and observing the

test pattern display following the completion of MPCD BIT. The MPCD test pattern may be observed

using the following procedure.

1. Select BIT/DISPLAYS/MPCD

2. MPCD and UFCD - observe test displays

3. Select STOP or MENU to terminate test pattern

The BIT format can be displayed on the MPCD or UFCD during DDI/HUD BIT and on the DDI

during MPCD BIT. The MPCD option initiates BIT on both the cockpit and rear cockpit MPCD.

During MPCD BIT the message MPCD IN TEST is displayed on both the MPCD and UFCD. When

IBIT is completed, the test pattern (figure 2-66) is displayed on both the MPCD and UFCD.

2.22.3.8.4 AMPCD Initiated BIT. The AMPCD executes initiated BIT by selecting ACNTR on the

Display BIT format. When selected, the AMPCD completes IBIT and displays a test pattern on both

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Figure 2-68. UFCD Test Pattern

the AMPCD and the aft UFCD. The AMPCD test pattern is the same as the DDI test pattern. The

mission computer removes the IBIT command after 10 seconds to allow viewing of the test pattern on

both displays.

2.22.3.8.5 UFCD Initiated BIT. UFCD test patterns are initiated by selecting BIT/DISPLAYS/

UFCD and observing the test pattern display following the completion of UFCD BIT. The UFCD test

pattern (figure 2-68) is obtained using the following procedure.

1. Select BIT/DISPLAYS/UFCD

2. UFCD - Observe test display

3. Select STOP or MENU to terminate test pattern

When BIT is initiated, UFCD IN TEST is displayed until BIT is completed. Selecting UFCD

initiates BIT on both cockpit displays. The UFCD test pattern is not displayed if IBIT is not initiated

on the UFCD option.

2.22.3.8.6 Radar Altimeter Initiated BIT. If BIT is initiated during RADALT time-in, the status on

the BIT display is NOT READY. If the BIT is initiated after time-in is complete, the display is GO

(indicating the radar altimeter is operating correctly), RESTRT (the BIT was not completed within

the design time limits), or DEGD (a WRA fail signal exists).

2.22.3.8.7 STOP Button. The STOP button allows the aircrew to stop initiated BIT at any time. BIT

is also stopped by pressing MENU, although MENU is not available with the DSPL/EPI/EFD/UFCD

BIT test pattern displayed. When the STOP (or MENU) button is pressed, any test in progress stops

and the equipment returns to normal operation. Exceptions to this are the radar and SMS power-on

BIT and the COMM 1/2, D/L, and TACAN BIT. The radar and SMS power-on BIT cannot be

terminated and indicate SF TEST when the MC detects the system is in BIT without having been

commanded to do so. The same is true of the COMM 1/2, D/L, and TACAN equipment which does a

canned non-interruptable BIT sequence. The mission computer terminates initiated BIT for any

equipment that it determines has taken too long to complete the test.

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2.22.3.9 Hydro-mechanical (HYDRO MECH) Initiated BIT. With SELBIT boxed on the top level

BIT format, selecting HYDRO MECH initiates ECS BIT if aircraft is WonW.

FADEC status is also provided on the HYDRO MECH display by L and R ENG A and B status

indications.

2.22.3.10 BLIN Codes. BIT Logic INspection (BLIN) codes are octal readouts identifying FCS

failures and can be read from the FCS status display. The following procedures may be used to display

and record BLIN codes. Channel 1 BLIN codes are displayed. Pressing the BLIN button displays the

next channel (1, 2, 3 and 4) BLIN codes.

1. On DDI - PRESS MENU-SUPT/FCS/BLIN

2. DDI BLIN codes - RECORD BY CHANNEL

3. Press BLIN button to view next channel BLIN codes

2.22.4 Non-Avionic BIT. Non-Avionic BIT is implemented in selected hydro-mechanical subsystems

primarily for the purpose of displaying subsystem status in the cockpit(s) (cautions and advisories)

and/or providing fault detection and fault isolation information for maintenance personnel. This status

data is provided to the status monitoring displays by the signal data computer which interfaces with

the following hydro-mechanical areas:

1. Engine/Secondary Power

2. Electrical

3. Hydraulics and landing/arresting gear

4. Fuel

5. Environmental control system and liquid cooling system

6. Controls/mechanisms/miscellaneous

The hydraulic system pressure cautions are interfaced directly by both mission computers, providing

redundancy for safety of flight.

2.22.4.1 Equipment Status Displays. NABIT cautions and advisories are displayed in the same

manner as avionics cautions and advisories.

2.22.5 Status Monitoring Backup. MC2 provides backup status monitoring if MC1 fails. It provides

an MC1 caution on the DDI indicating that MC1 has failed.

NOTE

If MC1 fails, all DDI cautions and advisories are available.

2.22.6 Non-BIT Status. Equipment status derived by means other than BIT include DDI configu-

ration display ID numbers and INS terminal data.

2.22.6.1 CONFIG Display Country ID Code. The country identifier code USN is displayed under the

CONFIG legend.

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Figure 2-69. CONFIG Display (Sample)

2.22.6.2 CONFIG Display. The ID numbers of the current operational flight program (OFP) loads for

the radar, stores management system, CLC, INS, mission computers, communication system control,

flight control computer, HMD, SDC, MU, LDT, DMC, MPCD, DDI, EW equipment, DFIRS,

FADECs, and ECS controller can be determined by selecting the configuration display (see figure

2-69). The configuration display is selected by the following procedure:

1. Select BIT from the SUPT MENU.

2. Select CONFIG.

With the configuration display selected, the current ID numbers are displayed to the right of the

equipment acronym. Refer to figure 2-69 for an example.

2.22.6.2.1 MC CONFIG Caution. An MC CONFIG caution indicates MC1 and MC2 OFP loads are

incompatible.

2.22.6.2.2 S/W CONFIG Caution. With the exception of JHMCS, a S/W CONFIG caution indicates

MC1 and MC2 OFP loads are not concurrent releases (incompatible) or an avionic equipment

processor OFP is incompatible with MC OFPs. The incompatible OFP(s) are indicated by a line drawn

through the OFP ident. If the MC OFPs are incompatible a line is drawn through both MC OFP idents.

For JHMCS, a S/W CONFIG caution and a line through the HMD S/W configuration line on the

configuration display indicates a mismatch in the BUNO in the Magnetic Compensation Data file and

the BUNO in the MC, or failure to load the initialization file into the EU.

2.22.6.2.3 OVRD Button. The override option allows the pilot to override the software configuration

logic when the software country ID codes do not agree with the aircraft country ID codes.

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2.22.6.4 INS Terminal Data. INS terminal data can be obtained if at least one update has been

performed after flight with the parking brake on. Terminal data is displayed by selecting the following

options in sequence: MENU, BIT, MAINT, INS, and POST. Note the PER (performance error rate)

and navigation time on the FLIGHT 1, POST 1 display (see figure 2-70). Select the POST option again

and note the velocity on the FLIGHT 1, POST 2 display. Turn the INS mode selector knob to OFF.

With GPS operating, if the aircraft is flown with IAF selected, the performance error rate does not

include the time flown in the AINS mode.

2.23 JOINT HELMET MOUNTED CUEING SYSTEM (JHMCS)

The JHMCS allows the aircrew to target and employ existing SRMs and High Off-Boresight

(HOBS) weapons, such as the AIM-9X, and cue the radar, and other sensors. When using JHMCS to

employ HOBS weapons, the aircrew can slave/acquire and shoot targets beyond the gimbal limits of the

aircraft radar and designate ground targets. The main display provides a monocular 20° field of view

that is visible in front of the pilot’s right eye.

The main components of the JHMCS include the helmet mounted displays, electronics unit,

HMD/AHMD off/brightness controls, aft cockpit Boresight Reference Unit (BRU), and cockpit units,

magnetic transmitter units, and seat position sensors in each cockpit. The JHMCS aircraft-integrated

components can be flown with or without the helmet system.

Increased weight and forward CG of the helmet will increase neck strain

during high or sustained g flight maneuvers.

NOTE

All aircrew shall receive simulator or dedicated ground training on

JHMCS helmet controls and displays prior to flight with JHMCS.

2.23.1 Helmet Mounted Display (HMD)/Aft Helmet Mounted Display (AHMD). Each HMD consists

of the helmet, Helmet Display Unit (HDU), Helmet-Vehicle Interface (HVI), and a universal connector

which connects the HDU to the helmet.

2.23.1.1 Helmet Display Unit (HDU). The HDU includes a CRT, Magnetic Receiver Unit (MRU),

camera, auto-brightness circuitry, uplook reticles, and visor. Aircrew can remove the HDU and

configure the helmet to accommodate the AN/AVS-9 night vision goggle system.

Make sure the HMD OFF/BRIGHTNESS switch is OFF before removing the HDU, and store the

HDU in the JHMCS stowage bag on the right bulkhead.

To prevent damage to the HDU, do not expose the HDU to a temperature

exceeding 50°C (122°F) operationally or in storage.

2.23.1.2 Helmet-Vehicle Interface (HVI) Connectors. The HDU is connected to the aircraft by the

HVI, which consists of three connectors. These connectors are the Quick Disconnect Connector (QDC),

In-Line Release Connector (IRC), and Helmet Release Connector (HRC). The Upper HVI is the

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portion of the HVI from the helmet to the QDC. The lower HVI is the portion of the HVI that is

installed in the aircraft.

The Upper HVI is routed under the survival vest (if worn) through the JHMCS bundle flue on the

Torso Harness. The QDC is seated in a Quick Mounting Bracket (QMB) attached to the lower left hand

leg strap of the Torso Harness. See figure 2-71.

The JHMCS Upper HVI (UHVI) must be properly routed through the

JHMCS bundle flue under the survival vest and the QDC secured in the

QMB to ensure that no entanglement exists with the oxygen hose.

Misrouting of the JHMCS UHVI may allow the QDC to rub against the

oxygen hose disconnect causing unintentional oxygen/communications

disconnect in-flight.

The QDC is the primary disconnect for ejection, and both normal and emergency ground egress. The

QDC can be manually disconnected for normal egress by pushing the plunger button on top of the QDC

and separating the top half. During an ejection or emergency egress the QDC is disconnected via the

QDC reset mounted lanyard when a force of 18 to 25 pounds is applied. When the QDC is not

connected, the aircraft QDC should be properly stowed in its receptacle. When the QDC is not properly

connected and the system is on, an HMD/AHMD advisory is generated.

The JHMCS QDC must be properly attached to the aircrew torso harness

quick mounting bracket to avoid possible death or severe injury during

ejection.

• Low voltage is present on the exposed QDC pins when the front HMD

control knob and/or the rear cockpit AHMD brightness control knobs

are not in OFF. To prevent a minor electrical shock from contact with

exposed pins, ensure the HMD control or AHMD brightness control

knobs are OFF whenever the QDC is disconnected and connected.

• To prevent damage to the QDC and aircraft components, ensure the

aircraft Lower HVI is properly stowed in its receptacle when in use.

NOTE

Ambient cockpit temperatures at or below

0°C (32°F) may cause

inadvertent HMD/AHMD advisories during preflight. Warming of the

QDC and quick mount bracket should remove the failure indication if

temperature is the cause.

The IRC is a back up disconnect which functions in the event of QDC failure. The IRC is attached

to the left aft console and requires a force of 100 ± 20 pounds to disconnect.

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The HRC allows the cable to disconnect should the helmet be lost during ejection. The HRC requires

a force of 100 ± 20 pounds to disconnect.

2.23.2 Electronics Unit (EU). The EU contains the main system CPU, LOS module, graphics

processors and display drive, and low voltage power supply. The CPU controls system bus interfacing,

display list generation, BIT, and other system functions. The LOS module calculates helmet LOS while

the graphics processor and display drive processes the display list and generates the helmet display. It

is located in the rear cockpit.

2.23.3 Cockpit Unit (CU). The CU contains the system high voltage power supply for helmet

displays. Both CUs are located in the rear cockpit.

2.23.4 Magnetic Transmitter Unit (MTU). The MTU is used to generate a magnetic field used to

determine HMD/AHMD position/orientation. It is mounted on the canopy frame aft of the pilot/

EWO’s left shoulder.

The MTU is energized when the HMD/AHMD is turned on. Warm-up time for the MTU is 15 to 20

minutes. System accuracy may drift up to 0.5° if the HMD/AHMD is aligned before MTU warm-up

is completed. An additional 5 to 10 minutes should be added to the MTU warm-up time if operating

in extremely cold temperatures (e.g., -40°C).

NOTE

To maintain system accuracy, run initial HMD/AHMD alignment, or

an additional HMD/AHMD alignment, after system is warmed-up.

2.23.5 Boresight Reference Unit (BRU). The BRU is located on top of the rear cockpit instrument

blast shield and dust cover. The BRU provides a reference cross inside the BRU to permit coarse and

fine alignment of the AHMD to the aircraft reference. See Figure 2-72.

2.23.6 Seat Position Sensor (SPS). The SPS is a linear potentiometer which indicates ejection seat

height to the JHMCS. It is mounted to the aft right side of the ejection seat. This seat position

information allows the JHMCS to compensate for disruption of the magnetic field in the cockpit as the

metal in the seat changes position when the seat is raised or lowered.

2.23.7 HMD/AHMD Off/Brightness Control. The front cockpit HMD off/brightness control is

located on the spin recovery panel. This rotary knob removes and applies power to the HMD, and

adjusts helmet CRT display brightness.

A BRU/HMD stacked rotary knob, located on the aft cockpit INTR LT control panel, controls the

aft Boresight Reference Unit (BRU)/HMD brightness. This rotary knob removes and applies power to

the BRU and AHMD, and adjusts helmet CRT display brightness. See figure 2-73.

2.23.8 HMD Video Recording. VTR selector switches located on the forward and aft CVRS Control

panels allow selection of HMD video recording.

2.23.9 Cautions/Advisories. When the BUNO in the Magnetic Compensation Data file does not

match the BUNO in the MC, or if the MC fails to download the initialization file to the EU, the MC

sets the SW CONFIG caution and displays a line through the HMD S/W configuration line on the

configuration display. An HMD/AHMD advisory is reported if the QDC is not properly secured to

Quick Mounting Bracket (QMB) or is disconnected, or the coarse alignment is invalid or has not been

performed.

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Figure 2-72. Boresight Reference Unit

2.23.10 Configuration Check. When the JHMCS system is turned on, the MC provides the EU with

the aircraft make, model, and tail number.

2.23.11 Built-In Test (BIT). The JHMCS BIT system includes automated start-up BIT (SBIT) and

initiated BIT (IBIT), and displays a BIT status message. See figure 2-74 for the DISPLAYS BIT

sublevel display.

2.23.11.1 Start-up BIT (SBIT). When the HMD system is turned on, SBIT starts automatically and

the internal software is loaded in the EU. SBIT cannot be stopped until it is completed. PBIT GO or

DEGD, as appropriate, is displayed when SBIT is completed.

2.23.11.2 Initiated BIT (IBIT). When the HMD (PB 11) option is selected in either cockpit on the

BIT DISPLAYS sublevel display, ENTERING IBIT flashes on both HMDs, and an initiated BIT is

performed on both helmets. When IBIT is complete a series of four test patterns, which are

automatically changed each second, are displayed on the HMD/AHMD. See figure 2-75. The test

patterns are displayed until the STOP (PB 10) option is selected. If the ALL (PB 6) option is selected,

IBIT and HMD test pattern are performed.

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2.23.10.3 Status Messages. Refer to the following for status messages and associated descriptions:

MESSAGE

STATUS

DESCRIPTION

MUX FAIL

Equipment ready discrete is high but the EU is

not communicating on either MUX bus to the

NOT RDY

Equipment ready discrete is low and the EU is

not communicating on either MUX bus to the

IN TEST

Initiated BIT in progress

RESTRT

Re-initiate BIT, EU did not respond to the

IBIT command or IBIT did not complete

within 30 seconds

DEGD

EU has detected a failure which degrades sys-

tem performance

OVRHT

EU has reported a component as overheated

DEGD+OVRHT

EU has detected a failure and EU has reported

a component as overheated

EU responded with no failures.

OP GO

EU has detected a failure which does not de-

grade system performance

PBIT GO

EU responded with no failures prior to per-

forming IBIT

2.23.10.4 BIT Recording On The Memory Unit. The MC records any failure or degrade reported by

the EU to the memory unit for fault reporting and isolation.

2.23.10.5 Overheat Condition. The system has the capability to detect an equipment overheat

condition. When an overheat condition is detected the system is automatically shut down to prevent

equipment damage.

2.23.11 HMD Maintenance. The HMD MAINT option is displayed at PB 17 of the DISPLAYS BIT

sublevel display. See figure 2-76. Pressing PB 17 boxes the option and displays STEP PAGE and STEP

LINE at PBs 14 and 15 respectively. Selecting either STEP PAGE or STEP LINE sends the

appropriate BIT data to the EU. With HMD MAINT boxed, pressing PB 17 removes the STEP PAGE

and STEP LINE displays and unboxes the HMD MAINT option.

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Figure 2-76. HMD Error Log Display

2.23.12 JHMCS Alignment. The JHMCS must be boresighted (aligned) with the aircraft prior to

every flight. Selecting the ALIGN (PB 20) option on the HMD format boxes ALIGN, selects coarse

alignment mode, and displays the FINE (PB 1) alignment option after the coarse align function is

complete. See figures 2-77 and 2-78.

The forward and aft helmets are aligned independently. The ALIGN option on the HMD format at

PB 20, when selected from the aft cockpit, initiates aft HMD align. When in aft coarse or fine align

mode the MC assigns the right AFT hand controller Designator Control (DC) switch to the HMD

format. Both forward and aft HMD alignments function the same with the exception that the aft

helmet is aligned to the BRU mounted on the aft main instrument panel.

2.23.12.1 Coarse Alignment. An alignment cross is displayed on the HUD and in the HMD. See

figure 2-77. The pilot moves the HMD to superimpose the alignment cross on the HMD over the

alignment cross on the HUD. Once aligned, the cage/uncage switch is pressed and held until ALIGN

OK is displayed in the HMD. When coarse alignment is complete, fine alignment is automatically

selected. Fine alignment (PB 1) can also be manually selected.

To perform a coarse align the EWO moves the HMD alignment cross on the HMD over the BRU

alignment reticle, figure 2-77, sheet 2. Once the crosses are aligned the EWO presses and holds the

undesignate switch on the right hand controller until an ALIGN OK status is provided on the HMD.

When the coarse alignment is complete, fine alignment is automatically selected. Fine alignment (PB

1) can also be manually selected.

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2.23.12.2 FINE Alignment. When the FINE (PB 1) option is boxed an alignment cross is displayed

in the HUD and two alignment crosses are displayed on the HMD in the vicinity of the HUD alignment

cross, figure 2-78, sheet 1. The display indicates which axis is being aligned. If azimuth and elevation

is indicated (FA DXDY), the pilot moves the TDC either left or right to align in azimuth, up or down

to align in elevation. The pilot presses and releases the cage/uncage switch when satisfied with the

quality of the azimuth and elevation alignment. This causes the display to toggle to roll alignment

mode. With the roll axis indicated (FA DROLL), TDC inputs to the left or right are used to rotate the

HMD alignment symbols to align with the HUD alignment cross. The pilot presses and releases the

cage/uncage switch when satisfied with the quality of the roll alignment. Pressing and releasing the

cage/uncage switch continues to toggle between these two modes until the pilot deselects FINE to

return to coarse alignment or exits alignment.

Upon entering fine alignment, automatically, or if commanded by the EWO selecting the FINE

option, the EU indicates which axis is being aligned. If the azimuth and elevation axis is indicated, the

EWO uses the DC to move the crosses up/down and left/right to align with the cross displayed on the

BRU, figure 2-78, sheet 2. When satisfied with the alignment, the EWO presses and releases the

undesignate switch on right hand controller at which time the EU automatically switches to roll

alignment. The EWO uses the DC to rotate the cross so that it aligns with the cross displayed on the

BRU. When satisfied with the quality of the alignment the EWO presses and releases undesignate

switch on right hand controller.

2.23.12.3 Alignment Exit. Alignment is exited whenever ALIGN is deselected (unboxed), an A/A

weapon is selected, MENU is selected, TDC priority is reassigned, ACM mode is selected, or the master

mode is changed. This removes the alignment cross from the HUD, removes the FINE option, unboxes

ALIGN, and returns the cage/uncage function to the previously assigned system.

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Figure 2-79. Alignment Verification

2.23.12.4 Alignment Verification. When the HMD is in normal mode a cross is displayed on the

HUD at the reported HMD LOS. See figure 2-79. If the reported HMD LOS is outside the HUD FOV,

the cross flashes at the HUD FOV limit.

2.23.12.5 HUD Symbology Replicated on the HMD. The HMD layout essentially replicates the

HUD layout. Window locations, format, and occlusion level on the HMD are as identical to the HUD

locations, format, and occlusion level as practical.

2.23.12.6 HUD Symbology Not Replicated on the HMD. Some of the symbology on the HUD is

either not required on the HMD or would be disorienting if the information was presented. The

following paragraphs describe the items on the HUD which are not replicated on the HMD.

2.23.12.7 Aircraft Attitude Data. Some HUD data only provides the pilot usable information when

presented along the aircraft boresight. HMD data is not always presented along the aircraft boresight.

For this reason, the aircraft pitch ladder, horizon bar, water line indicator, and velocity vector are not

displayed on the HMD/AHMD.

The HMD/AHMD does not provide adequate attitude information and

should not be used as a primary flight instrument.

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2.23.12.8 Ground Proximity Warning System. In addition to aircraft attitude data, the HMD/

AHMD does not replicate the Ground Proximity Warning System (GPWS) arrow. However, when the

GPWS is activated, ALTITUDE is displayed in the HARM window of the HMD/AHMD.

2.23.13 Navigation Master Mode. If present, the MC displays the A/A L&S with the TD box and its

associated TLL, or the A/G designation with the TD diamond and its associated TLL. However, if both

the A/A L&S and the A/G designation are present, only the A/A L&S TLL is displayed.

2.23.13.1 NAV Master Mode TDC Priority. When in NAV master mode, the TDC/DC can be

assigned priority to the HMD/AHMD by pressing the castle switch or DCA forward. This is indicated

by the display of an open aiming cross with a dot in the center. If TDC/DC priority is removed from

the HMD/AHMD, the dot is removed from the center of the aiming cross.

2.23.14 Mission Computer Failure. If either MC fails, no symbology is displayed on either helmet

and the remaining operating MC functions as if no helmets are installed.

2.23.15 Electronic Unit Failure. In the event of an EU failure which does not allow any symbology

to be displayed on the HMD, the MC provides the radar boresight symbol and AIM-9 FOV symbol on

the HUD. If the LOS is still valid, the MC continues to slave the radar or AIM-9 to the HMD LOS. If

the LOS is invalid, the MC reverts to the current no-helmet mechanization for slaving weapons,

sensors, and HOTAS.

2.23.16 Helmet Tracker Failure. If the EU reports that the helmet tracker is failed, or the helmet

LOS is no longer valid, the MC discontinues slaving sensors and weapons to the HMD LOS. The MC

replaces aircraft boresight for the helmet LOS to the radar and AIM-9. Additionally, the MC removes

any item from the HMD which is tied to the HMD LOS. The radar boresight and AIM-9 FOV symbol

are restored to the HUD. The MC also restores VACQ mode and the HOTAS function to access the

VACQ function. The MC continues to display information on the HMD which is not tied to the HMD

LOS.

If the EU reports the aft helmet tracker is failed or the aft helmet LOS is no longer valid, the MC

discontinues slaving sensors and weapons to the aft HMD LOS and reverts to non-helmet mechani-

zation in the aft cockpit. Additionally, the MC removes any item from the aft HMD that is tied to the

aft HMD LOS and continues to display information on the aft HMD that is not tied to the aft HMD

LOS.

2.23.17 Helmet Not Installed. When the MC determines that the HMD is not on, or the EU is not

responding to the MC via the mux bus, the MC reverts to the current no-helmet mechanization for

slaving weapons, sensors, HOTAS, and HUD display.

When the MC determines that the AHMD is not on, the MC reverts to the current aft seat

mechanization for slaving weapons and sensors, and HOTAS. If the forward HMD is installed and

operating the forward helmet functions as described in previous paragraphs. If the EU is not

communicating, both cockpits revert to no helmet status.

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EA-18G. FLIGHT MANUAL (2008) - page 4