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EA-18G. FLIGHT MANUAL (2008) - page 2

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Figure 2-1. Throttle Grips (Front Cockpit)

On battery power prior to APU start, the EFD displays only RPM and TEMP (figure 2-2). When the

APU switch is selected ON, the entire top level format is displayed but only RPM, TEMP, and OIL

pressure are valid. When the first engine alternator comes online at 10% N₂ rpm, the FF parameter

also becomes valid. When the first generator comes online at 60% N₂ rpm, all parameters for both

engines become valid. If the EFD locks up or blanks completely during engine start power transients,

the display can be reset by selecting the SDC RESET option from the SUPT MENU/FUEL display.

The EFD displays the following engine parameters within the listed display tolerances:

RPM Compressor rpm (N₂ ) (0 to 127%) - Displays RPM in inverse video format above

102%

TEMP Compensated turbine exhaust gas temperature (EGT) (186 to 1,088°C) - Displays 9999

in inverse video above 1,100°C

FF

Total commanded fuel flow including afterburner (0 or 400 to 65,000 pph in 100 pph

increments).

NOTE

Engine fuel flow is calculated from commanded engine fuel metering

valve position. In failure modes, fuel flow can be indicated on the EFD

even though no actual fuel is flowing.

OIL

Oil pressure (0 to 200 psi)

NOZ VEN position (0 to 101% open)

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Figure 2-2. Engine Fuel Display (EFD) - Engine Parameters

During first engine battery start, the EFD RPM indication typically jumps from 0 to either 5% or

10%, and lightoff is indicated by TEMP rising from a minimum reported value of approximately

190°C. Each engine has three sources of N₂ rpm: two engine alternator sensors and one accessory

gearbox sensor. The accessory gearbox sensor can provide rpm readings down to only 5% and is the

initial source of engine RPM. Readings from the alternator sensors are not available until the

alternator comes online above 10% N₂ rpm. Input for the TEMP parameter is provided by a

compensated EGT algorithm in the FADEC. When actual EGT is below accuracy tolerances (e.g.,

engine shutdown), the FADEC limits the minimum reported TEMP (approximately 190°C). The FF

parameter is a calculated number based on metering valve position, not an actual measurement of fuel

flow. Consequently, an indication of fuel flow may be present when there is no flow, such as when the

throttle is above IDLE with the engine off.

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Figure 2-3. Engine Display

The selected fuel grade is displayed top center and also on the takeoff side of the CHKLIST display.

The FUEL option enables the JP-5, 8, and JP-4 options, each of which must be selected twice to change

the fuel grade. The fuel grade selected should reflect the majority of fuel in the aircraft. JP-5, -8 should

be selected when using JET-A, A+, or A1. The engines can be started and operated at ground idle with

either fuel grade selected; however, for operations above IDLE, the correct fuel grade must be selected

to ensure proper engine operation and to avoid engine combustor rumble. The fuel grade selected is

also used by the FADEC to control the thermal control valve (TCV) setting and determines the

maximum fuel temperature to be sent to the engines. Incorrect fuel grade selection can adversely

impact the fuel thermal management system and result in a premature FUEL HOT caution. The

RECORD option, boxed when selected, saves a 30 second record of display and engine data (15 seconds

pre- and 15 seconds post-event) to the memory unit (MU). The DFIRS DWNLD option downloads

DFIRS data to the MU.

2.1.2 Automatic Throttle Control (ATC). The ATC system has two operating modes: approach and

cruise. The system automatically modulates engine thrust between flight IDLE and MIL power in

order to maintain on-speed angle of attack (AOA) in the approach mode or calibrated airspeed

(existing at the time of engagement) in the cruise mode.

During ATC operation, engine commands are sent to the FADEC directly from the FCCs instead of

the throttles. FCC generated engine commands are limited to a range slightly above idle to slightly

below MIL. The throttles are continuously positioned by an FCC commanded backdrive unit to match

the throttles with the current engine command and to provide feedback to the pilot.

2.1.2.1

ATC Engagement. Pressing and releasing the ATC button on the left throttle engages the

approach mode with the FLAP switch in HALF or FULL and the cruise mode with the FLAP switch

in AUTO. When either mode is engaged, an ATC advisory is displayed on the HUD. Because ATC

mode engagement and ATC HUD advisories are not commanded until release of the ATC button, the

pilot may need to deliberately pause after press and release to avoid inadvertant ATC disengagement/

re-engagement. Automatic transition between the two modes or engagement during single engine

operation is not possible. Engaging ATC with the friction lever in the full aft position and with the

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Figure 2-4. Tank 1 and 4 Fuel CG Control and FUEL XFER Caution Schedule

transfer from the lower tank by closing its wing motive flow control valve. If wing tank asymmetry

exceeds 350 lb for 15 seconds, the FUEL XFER caution appears.

Wing tank balancing also occurs during refueling, where the SDC alternately opens/closes the wing

refuel valves attempting to keep the wing tanks within 200 lb. The FUEL XFER caution is not set

during refueling. If SDC balancing logic cannot keep the wings from refueling asymmetrically (greater

than 350 lb), the FUEL XFER caution is set when the inflight refueling probe is retracted.

2.2.2.2.2

INTR WING Control Switch. The INTR WING control switch, located on the EXT LT

panel on the left console, is used to isolate the wing tanks (e.g., following battle damage).

INHIBIT Prevents normal transfer and refueling of the wing tanks (closes both wing motive

control valves, both wing refuel valves, and switches both diverter valves, located

in Tank 3, from the wing tanks to the feed tanks).

NORM

Permits normal transfer and refueling of the internal wing tanks.

2.2.2.3

External Fuel Transfer. External fuel is transferred by regulated engine bleed air pressure

applied to all installed external tanks with WoffW. External tank pressurization is terminated for

inflight refueling (PROBE switch in EXTEND) and for arrested landing (both HOOK and LDG

GEAR handles down). With pressurization applied, external fuel transfer is controlled by the three

EXT TANKS transfer switches.

During external transfer, fuel is routed through the aircraft’s refuel/defuel line. Refuel valves in each

tank open only if commanded by the SDC and space is available. At MIL power and below, the SDC

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Figure 2-5. Fuel Quantity

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Figure 2-6. Engine Fuel Display (EFD) - Fuel Parameters

2.2.7.1

Engine Fuel Display (EFD), Fuel Parameters. The EFD displays fuel, maintenance code, and

consumables information in green digits on a black background (figure 2-6). The front EFD is

independent of the rear EFD. The top level EFD format graphically displays total internal fuel, bingo

level, and fuel quantities for up to five external fuel tanks. The shaded regions of each graphic display

the ratio of fuel available to fuel capacity. Digital readouts of total fuel (large numbers), total INT fuel,

external fuel tank quantities, and current BINGO setting are also provided but are truncated to 100 lb

increments.

The internal fuel format graphically displays only internal fuel tank quantities. Digital readouts of

feed tank fuel quantities are also provided, truncated to 100 lb increments.

During battery start of the engines, the EFD defaults to display three external fuel tanks (centerline

and inboard pylons) if one or more external fuel tanks are installed. For instance, if a full centerline

tank is installed, the EFD displays a full centerline graphic and 3.2 lb fuel. The inboard tanks appear

empty reading 0.0 lb fuel. When the SMS completes startup BIT and initial inventory, the EFD

displays only the installed tank(s).

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Figure 2-7. FUEL Display

b. TOTAL fuel is estimated by the MC based on the last valid fuel quantity and engine fuel flow.

c. A flashing ESTIMATED cue is displayed along with a minutes and seconds (XX:XX) timer

which indicates the duration since the displayed fuel quantities were last updated.

2.2.8 Fuel Low Level Indicating System. The fuel low level indicating system is completely

independent of the fuel quantity indicating system. When the fuel level in either feed tank drops to

approximately 1,125 lb, a FUEL LO caution, caution light, and voice alert are activated, and the

affected fuel tank quantity is displayed in inverse video on the EFD. If a low level indication was set

by a transient condition, such as prolonged negative g flight, the cautions remain on for 1 minute after

the low level indication is removed.

If the FUEL LO cautions are set, assume that at least one feed tank is

below approximately 1,125

lb regardless of displayed fuel quantity

indications.

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Figure 2-8. FPAS Displays

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Figure 2-9. Secondary Power Supply

2.4 SECONDARY POWER SYSTEM

The aircraft secondary power system contains two airframe mounted accessory drives (AMAD) and

a single auxiliary power unit (APU). Figure 2-9 shows the major components of the secondary power

system.

2.4.1 Airframe Mounted Accessory Drive (AMAD). During normal operation, each AMAD is

mechanically driven by its corresponding engine through a power transmission shaft and is used to

drive a fuel boost/motive flow pump, an ac/dc electrical generator, and a 3000/5000 psi hydraulic pump.

Pneumatic pressure is used to rotate an air turbine starter (ATS) on each AMAD for engine crank/start

capability.

For ground maintenance use, either AMAD can be decoupled from its engine, allowing pneumatic

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Figure 2-10. Simplified Electrical Schematic

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determine whether an EBB PMG or the battery is powering the essential bus following a dual GEN

failure. These cautions are set in only two circumstances.

1. The BATT switch is ON on the ground in the absence of ac power (e.g., first engine start). The

battery is depleting and the switch should be placed to OFF unless APU start is about to be made.

2. The BATT switch is OFF inflight and should be placed to ON to provide essential bus backup

capability from the PMGs and the battery.

2.5.4 External Electrical Power. External electrical power may be connected to the aircraft bus

system through an external power receptacle located on the left forward fuselage. If external power is

not of the proper quality, the external power monitor prevents application of power to the aircraft.

Actuation of 1 to 4 ground power switches is required to energize certain aircraft systems following

application of external power.

The aircraft buses are energized by external power in the same manner as if a generator were

operating provided the BATT switch is OFF or the parking brake is set.

2.5.4.1

External Power Switch. The external power switch, located on the ground power panel on the

left console, is spring loaded to the NORM position (figure 2-12).

Figure 2-11. FCC Electrical Redundancy

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Figure 2-12. Ground Power Panel and Placard

RESET

Momentary actuation allows external power to be applied.

NORM

Aircraft buses are energized by external power, provided the switch was first posi-

tioned to RESET. The switch returns to OFF when external power is disconnected.

OFF

Disconnects external power from the aircraft.

2.5.4.2

Ground Power Switches. The four ground power switches are located on the ground power

panel on the left console (figure 2-12). Each switch controls a group of systems and/or instruments, as

listed on a placard above the panel.

A ON

Only systems/instruments listed for the A position are energized by external

power.

AUTO

All controlled systems/instruments are deenergized with external power on the air-

craft. When a generator comes online, the switch(es) automatically revert to

AUTO.

B ON

All controlled systems/instruments (both A and B) are energized by external

power.

The first ground power switch placed to ON must be held for 3 seconds to complete an avionics

overheat BIT. If an avionics overheat condition is present, the switch(es) revert to AUTO and cannot

be returned to ON until the condition is corrected.

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Figure 2-13. Circuit Breaker Panels

2.5.5 Circuit Breakers. The circuit breaker panels (figure 2-13), located under each side of the

canopy sill outboard of the left and right consoles, contain the following circuit breakers:

Left Side

Right Side

LAUNCH BAR

FCS CHAN 3

FCS CHAN 2

FCS CHAN 4

FCS CHAN 1

HOOK

LG

2.5.6 Electrical System Cautions and Caution Lights. The following electrical system cautions and

caution lights are described in the Warning/Caution/Advisory Displays in Part V:

• L or R GEN caution and caution light

• BATT SW caution and caution light

• GEN TIE caution light

• L or R DC FAIL caution

2.6

LIGHTING

2.6.1 Exterior Lighting. Exterior lighting is utilized to highlight aircraft position and aspect to other

aircraft, to provide AOA indications to a landing signal officer (LSO), to light the aircraft path for

in-flight refueling, landing or taxi, and to distinguish the EA-18G from other F/A-18 models. The

following exterior lights are provided: strobe lights, position lights, formation lights, approach lights,

refueling probe light, and landing/taxi light (figure 2-14).

Strobe lights and formation lights have two operating modes, normal and NVIS.

2.6.1.1

Exterior Lights Master Switch. The exterior lights master switch, located on the outboard

side of the left throttle grip, provides master control of all exterior lighting except the approach and

landing/taxi lights.

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Figure 2-14. Exterior Lights

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the wingtip, one on the LEX just forward of the wing root and one under the wing at the aileron hinge.

Green position lights are installed at the same locations on the right side.

2.6.1.3.1

POSITION Lights Knob. The POSITION lights knob, located on the EXT LT panel on the

left console, is used to apply power and control the brightness of the position lights (external lights

master switch NORM). The knob provides variable lighting intensity between the OFF and BRT

positions.

2.6.1.4

Formation Lights. Ten formation ″strip″ lights, five on each side of the aircraft, are provided

to highlight the aircraft aspect during night or low visibility formation flight. Strip lights are located

on the forward fuselage forward of the LEX, on the wingtip upper and lower surfaces of the

ALQ-218(V)2 wingtip pods, on the aft fuselage below the vertical tail, and on the vertical tail. Each

formation light contains two lighting strips, one normal and one IR. The external lights master switch

determines which set of strips are powered by the FORMATION lights knob.

2.6.1.4.1

FORMATION Lights Knob. The FORMATION lights knob, located on the EXT LT panel

on the left console, is used to apply power and control the brightness of the formation strip lights. The

knob provides variable lighting intensity between the OFF and BRT positions in either the normal or

NVIS mode.

2.6.1.5

Approach Lights. The approach lights, located on the nosegear strut, provide AOA indica-

tions to an LSO during carrier landings. Three approach lights are provided to indicate a fast (red),

on-speed (amber), or slow (green) AOA condition. The approach lights are powered with WoffW and

all landing gear down and locked. Therefore, the approach lights are an external indication that the

Figure 2-15. ID Strobe Patterns

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Figure 2-16. Hydraulic Flow

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Figure 2-17. Wheel Brake and Anti-skid System

Failure of either wheel speed sensor can lead to an anti−skid failure,

resulting in a complete loss of brakes. Placing the ANTI SKID switch to

the OFF position or pulling the EMERG BRK handle will bypass the

faulty system and restore braking ability. Judicious braking must be

used, as the anti−skid system is not available. Refer to the BRAKES

FAILURE/EMERGENCY BRAKES procedure.

The system contains two wheel speed sensors, an anti-skid control unit, and an anti-skid control

valve. The anti-skid control unit senses wheel speed and operates by electronically limiting the amount

of HYD 2A pressure that is applied to the wheel brakes through the anti-skid control valve and the

normal brake lines. Anti-skid is not available when emergency brakes are selected.

Touchdown protection delays initial brake application on landing by completely dumping brake

pressure until (1) weight is on the right main landing gear and wheel speed is over 50 knots or (2), if

a wet runway delays wheel spin-up, for 3 seconds after landing. This function prevents landing with

locked main wheels (tire blowouts) even if full brake pedal force is applied at touchdown.

Wheel spin-up override is activated at 50 knots wheel speed to allow normal braking if the right

WonW switch fails.

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Figure 2-18. Emergency/Parking Brake Handle

• Do not cycle the ANTI SKID switch in response to an ANTISKID

caution immediately prior to landing. Cycling the ANTI SKID switch

removes the ANTISKID caution for up to 13.5 seconds as the system

performs IBIT even though the anti-skid system may still be failed

and, if the system is not failed, wheel motion at touchdown may cause

a false BIT failure and a dump of normal brake pressure when brakes

are applied.

• If the ANTI SKID switch is not placed to OFF with an ANTISKID

caution displayed, normal braking capability may be lost completely.

2.8.3.5

Emergency Braking. Emergency braking is enabled when the EMERG BRK handle is pulled

to detent. This action opens the emergency brake valve and applies backup hydraulic pressure to the

hydraulic servovalves. If available, backup pressure from HYD 2B is utilized through the aft isolation

and arming valves, which are open with WonW. If HYD 2 is failed completely, backup pressure from

both the brake and APU accumulators is used. Check valves are incorporated to prevent the loss of

accumulator pressure if HYD 2B is failed. With backup pressure applied, the servovalves isolate HYD

2A pressure, if still available, so that the normal brake lines are unpressurized.

During emergency braking, backup pressure is applied through the left and right servovalves

proportional to the amount of pilot applied brake pedal force and is routed to the main wheel brakes

through the emergency brake lines. These lines bypass the anti-skid control valve, so the pilot must

regulate brake pedal force to prevent wheel skid.

Hydraulic accumulators and the brake accumulator pressure gauge are discussed in the Hydraulic

Power Supply System section.

2.8.3.5.1

EMERG BRK Handle. The EMERG BRK handle is combined with the PARK BRK handle

and is located on the lower left main instrument panel in the front cockpit. When the handle is in the

stowed, emergency position (horizontal), the ‘‘EMERG’’ label appears upright. See figure 2-18. To

select emergency brakes, the handle must be pulled to the detent while in the horizontal position.

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Figure 2-20. Flight Control System Functional Diagram

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characteristics, and to provide load alleviation (when required). In general, LEFs start to deflect as

AOA increases above approximately 3°, reaching full deflection (34° LED) by about 25° AOA. In

general, TEFs start to deflect above 2 to 3° AOA, are at full scheduled deflection (approximately 10 to

12° TED) from approximately 6 to 15° AOA, and begin to retract as AOA increases further. In other

words, TEFs are deflected in the heart of the maneuvering envelope to produce more lift and are

retracted at high AOA. With flaps AUTO, aileron droop is scheduled to 50% of TEF deflection at low

AOA and to 0° at high AOA.

With flaps AUTO, flap scheduling is altered slightly based on the presence of a wing tank on station

4 or 8. With at least one wing tank installed on station 4 or 8, TEF deflection is slightly lower at most

flight conditions. LEFs and TEFs typically begin to deflect at slightly slower Mach but follow the same

trends as those mentioned above.

With flaps HALF or FULL, LEFs are scheduled as a function of AOA to maximize lift. TEFs are

scheduled as a function of airspeed for load alleviation but should be at maximum scheduled deflection

at approach speed. With flaps HALF or FULL, aileron droop is scheduled with TEF deflection.

Following field takeoff or catapult launch, TEF/aileron droop is latched for 10 seconds after the

transition to WoffW. This feature is designed to improve catapult launch characteristics by ensuring

the flaps do not retract immediately after launch. However, if approximately 190 KCAS is exceeded

prior to expiration of the 10 second timer, the TEFs and aileron droop do begin to retract for loads

alleviation. LEF, TEF, and aileron droop scheduling are shown in figure 2-21.

FLAPS

Configuration

Status

LEF Position TEF Position AIL Droop

WonW

3° LED

2° TED

1° TED

50% of TEF

Scheduled

No Wing Tanks

Scheduled

(<10° AOA),

WoffW

with M, AOA,

with M, AOA

0°

Alt

(>15° AOA)

AUTO

WonW

3° LED

4° TED

2° TED

50% of TEF

Scheduled

Wing Tanks

Scheduled

(<10° AOA),

WoffW

with M, AOA,

with M, AOA

0°

Alt

(>15° AOA)

WonW

15° LED

30° TED

30° TED

Flaps HALF

Scheduled

30° TED

30° TED

WoffW

HALF or

with AOA

(on-speed)

(on-speed)

FULL

WonW

15° LED

40° TED

40° TED

Flaps FULL

Scheduled

40° TED

40° TED

WoffW

with AOA

(on-speed)

(on-speed)

Figure 2-21. Flap Schedules

2.10.6 Speedbrake Function. The aircraft is not fitted with independent speedbrake surfaces. A

″speedbrake function″ is provided to increase drag by partial deflection of several of the aircraft’s

primary flight control surfaces: ailerons, rudders, TEFs, and spoilers. The stabilators are commanded

to counter pitch transients during speedbrake extension and retraction. The full speedbrake function

can only be commanded with flaps AUTO.

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Figure 2-22. G-Limiter G-Bucket Reductions in Maximum Commandable G-Level

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Displacement Force

Flight Control

Direction

(in)

(lbs)

Forward

2.5

20

Stick

Aft

5.0

37

Left/Right

3.0

13

Pedal

Left/Right

1.0

100

Figure 2-23. Stick and Pedal Travel Limits

2.10.9.2 Rudder Pedals. Two rudder pedals (left and right) are used to provide directional inputs to

the FCS for yaw/roll control inflight or NWS control with WonW. Since there is no mechanical linkage

between the rudder pedals and the FCCs or the flight control surfaces, rudder pedal feel is provided

by two feel-spring assemblies. The feel spring assemblies provide a linear pedal force versus

displacement gradient. Two 4-channel position sensors, one on each pedal, measure pedal displace-

ment and send directional commands to the FCCs proportional to pedal displacement. Rudder force

and displacement are listed in figure 2-23 for full pedal travel. The rudder pedals are also used to

provide NWS commands and to actuate toe-operated wheel brakes.

2.10.9.2.1 RUD PED ADJ Lever. A RUD PED ADJ lever, located on the center pedestal in each

cockpit, is spring loaded to the up and locked position. When the lever is held down, the rudder pedals

are unlocked and can be moved forward and aft in ½ inch increments. Both pedals are spring loaded

to move aft and must be pushed forward to the desired position. Releasing the RUD PED ADJ lever

locks the pedals in the new position.

• Restrain the rudder pedals during adjustment. Unrestrained rudder

pedals may damage the rudder pedal mechanism.

• Ensure the rudder pedals are locked in position after adjustment.

Failure to lock the rudder pedals may result in uncommanded forward

rudder pedal movement inflight.

2.10.9.3 Stick Grip FCS Controls. The FCS controls located on the stick grip include the pitch and

roll trim switch, the NWS button, and the autopilot/NWS disengage switch. See figure 2-24.

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2.10.9.3.1 Pitch and Roll Trim Switch. The pitch and roll trim switch is located on the top right of

the stick grip. Movement of the pitch and roll trim switch electrically biases the FCCs and does not

reposition the stick.

Forward

Trims nose-down.

Aft

Trims nose-up.

Left

Trims left-wing-down.

Right

Trims right-wing-down.

Pitch and roll trim inputs can be made incrementally or held for faster trim rates. With flaps AUTO,

little if any pitch trim is required due to the automatic trimming function provided by P CAS. With

flaps HALF or FULL, pitch trim is required to trim for on-speed AOA. Lateral trim is typically only

required immediately after takeoff or following changes in lateral weight asymmetry (fuel and/or

stores). Pitch trim is not monitored for runaway trim. However, roll trim is monitored for a stuck

switch. If the trim switch is held or is stuck in the left or right position for more than 40 seconds, the

FCS caution is set and the roll trim function of the switch is disabled for the remainder of the flight.

Roll trim can be faded to zero by pushing and holding the FCS RESET button or TO/TRIM button

for approximately 4 seconds.

Figure 2-24. Stick Grip FCS Controls

2.10.9.3.2 NWS Button. The undesignate/nosewheel steering button is located on the front of the

stick grip. The NWS button is used to engage NWS modes, as described in the NWS System

paragraphs in the Utility Hydraulic Functions section. The undesignate function of the NWS button

is described in the Weapon Systems Controls section.

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Figure 2-25. SPIN Recovery Display

commanding a high AOA roll (e.g., pirouette) the yaw rate threshold persistence is increased from 15

seconds to 25 seconds.

Immediately following a low-speed maneuver less than 77 KCAS (e.g., tail-slide), airspeed limits for

SPIN logic are opened to 180 KCAS or 12 seconds, whichever comes first. During this time, the normal

acceleration feedback gain is removed to avoid excess coupling, and spin mode arrows will be displayed

to aid recovery if yaw rate exceeds the threshold.

Once a spin has been detected, the spin recovery system places the SPIN MODE recovery displays

on both DDIs (figure 2-25), illuminates the amber FLAPS light, and drives the LEFs to 34° LED and

the TEFs to 4° TED. The displayed spin recovery arrow always indicates the proper direction for

anti-spin lateral stick inputs whether the spin is upright or inverted. Anti-spin lateral stick inputs are

aileron-into for upright spins and aileron-opposite for inverted spins. When lateral stick is placed with

the arrow, automatic spin recovery mode (ASRM) is engaged. With ASRM engaged, all CAS feedback

and control surface interconnects are removed, providing full aileron, rudder, and stabilator authority

for spin recovery. If the stick is neutral or is moved in the wrong direction, the SPIN MODE formats

remain displayed, the LEFs and TEFs remain deflected, but the FCS remains in CAS, and ASRM is

not engaged.

If ASRM is engaged during spin recovery, the spin arrow is removed and the FCS automatically

reverts to CAS when either of the following conditions are met: (1) airspeed is above approximately 245

KCAS or (2) the yaw rate threshold is no longer exceeded. After recovery, LEFs and TEFs return to

normal scheduling, and the SPIN MODE formats are replaced with the MENU page after 2 seconds.

NOTE

During highly oscillatory spins or spins that transition from upright to

inverted or from inverted to upright, the SPIN MODE displays may

disappear momentarily.

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