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F16C/D. FLIGHT MANUAL (2002) - page 23

T.O. GR1F16CJ1

369

The first indication of an engine stall at high thrust

settings may be a loud bang or pop. At lower thrust

settings, the first indication may be loss of thrust,

lack of throttle response, or decreasing engine rpm.

When a stall is sensed, the DEEC cancels the AB (if

throttle is in AB range), opens the nozzle, and

decreases fuel flow until the stall clears. FTIT and

NOZ POS may fluctuate in response to the stall

recovery signal. If the engine auto transfers to SEC,

automatic stall recovery and overtemp protection are

not available. A malfunction such as engine internal

damage or primary control system failure could result

in a stall, an automatic SEC transfer, and possible

FTIT overtemp. Throttle reduction is appropriate as

a first response to clear any engine stall.

If the engine stalls at low altitude, an immediate

climb should be initiated, and stores jettison should

be considered. Retarding the throttle may clear the

stall. During a high thrust stall that is self recovering,

there will be an immediate thrust loss. In PRI, the

DEEC gradually restores thrust to the original level.

If engine response at low altitude is not sufficient to

maintain or gain altitude and a suitable landing field

is not available, ejection may be required.

If a stall occurs at MIL or below, retarding the throttle

may clear the stall. Further throttle movement

should be limited to midrange or below.

ABAssociated Engine Stalls

PW 229

ABassociated stalls are normally accompanied by a

loud bang or pop and a series of fireballs from the

engine exhaust and occasionally the engine inlet. This

is followed by an erratic flame from the engine exhaust

if the stall is nonrecoverable. These characteristics

could be mistaken for an aircraft fire. Whenever a stall

occurs while operating in AB, the DEEC automatically

cancels AB and activates stall recovery. This may be

accompanied by a nozzle swing to full open for a few

seconds and an associated temporary reduction of

thrust. The throttle should be snapped out of AB to

MIL. This action usually clears the stall and restores

normal operation; however, stalls may continue at MIL

and can be severe. They may be characterized by bangs

or pops of low intensity or engine vibrations severe

enough to preclude reading engine instruments. Refer

to NONAB ENGINE STALLS

PW 229

, this section.

NonAB Engine Stalls

PW 229

NonAB stalls may occur if the engine is malfunction

ing, particularly during throttle transients near

IDLE. NonAB stalls are often a symptom of a serious

engine problem. NonAB stalls may be inaudible; the

first indication may be a lack of throttle response

which may be difficult to differentiate from abnormal

engine response. However, nonAB stalls can also be

severe. They may be characterized by bangs, pops,

low intensity or severe engine rumble or vibration. A

momentary nozzle swing to near full open may occur,

causing a temporary reduction in thrust, as the

DEEC activates stall recovery. An erratic orangeyel

low flame from the engine exhaust may be present.

This exhaust flame should not be mistaken for an

engine fire. If the stall is confirmed, the throttle

should be immediately retarded to IDLE which may

clear the stall. Further throttle movement should be

limited to midrange or below.

Prolonged engine operation with FTIT

in excess of 1000

C can result in

significant engine damage and may

cause a nonrecoverable engine failure.

Engine Stall Recovery

PW 229

If an AB stall(s) occurs:

Throttle-Snap to MIL.

If AB stalls do not clear or stall(s) occurs below AB:

NOTE

NonAB stalls may be inaudible.

Throttle-IDLE.

ANTI ICE switch-OFF when conditions

permit.

NOTE

Stalls may be caused by antiice valve

failing to close at high thrust setting

(throttle above midrange).

If stalls continue at idle and engine rpm is less than 60

percent with no rpm response to throttle movement:

Throttle-OFF. Initiate airstart. Refer to AIR

START PROCEDURES

PW 229

, this section.

Shutting down the engine with an

engine alternator failure (indicated by

zero or erroneously low rpm, illuminated

SEC caution light, illuminated ENGINE

warning light, and normal thrust)

results in no ignition for an airstart.

T.O. GR1F16CJ1

370

If nonAB stall(s) clears:

Throttle-Midrange or below.

If a nonAB stall clears, maintain throttle at

midrange or below unless required to sustain

flight.

Land as soon as possible.

If AB stall(s) clears:

Throttle-As required.

If an AB stall clears, the engine is safe to

operate in the IDLE to MIL range, provided

no other abnormal indication is observed.

Attempt further AB operation only if needed

to sustain flight.

INLET BUZZ

PW 229

Inlet buzz occurs at supersonic airspeeds if the engine

control system fails to maintain adequate engine rpm

when the throttle is retarded below MIL. Inlet buzz

causes moderate to severe vibration within the

cockpit and probably results in multiple engine stalls.

If inlet buzz occurs, do not move the throttle until

subsonic. Decrease airspeed to subsonic as quickly as

possible by opening the speedbrakes and increasing g.

If engine stalls occur and persist, the throttle should

be retarded to IDLE when subsonic. If the stalls do not

clear, the engine must be shut down and restarted.

ENGINE FAILURE OR FLAMEOUT

PW 229

Engine failures can result in rpm decrease with no

abnormal vibration or sound (flameout), rpm

decrease with abnormal vibration and/or stalls, or

stable rpm with abnormal vibration and/or low

thrust.

If the engine flames out, fuel starvation or

mechanical failure has occurred. A flameout is

indicated by decrease in FTIT and engine rpm

decaying below approximately 60 percent. Loss of

thrust and lack of response to throttle movement

confirm the flameout. The ENGINE warning light

illuminates when engine rpm is below 55 percent.

Additionally, the MAIN GEN and STBY GEN lights

illuminate below 45 percent rpm and the EPU should

start running. Do not mistake a loss of ECS noise as

an engine flameout.

If the reservoir tanks do not contain fuel, an airstart

is impossible. If fuel starvation was due to a

temporary lack of fuel, restart should be possible. If

fuel quantities appear normal, the flameout may

have been caused by fuel contamination. In this case,

placing the throttle to OFF may clear the

contaminated fuel and allow an airstart.

Main fuel pump failure or tower shaft geartrain

failure also causes flameout. Both present similar

symptoms:an abrupt decrease of indicated fuel flow

to less than 500 pph; loss of main generator, standby

generator, and FLCS PMG and EPU activation; no

throttle response; and illumination of the SEC

caution light even though the ENG CONT switch is in

PRI,

NORM.

If only the main fuel pump has failed, the rpm

indication reflects a gradual spooldown. The JFS can

be started and the engine can be motored at

approximately 25 percent rpm. If the SEC caution

light remains on (with ENG CONT switch in

PRI,

NORM and engine rpm at 12 percent or

above), the engine probably cannot be restarted;

therefore, place primary emphasis on a flameout

landing while continuing airstart attempts. If unable

to make a flameout landing, refer to EJECTION, this

section.

Tower Shaft Failure

PW 229

Failure of the engine tower shaft or its associated

geartrain results in loss of all rotation to the engine

gearbox and the ADG. Loss of rotation to the engine

gearbox renders the engine alternator, main fuel pump,

and oil pump inoperative resulting in a zero rpm

indication, zero oil pressure, illumination of the

ENGINE warning and SEC caution lights, and engine

flameout due to fuel starvation. The initial symptoms

are similar to main fuel pump failure; however, the

primary difference is that the rpm and oil pressure

indications drop immediately to zero with a tower shaft

failure since the engine alternator is not being driven.

Additional symptoms caused by loss of rotation to the

ADG include loss of hydraulic systems A and B, main

and standby generators, and FLCS PMG and

subsequent activation of the EPU. It may be possible to

regain engine operation using the JFS and performing

an SEC airstart. The JFS drives the ADG and the

engine gearbox (through the PTO shaft), restoring

rotation to both hydraulic pumps, FLCS PMG (at a

reduced output), main fuel pump (SEC caution light

goes off in PRI until SEC is selected), engine alternator

(cockpit rpm signal, DEEC power, and engine ignition),

and oil pump (oil pressure increases). Without the load

of the engine, the JFS produces an rpm indication

fluctuating between 3050 percent which is the speed of

the engine alternator, not the actual engine rpm. This

rpm may be high enough to restore standby generator

power; however, main generator power may cycle on

and off line with the rpm fluctuations. If the ENG

CONT switch is still in

PRI,

NORM, the SEC

caution light goes off when fuel pump pressure is

restored; however, a PRI airstart is not possible since

T.O. GR1F16CJ1

Change 1371

the rpm signal to the DEEC is in error. Perform an

SEC airstart. Since the JFS is not preserving rpm,

maintain 250 knots minimum during the airstart

attempt, which should assure adequate actual engine

rpm for the airstart.

Low Altitude Engine Failure or Flameout

PW 229

Refer to figures 37 and 38. Initial reaction to any

malfunction at low altitude should be to trade excess

airspeed for altitude. Higher altitude translates

directly to either additional time to achieve an

airstart or to additional glide range to reach a suitable

landing field. At low airspeed, the climb may be only

enough to insure a safe ejection altitude. Above 350

knots, more time is available by a zoom climb using

a 3g pullup to 30degree climb approaching the

desired airspeed (use approximately 50 knots lead

point) and then initiating a zero g pushover. Below

350 knots and above the minimum recommended

ejection altitude, more time is available by perform

ing a constant altitude deceleration to the desired

airspeed. If below the minimum recommended

ejection altitude and below 350 knots, primary

concern should be to trade excess airspeed for altitude

in preparation for ejection.

If required, jettison stores as soon as possible to aid in

gaining or maintaining altitude and maneuver

toward a suitable landing field, if available. If the

zoom results in an altitude below 4000 feet AGL,

there will probably be insufficient time to achieve an

airstart prior to minimum recommended ejection

altitude. In that case, primary consideration should

be given to preparing for ejection; do not delay

ejection below 2000 feet AGL. If the zoom results in

an altitude between 400010,000 feet AGL, there is

probably time for one airstart attempt prior to

minimum recommended ejection altitude. This

attempt shall be performed in the control mode

selected by the DEEC.

If low altitude engine failure or flameout occurs:

Zoom.

Stores-Jettison (if required).

If stores jettison is attempted after main and

standby generators drop off line but before

EPU generator powers the SMS (approxi

mately 5 seconds delay), stores will not

jettison.

NOTE

Visually confirm the stores have jetti

soned and jettison again if required.

Perform airstart (if altitude permits). Refer to

AIRSTART PROCEDURES

PW 229

, this section.

Below 4000 feet AGL, there may be

insufficient time to perform an airstart

prior to minimum recommended ejec

tion altitude.

AIRSTARTS

PW 229

Refer to figure 39. Factors such as altitude, airspeed,

weather, etc., must be considered in determining

whether to try an airstart, accomplish a flameout

landing, or eject. Jettisoning of stores reduces

altitude loss during an airstart and improves glide

ratio during a flameout landing.

Oil pressure is directly related to rpm. Do not confuse

a low oil pressure indication due to windmilling rpm

as an oil system malfunction.

If the engine seized due to an oil system malfunction

or flamed out due to total fuel starvation or

mechanical failure, either a flameout landing or

ejection is required.

The most likely reason to perform an airstart is that

the engine has shut down due to a PRI system failure

or hardware failure or to clear a stall. The DEEC

assesses any faults or internal failures and

automatically transfers to SEC, if required. The first

airstart attempt should be made in the engine control

mode selected by the DEEC

except when a tower shaft

failure is suspected it shall be performed in SEC.

Procedures for SEC and PRI airstarts are identical

except for ENG CONT switch position and JFS assist

minimum airspeed requirements.

There are two airstart options available. One option

is a spooldown airstart, for which the throttle is

advanced from OFF to midrange as rpm is

decreasing. There is no specific envelope within

which a spooldown airstart should be initiated, but

once the decision to perform an airstart is made,

airspeed should be adjusted to maintain 250400

knots/0.9 mach. The secondary option is a

JFSassisted airstart which differs from a spool

down airstart in that once the JFS RUN light is on

and PRI mode is confirmed, airspeed can be reduced

to achieve maximum range or maximum endurance

(

200 or 170,

205 or 175 knots respectively, plus

5 knots per 1000 pounds of fuel/store weights and

plus 5 knots if CFT's are installed). The minimum

airspeed for PRI JFSassisted airstarts is 170

knots. The minimum airspeed for all SEC airstarts,

including JFS assisted, is 250 knots.

Figure 37.

. GR1F

16CJ

372

160

180

200

220

240

260

280

300

320

340

360

380

400

420

440

460

480

500

INITIAL AIRSPEED KIAS

INITIAL AL

TITUDE 1000 FT AGL

1F-16X-1-4028X

GW = 23,000-25,000 LB

DI = 0-50

WINDMILLING OR SEIZED ENGINE

30-DEGREE CLIMB MAINTAINED TO 170/250 KIAS

CONFIGURATION:

CONDITIONS:

3G PULLUP TO 30

ZOOM CLIMB TO

ACHIEVE:

250 KIAS

170 KIAS

Low Altitude Zoom Capability

ENGINE F100-PW-229

DATA BASIS ESTIMATED

LG UP

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

400

420

440

INITIAL AL

TITUDE 1000 FT AGL

GR1F16CJ11120X37

MINIMUM RECOMMENDED

EJECTION ALTITUDE

Low Altitude Airstart Capability

DATA BASIS ESTIMATED

GW = 23,000-25,000 LB

DI = 0-50

LG UP

30 DIVE TO DESCENT KIAS OR 3G PULLUP

TO 30 ZOOM CLIMB INITIATED FROM THE

AIRSPEED/ALTITUDE EXISTING AT FIRST

RECOGNITION OF ENGINE FAILURE (60 PER-

AIRSTART INITIATED AT START OF DIVE OR

ZOOM

60 SECONDS ASSUMED AFTER

THROTTLE ADVANCE TO ACHIEVE

USABLE THRUST
DESCENT AIRSPEED IS 250 KIAS

CONFIGURATION:

CONDITIONS:

ENGINE F100-PW-229

INITIAL AIRSPEED KIAS

(JFS RUN LIGHT ON)

CENT RPM)

460

480

500

520

30 DIVE TO 250 KIAS 3G PULLUP TO 30 ZOOM CLIMB

. GR1F

16CJ

373

Figure 38.

T.O. GR1F16CJ1

374

Engine RPM and FTIT Response During

Spooldown and Airstart

ENGINE F100-PW-229

0.2

0.4

0.6

0.8

1.0

1.2

1.4

MACH NUMBER

TITUDE 1000 FEET

400 KIAS/0.9 MACH

JFS ENVELOPE

AIRSTART ENVELOPE

30 DIVE

POINT B TO

SL = 7.9 MIN/40 NM

CONDITIONS:

DRAG INDEX = 0

KIAS = 250

NO WIND

OPTIMUM FLIGHT PATH DURING AN AIRSTART (TYPICAL)

Engine out descent flight path maintains the aircraft in the required airstart envelope.

A 30-degree dive to 400 KIAS/0.9 mach is used to quickly reduce altitude to below

30,000 feet where airspeed can be reduced to 250 KIAS (Point A to B).

GW = 20,000 LB

1F-16X-1-1039A

PRI SPOOLDOWN OR

SEC SPOOLDOWN/JFS

ASSIST-250 KIAS

MIN KIAS WITH JFS

RUN LIGHT ON

AND PRI MODE

CONFIRMED-170

Figure 39.(Sheet 1)

T.O. GR1F16CJ1

375

Engine RPM and FTIT Response During

Spooldown and Airstart

ENGINE F100-PW-229

TIME SECONDS

100

200

400

600

800

1000

RPM %

FTIT C

350 KIAS

10,000 FEET

250 KIAS

35,000 FEET

350 KIAS

35,000 FEET

250 KIAS

10,000 FEET

25%

250/350 KIAS

35,000 FEET

250/350 KIAS

10,000 FEET

RATE OF ENGINE RPM AND FTIT DECAY

AS A FUNCTION OF ALTITUDE AND

AIRSPEED

At low altitude, regardless of airspeed,

the spooldown rate is rapid. Spooldown

rate is slower at higher altitudes as

airspeed is increased.

1F-16X-1-1040X

Figure 39.(Sheet 2)

T.O. GR1F16CJ1

376

NORMAL 25 PERCENT SPOOLDOWN AIRSTART ENGINE RPM AND FTIT

TIME TRACES FOR 250 KIAS/20,000 FEET

Light-off normally occurs within 5 seconds after the throttle is advanced to midrange.

However, engine rpm and FTIT turnaround are slow, making light-off subtle or difficult

to detect. Engine rpm stabilizes momentarily after light-off and FTIT may increase,

stabilize, or decrease as the engine rpm increases.

Engine RPM and FTIT Response During

Spooldown and Airstart

ENGINE F100-PW-229

THROTTLE TO MIDRANGE AT 25%

LIGHTOFF

THROTTLE TO OFF

TIME SECONDS

100

200

400

600

800

1000

1200

FTIT C

RPM %

1F-16X-1-1041X

25%

Figure 39.(Sheet 3)

T.O. GR1F16CJ1

377

THROTTLE TO MIDRANGE AT 50%

LIGHTOFF

THROTTLE TO OFF

100

200

400

600

800

1000

1200

FTIT C

RPM %

50%

NORMAL 50 PERCENT SPOOLDOWN AIRSTART ENGINE RPM AND FTIT

TIME TRACES FOR 250 KIAS/20,000 FEET

Light-off normally occurs within 5 seconds after the throttle is advanced to midrange.

However, engine rpm and FTIT turnaround are slow, making light-off subtle or difficult

to detect. Engine rpm stabilizes momentarily after light-off and FTIT may increase,

stabilize, or decrease as the engine rpm increases.

Engine RPM and FTIT Response During

Spooldown and Airstart

ENGINE F100-PW-229

TIME SECONDS

1F-16X-1-1042X

Figure 39.(Sheet 4)

T.O. GR1F16CJ1

378

NOTE

In most cases, the JFS will engage and

begin to arrest rpm spooldown rate at

approximately 30 percent. Engine rpm

should stabilize on the JFS at a

minimum of 22 percent.

PRI operation is confirmed by SEC

caution light not illuminated.

There are critical requirements which apply to any

airstart attempt. The most important is engine rpm.

High engine rpm provides the best chance of a

successful restart. Therefore, do not delay the

initiation of an airstart in an attempt to reach a

particular flight condition. Initiate an airstart as

soon as it becomes apparent that engine rpm has

decayed below inflight idle (approximately 60

percent rpm). Illumination of the ENGINE warning

light, engine instrument indications, and no

response to throttle movement can help confirm a

flameout. The best conditions for an airstart are at

30,000 feet MSL or below, 250 knots or more, and

high rpm. In general, the success of an airstart is

increased with higher engine rpm, lower altitude,

and higher airspeed.

The throttle should always be advanced to midrange

before 25 percent rpm regardless of FTIT, altitude,

airspeed, JFS assistance, or engine control mode to

prevent rpm decreasing below 12 percent. If rpm

decreases below 12 percent, fuel flow from the main

fuel pump and ignition power from the engine

alternator are lost allowing a further decrease in rpm.

As much as 350 knots or more is required to prevent

rpm from decreasing below 12 percent. If rpm is

allowed to decrease to near zero, 400 knots or more

may be required to regain 12 percent. This requires a

great amount of altitude which may not be available.

If rpm decreases to zero, a seized rotor may occur, due

to temporary engine thermal conditions, after which

it will not rotate even with high airspeeds or by

engaging the JFS. In general, rpm decay rate can be

decreased by increasing airspeed; however, below

30,000 feet MSL, higher airspeeds do not significant

ly affect the rpm decay. Therefore, maintain 250

knots below 30,000 feet MSL for spooldown airstarts.

This airspeed does not maintain rpm above 12

percent; however, it does the best tradeoff between

the rate of rpm spooldown and loss of altitude.

Stabilizing or increasing rpm is normally the first

indication of an engine lightoff. Lightoff normally

occurs within 5 seconds after advancing the throttle.

However, rpm turnaround is slow, making lightoff

subtle and difficult to detect. FTIT response is slow

and may reverse trend one or more times during the

start sequence. Neither condition should be confused

with a hung start.

DEEC overtemperature protection logic attempts to

limit FTIT to 870

C, which may result in decreasing,

hung, or slowly increasing engine rpm. If a hung start

occurs (stabilized FTIT 870

C or less, rpm stabilized

below 60 percent), increase airspeed to a maximum of

400 knots/0.9 mach if altitude allows. If hung start

continues or there is no throttle response, reinitiate

the airstart with the ENG CONT switch in SEC when

below 30,000 feet MSL.

During an SEC start, 4560 seconds is required for

engine lightoff and acceleration to midrange from

the time the throttle is advanced from OFF.

If a SEC airstart is initiated at high RPM (above 40

percent), as much as 30 seconds following throttle

advancement may be required for RPM to stabilize or

begin to increase, indicating a successful light. This

slow engine response should not be confused with a

nolight response in which case RPM would continue

to decrease.

SEC airstarts initiated at lower RPM show positive

RPM turnaround within 15 seconds of placing

throttle to midrange. RPM continuing to decrease

after 15 seconds from throttle advancement or

stabilizing at a minimum of 22 percent with the JFS

RUN light on, indicates a nolight has occurred.

High Altitude Airstart Considerations

PW 229

Refer to figure 39. At 30,000 feet MSL and above, the

airstart (PRI or SEC) should be initiated by retarding

the throttle to OFF then advancing to midrange as

soon as possible regardless of FTIT or airspeed.

Always advance the throttle to midrange by 25

percent engine rpm. Dive to obtain 400 knots/0.9

mach to minimize rpm spooldown rate and quickly

decrease altitude to less than 30,000 feet MSL. If

lightoff indications are not noted within 20 seconds

in PRI or 30 seconds in SEC after advancing the

throttle, or if FTIT exceeds 870

C, retard the throttle

to OFF and reinitiate the airstart with the ENG

CONT switch in

PRI,

NORM, regardless of

which control mode the engine is presently in. If a

hung start occurs (rpm stable with FTIT stable at

870

C or less), keep the throttle at midrange until

below 30,000 MSL then reinitiate the airstart with

the ENG CONT switch in SEC.

T.O. GR1F16CJ1

379

At high altitudes, the dive should be at approximately

30 degrees to gain or maintain 250 knots below 30,000

feet. Once established, approximately 510 degrees of

dive should maintain airspeed. Note that airspeed

should not be reduced to less than 250 knots until the

JFS RUN light is on, and PRI mode is confirmed.

Unless an airstart is obviously impossible (total lack

of fuel, engine seizure, etc.), do not become tempted to

establish a maximum range or maximum endurance

glide. The first consideration should be an immediate

spooldown airstart attempt even if the engine failed

for no apparent reason. If airstart airspeed is not

maintained, rpm decreases at a faster rate. The only

airstart option available is then a JFSassisted

airstart. Time constraints due to EPU fuel consump

tion must be considered. A maximum range or

maximum endurance glide from above approximately

35,000 feet may exhaust EPU fuel prior to landing.

(Refer to T.O. GR1F16CJ11, figure A63.)

The reason for most airstart failures above 30,000

feet MSL is the engine inability to light off and not

due to the DEEC's inability to control the start.

Therefore, all second airstart attempts above 30,000

feet MSL should be made with the ENG CONT switch

PRI,

NORM. The engine does not have a

lightoff problem below 30,000 feet; therefore, all

second airstart attempts below 30,000 feet MSL

should be made with the ENG CONT switch in SEC.

When below 20,000 feet MSL, select JFS START 2.

Activating the JFS above 20,000 feet is prohibited

since successful JFS start/motoring of engine is

unlikely and the brake/JFS accumulators will be

depleted. If the JFS RUN light is on and PRI mode is

confirmed, airspeed may be reduced to achieve

maximum range or maximum endurance. If the JFS

RUN light is on and SEC mode is confirmed,

maintain 250 knots minimum. With the JFS

running, EPU fuel consumption is also reduced.

Low Altitude Airstart Considerations

PW 229

Due to the limited time available and the rapid rpm

spooldown rate at low altitude, some additional

considerations are required. Below approximately

10,000 feet MSL, rpm decreases rapidly regardless

of airspeed and remains between 5025 percent for

only 510 seconds; therefore, rpm should be closely

monitored. Advance the throttle to initiate the

airstart before rpm goes below 25 percent

regardless of FTIT indication. This action should

insure that lightoff occurs prior to 12 percent rpm.

Start the JFS immediately after advancing the

throttle (if airspeed is below 400 knots).

Following a zoom climb, plan to arrive at 250 knots.

Airspeed may be reduced to achieve maximum

range or maximum endurance (200 or 170 knots,

respectively) only if PRI mode is confirmed and the

JFS RUN light is on. If SEC mode is confirmed or

tower shaft failure is suspected, maintain 250 knots

minimum. If a higher airspeed is maintained or an

attempt is made to gain airspeed to delay the rpm

decay, available time may be reduced to the point

that an airstart is not possible. During any low

altitude airstart attempt, constantly evaluate

altitude above the ground relative to airstart

success. Do not delay ejection below 2000 feet AGL

unless the engine is producing thrust capable of

maintaining level flight or safely controlling the

sink rate or unless a flameout landing can be

accomplished.

Airstart Procedures

PW 229

To perform an airstart, retard throttle to OFF,

then

advance throttle to midrange.

NOTE

If the throttle is retarded to OFF to clear

a stall, it should be maintained in OFF for

a few seconds to allow the stall to clear.

Start the JFS below 20,000 feet MSL and below 400

knots immediately after the throttle is advanced to

midrange to initiate the spooldown airstart.

If the JFS stops running or fails to run within 30

seconds, do not reattempt a JFS start until the

brake/JFS accumulators have time to recharge. Allow

1 minute of engine rotation (either windmilling or

JFS assisted) at 12 percent rpm or above to insure

that the brake/JFS accumulators are fully recharged.

Recharging begins 34 seconds before the JFS RUN

light illuminates or 30 seconds after selecting a start

position (in the event of a JFS failure to run).

Recharging begins regardless of JFS switch position.

In the event of a JFS shutdown, the JFS switch does

not relatch in either start position while the JFS is

spooling down. Spooldown from full governed speed

takes approximately 17 seconds. The JFS switch

must be cycled to OFF and then to START 2 to

reinitiate a JFS start. It is possible to complete the

spooldown before the brake/JFS accumulators are

recharged if the JFS ran for only a short time.

When the airstart is completed, turn the JFS off (if

tower shaft failure is not suspected). Reset the main

generator using the ELEC CAUTION RESET button

and verify MAIN GEN and STBY GEN lights are off.

Cycle the EPU switch to OFF, then back to NORM.

T.O. GR1F16CJ1

380Change 1

With engine failure or flameout,

OBOGS is inoperative. Activate EOS if

OXY LOW warning light illuminates

above 10,000 feet cockpit altitude.

To accomplish an airstart:

Throttle-OFF, then midrange.

NOTE

FTIT will decrease rapidly when

throttle is OFF.

Airspeed-As required.

Above 30,000 feet MSL, dive at 400

knots/0.9 mach. Below 30,000 feet MSL,

establish approximately 250 knots. When

below 20,000 feet MSL with the JFS RUN

light on and PRI mode confirmed, airspeed

can be reduced to achieve maximum range

or maximum endurance (

200 or 170,

205 or 175 knots, respectively, plus 5 knots

per 1000 pounds of fuel/store weights and

plus 5 knots if CFT's are installed).

NOTE

If maximum gliding range is not a factor,

consider maintaining 250 knots above

10,000 feet AGL to reduce rpm spooldown

rate (in case of JFS failure). Below 10,000

feet AGL with the JFS RUN light on and

PRI mode confirmed, maintain maximum

range or maximum endurance airspeed.

JFS switch-START 2 below 20,000 feet MSL

and below 400 knots.

NOTE

If the JFS switch is erroneously placed

to START 1, leave it there.

If the JFS RUN light does not illuminate

or goes off once illuminated, place the

JFS switch to OFF and reattempt

START 2 when the brake/JFS accumu

lators are recharged. The JFS switch

does not relatch in either start position

while the JFS is spooling down.

Stores-Jettison (if required).

If stores jettison is attempted after main

generator drops off line but before EPU

generator powers the SMS (approximately 5

seconds delay), stores will not jettison.

NOTE

Visually confirm the stores have

jettisoned and jettison again if re

quired.

If a no light, hot start, or stall occurs:

Throttle-OFF.

ENG CONT switch-SEC if below 30,000 feet

MSL (250 knots minimum).

NOTE

Place the ENG CONT switch to SEC

prior to placing the throttle to

midrange, otherwise a start anomaly

may result.

The proximity of the ENG CONT

switch to the JFS switch makes the

JFS switch susceptible to being

bumped to OFF when selecting SEC.

Throttle-Midrange.

If a hung start occurs:

Airspeed-Increase (maximum of 400 knots/

0.9 mach).

If hung start continues or there is no throttle

response:

Throttle-OFF when below 30,000 feet MSL.

10. ENG CONT switch-SEC (250 knots mini

mum).

NOTE

Place the ENG CONT switch to SEC

prior to placing the throttle to

midrange, otherwise a start anomaly

may result.

The proximity of the ENG CONT

switch to the JFS switch makes the

JFS switch susceptible to being

bumped to OFF when selecting SEC.

11. Throttle-Midrange.

If engine does not respond normally after airstart is

completed:

12. Refer to FLAMEOUT LANDING, this section.

T.O. GR1F16CJ1

Change 1381

If engine responds normally:

Do not turn JFS or EPU off if indicated

rpm is below 60 percent with adequate

thrust (e.g., tower shaft failure).

12. JFS switch-OFF.

13. ELEC CAUTION RESET button-Depress.

Verify MAIN GEN and STBY GEN lights are

off.

14. EPU switch-OFF, then NORM.

15. ADI-Check for presence of OFF and/or AUX

warning flags.

If warning flag(s) is in view, refer to EGI

FAILURE, this section.

16. Throttle-As required.

NOTE

If the SEC caution light is on, refer to

SEC CAUTION LIGHT, this section.

17. Land as soon as possible.

18. Refer to ACTIVATED EPU/HYDRAZINE

LEAK, this section.

ENGINE MALFUNCTIONS

129

The EMS compares expected versus actual engine

operation. The purpose of the EMS MFL is to provide

maintenance personnel with an early indication of

an engine condition which requires correction. No

action is required for an engine MFL at anytime

during a flight.

Low altitude, for engine malfunction purposes, is

generally defined as 10,000 feet AGL or below. If an

engine malfunction is suspected, the initial reaction

should be to trade excess airspeed for altitude.

Unless

a suitable airfield is within gliding distance, turns

should be avoided as they decrease the amount of

time/altitude available to successfully recover engine

performance or prepare for ejection. Optimizing the

exchange of airspeed for altitude must be a priority

action for any engine malfunction. Above 310 knots,

more time is available by performing a zoom climb

using a 3g pullup to 30degree climb until

approaching the desired airspeed (use approximately

50 knots lead point) and then initiating a zerog

pushover. Below 310 knots and above the minimum

recommended ejection altitude, more time is

available by performing a constant altitude decelera

tion to the desired airspeed. If below the minimum

recommended ejection altitude and below 310 knots,

primary concern should be to trade excess airspeed

for altitude in preparation for ejection. If appropriate,

jettison stores as soon as possible.

For any situation where automatic activation of the

EPU is relied upon, verify that the EPU run light is

on to insure that the EPU has started. If the EPU run

light is off, position the EPU switch to ON.

SEC is a highly reliable backup engine operating

mode. However, in certain circumstances the engine

may malfunction in SEC following an auto transfer,

or continue to malfunction in SEC following a manual

transfer. Returning to PRI may result in proper

engine response, due to either the resetting of

internal hydromechanical control pressures or to the

resetting of digital engine control logic.

Idle thrust in SEC during ground operation is

approximately twice that in PRI. After landing in

SEC, consider minimizing taxi distance and consider

following HOT BRAKES procedures, this section.

Engine Fire

129

Generally, the first indication of fire in the engine

compartment is the ENG FIRE warning light.

Abnormal fuel indications (quantity/flow) may also

be present. FTIT probably will not be higher than

normal. Explosions, vibrations, or engine instrument

fluctuations are usually indicative of a serious engine

problem; engine failure may be imminent. Immediate

action should be taken to reduce thrust to the

minimum practical level after attaining safe ejection

parameters. If within gliding distance of a suitable

runway, consider shutting the engine down. Suffi

cient time should exist to analyze the situation and

make an ejection versus land decision. The ejection

decision should be based on visual and/or cockpit

indications that the fire is persisting. Cockpit

indications include continued illumination of the

ENG FIRE warning light and subsequent FLCS

malfunctions/degraded flight controls or subsequent

loss of either hydraulic system.

Fires can also occur in the nozzle area when using AB.

These fires are the result of portions of the nozzle

failing which allows the AB plume to burn through

the nozzle. Ventilation should inhibit forward

movement of the fire into and through the engine bay.

Since these fires are aft of the detection circuit, the

ENG FIRE warning light will not illuminate.

Additionally, the nozzle position indications are

normal, and there are no vibrations or instrument

fluctuations. In most cases, these ABrelated nozzle

T.O. GR1F16CJ1

382Change 1

fires are detected by someone outside the aircraft

(wingman, tower, etc.). When operating in AB and a

fire is reported at the rear of the aircraft, retard

throttle below AB immediately. This action should

extinguish a nozzle fire within approximately 3045

seconds and minimize damage to the aircraft skin,

speedbrakes, nozzle, and flight controls; however,

nozzle damage may result in a noticeable thrust loss.

If on takeoff and the conditions permit:

Abort.

If takeoff is continued:

Climb.

Maintain takeoff thrust until minimum

recommended ejection altitude is attained

and then throttle to minimum practical.

Stores-Jettison (if required).

At a safe altitude:

Throttle-Minimum practical.

If fire occurred in AB, ENG FIRE warning

light may not illuminate. Fire should

extinguish after throttle is retarded; how

ever, nozzle damage may result in lower than

normal thrust.

If ENG FIRE warning light goes off:

FIRE & OHEAT DETECT button-Depress.

Determine if fire detection circuit is

functional.

If fire persists:

Eject.

If fire indications cease:

Land as soon as possible.

OVERHEAT Caution Light

129

Detection of an overheat condition in the engine

compartment, ECS bay, MLG wheel wells, or EPU

bay illuminates the OVERHEAT caution light.

Accomplish as many of the following as required to

extinguish the light. If the light goes off, verify the

integrity of the detection circuit by depressing the

FIRE & OHEAT DETECT button and land as soon as

possible.

If OVERHEAT caution light illuminates:

Throttle-Minimum practical.

FIRE & OHEAT DETECT button-Depress.

Determine if fire detection circuit is

functional.

If OVERHEAT caution light remains on (or detect

circuit checks bad) and EPU is running:
3.

EPU switch-OFF (if feasible).

If the EPU was manually turned on, consider

turning it off to determine if it is the source

of the overheat condition. If the OVERHEAT

caution light remains on, the EPU should be

turned back on.

If OVERHEAT caution light remains on (or detect

circuit checks bad):
4.

OXYGEN-100%.

AIR SOURCE knob-OFF.

External fuel cannot be transferred in OFF

or RAM. Consider jettisoning tanks to

decrease drag if range is critical and the ECS

cannot be turned on for short periods of time

to transfer fuel.

With the ECS shut down or the AIR

SOURCE knob in OFF or RAM, the

gsuit does not inflate and PBG is

disabled.

Descend to below 25,000 feet and reduce

airspeed to below 500 knots.

When airspeed is reduced and cockpit is depressu

rized:
7.

AIR SOURCE knob-RAM (below 25,000

feet).

External fuel cannot be transferred in OFF or

RAM. Consider jettisoning tanks to decrease

drag if range is critical and the ECS cannot be

turned on for short periods of time to transfer

fuel.

With the ECS shut down or the AIR

SOURCE knob in OFF or RAM, the gsuit

does not inflate and PBG is disabled.

Nonessential electrical equipment-Off.

NOTE

If in VMC and the ADI and HSI are not

required for flight, the INS should be

considered nonessential.

T.O. GR1F16CJ1

383

If OVERHEAT caution light still remains on (or

detect circuit checks bad):

TANK INERTING switch-TANK INERT

ING even if Halon is not available.

10. LG handle-DN (300 knots/0.65 mach maxi

mum). (Use DN LOCK REL button if required.)

If LG handle does not lower, select

BRAKES CHAN 2 and position ALT

FLAPS switch to EXTEND.

11. Land as soon as possible.

Oil System Malfunction

129

An oil system malfunction may be indicated by the

EMS, the OIL pressure indicator, the NOZ POS

indicator, and the HYD/OIL PRESS warning light.

An oil system malfunction is characterized by a

pressure (including fluctuations) below 15 psi at

IDLE or 25 psi at MIL, pressure above 65 psi at any

throttle setting, pressure fluctuations greater than

5 psi, or continuous presence of the ENG LUBE

LOW PFL.

Engine oil level decreasing below approximately 40

percent of normal capacity for 15 seconds results in

activation of an ENG LUBE LOW PFL. Further oil

level decrease may cause the exhaust nozzle to fail to

an aerodynamically balanced position and there

may be a decrease in thrust and a larger than normal

NOZ POS indication. The HYD/OIL PRESS warning

light may not illuminate until most of the usable oil

is lost.

NOTE

An ENG LUBE LOW PFL can occur as

the result of sustained longitudinal

acceleration during takeoff or during

other maneuvering.

High airspeeds (especially at low altitude), high

throttle settings, and/or throttle movements are

undesirable when oil pressure is abnormally low.

Initial reaction to an oil system malfunction at low

altitude should be to gain altitude and, if oil pressure

is low, reduce airspeed. If oil pressure is 10 psi or

above, consider using MIL or AB thrust to quickly

attain desired cruise altitude. If oil pressure is below

10 psi, increase altitude and reduce airspeed by

performing a fixed throttle climb. If the altitude

gained is insufficient for a safe cruise, a slow throttle

advance followed by a slow throttle reduction, when

at a sufficient cruise altitude, may be performed. Do

not make subsequent throttle movements unless

required to sustain flight.

Anticipate engine seizure approximately 5 minutes

after oil pressure drops below 10 psi. Use minimal

throttle movement and reduced thrust settings to

maximize time. Minimize maneuvering g to minimize

loads. Plan an approach which allows a flameout

landing from any position should engine seize. Refer

to SIMULATED FLAMEOUT (SFO) LANDING and

FLAMEOUT LANDING, this section.

The EPU should be manually activated if engine

seizure is anticipated (i.e., oil pressure decreases

below 10 psi); otherwise, if the EPU does not start

automatically when the engine seizes, the short time

remaining before loss of control may be inadequate

for recognition of the EPU failure and corrective

action. Monitor hydrazine use after activating the

EPU. If consumption rate is too high, cycle EPU

switch to OFF, then NORM to conserve hydrazine. Be

prepared to place the EPU switch back to ON if the

engine seizes.

If an oil system malfunction is suspected:

Range-Maximize.

If oil pressure is 10 psi or above and the

nearest suitable airfield is not within

gliding distance, consider using MIL or AB

thrust to quickly gain altitude and/or

decrease distance to the nearest suitable

airfield. If oil pressure is below 10 psi, attain

desired cruise conditions using minimum

throttle movement and then slowly retard

to the minimum setting required.

When oil pressure is below 10 psi,

throttle movement, high throttle set

tings, or high airspeeds may accelerate

or cause engine seizure.

Do not start the JFS if engine seizure

has occurred or is anticipated. Start

ing the JFS may result in no brake/JFS

accumulator pressure for the brakes.

Plan to land at the nearest suitable airfield.

If oil pressure is low (with or without an ENG LUBE

LOW PFL):

Stores-Jettison (if required).

T.O. GR1F16CJ1

384Change 1

EPU switch-ON, if oil pressure decreases

below 10 psi.

Monitor hydrazine use. If consumption rate

is too high, cycle EPU switch to OFF, then

NORM to conserve hydrazine. Be prepared

to place EPU switch back to ON if the engine

seizes.

Land as soon as possible.

Plan to fly an SFO. Refer to SIMULATED

FLAMEOUT (SFO) LANDING and

FLAMEOUT LANDING, this section.

Refer to ACTIVATED EPU/HYDRAZINE

LEAK, this section.

If oil pressure is fluctuating or high (without an ENG

LUBE LOW PFL):

Land as soon as practical at the nearest

suitable airfield.

If oil pressure is normal and ENG LUBE LOW PFL

occurred:

FACK,

FAULT ACK button -

Depress to acknowledge fault.

Turn toward the nearest suitable airfield.

Maintain straight, level, and unaccelerated

flight for 15 seconds.

FACK,

FAULT ACK button -

Depress for fault recall.

Presence of an ENG LUBE LOW PFL after 15

seconds of straight, level, and unaccelerated

flight is a valid indication of low oil quantity.

If ENG LUBE LOW PFL was not present during fault

recall:

Land as soon as practical at the nearest

suitable airfield.

If ENG LUBE LOW PFL was present during fault

recall or recurs after fault recall:

Stores-Jettison (if required).

EPU switch-ON, if oil pressure decreases

below 10 psi.

Monitor hydrazine use. If consumption rate

is too high, cycle EPU switch to OFF, then

NORM to conserve hydrazine. Be prepared

to place EPU switch back to ON if the engine

seizes.

10. Land as soon as possible.

Plan to fly an SFO. Refer to SIMULATED

FLAMEOUT (SFO) LANDING and FLAME

OUT LANDING, this section.

11. Refer to ACTIVATED EPU/HYDRAZINE

LEAK, this section.

ENGINE FAULT Caution Light

129

Illumination of the ENGINE FAULT caution light

indicates that an engine PFL item was detected.

If ENGINE FAULT caution light illuminates:

PFLD-Note PFL(s) displayed.

FACK,

FAULT ACK button-De

press to acknowledge fault.

Refer to PILOT FAULT LIST - ENGINE, this

section.

FACK,

FAULT ACK button-De

press to perform fault recall.

The failure condition no longer exists if the

PFL is not present during the fault recall.

SEC Caution Light

129

Illumination of the SEC caution light indicates that

the engine is operating in SEC. If the ENG CONT

switch is in

PRI,

NORM and the SEC

caution light illuminates, an automatic transfer to

SEC has likely occurred. Normal SEC operation is

characterized by the SEC caution light, a fixed closed

exhaust nozzle, and AB unavailable. The ENG

CONT switch does not have to be positioned to SEC.

NOTE

If the rpm indication is also zero, the

engine alternator has failed.

There are no throttle restrictions while operating

subsonic in SEC. If supersonic when transfer to SEC

occurs, the throttle must remain at MIL or above

until subsonic.

The thrust level at MIL, while operating in SEC, is

7095 percent of that provided (for the same throttle

position and flight condition) in PRI. During landing

in SEC, idle thrust is approximately twice that in PRI

with a normal nozzle because the nozzle is closed.

Content .. 21 22 23 24 ..

F16C/D. FLIGHT MANUAL (2002) - page 23

F16C/D. FLIGHT MANUAL (2002) - page 23