F16C/D (BLOCKS 50 AND 52+). FLIGHT MANUAL (15 OCTOBER 2002) - page 57

T.O. GR1F16CJ1

68

STORE SEPARATION

Symmetrical store releases and wingtip AIM9

missile launches can be accomplished with no

unusual aircraft responses. Separation of the

300gallon fuel tank produces negative g on the

aircraft. The magnitude of this response depends on

the amount of fuel remaining in the tank and the

mach number at release. Separating a full centerline

fuel tank at supersonic speeds produces the worst

response (up to -1.5g).

Separation of 370gallon fuel tanks produces a

minimal aircraft response. Separation of a single

370gallon fuel tank will initially produce aircraft

positive g response and roll away from the separated

tank (up to +1g and 15 degrees of bank).

OUTOFCONTROL CHARACTERISTICS

A departure is a loss of aircraft control that is

characterized primarily by uncommanded aircraft

motions or failure of the aircraft to respond to control

commands. In a pitch departure, the AOA increases

beyond the normal controllable range. In a yaw

departure, the sideslip angle increases beyond the

normal controllable range first, although a pitch

departure may immediately follow. The automatic

features of the FLCS normally prevent departures.

However, departures may occur when Section V

limits are exceeded or in certain circumstances when

the FLCS provides only marginal protection.

With a lateral asymmetry in excess of 300 pounds

(including wing tip missile and internal/external

fuel), abrupt maneuvering on or near the CAT I AOA

limiter can result in a departure if the aircraft is

configured with any of the following:

D

300gallon fuel tank.

D

370gallon fuel tanks.

D

Inlet mounted pod(s).

D

Combination of a centerline store plus stores (or

suspension equipment) at stations 3 and/or 7.

With these loadings, maneuvering at high altitude

(above 25,000 feet) increases the probability of a yaw

departure. Even moderate control commands may

cause aircraft with some CAT I loadings to depart

above 25,000 feet.

Abrupt maneuvering on or near the CAT I AOA

limiter at slow airspeeds (less than 200 knots) may

result in a departure.

YAW DEPARTURE

A yaw departure occurs when sideslip increases

beyond the normal controllable range (i.e., beyond

about 15 degrees). The primary indication of most

yaw departures is an abrupt nose slice. The aircraft

then fails to respond properly to pilot commands

and exhibits uncommanded motions. AOA is in the

normal range (-5 to +25 degrees) during the initial

phase of the nose slice. Immediately following a yaw

departure, a pitch departure usually occurs

resulting in AOA indication of -5 or +32.

It is possible for the sideslip to briefly exceed the

normal controllable range without the aircraft

experiencing uncommanded motions. In this situa

tion, the pilot's only indication of a departure may be

noticeable sideforces. These brief departures typical

ly selfrecover within 5 seconds.

A yaw departure may occur while maneuvering on or

near the CAT I AOA limiter in the 0.80 to 0.95 mach

range, especially at high altitude (above 25,000 feet).

Maneuvering at high altitude is more critical than

low altitude because mach effects reduce directional

stability. These yaw departures usually result from

maximum command left rolls; but they may also

occur during symmetric maneuvering.

The possibility of a yaw departure is increased

whenever the aircraft is configured with stores or

suspension equipment, especially a centerline store.

In general, the possibility of departure increases as

the number, weight, and size of such equipment or

stores increases. Susceptibility to a yaw departure

increases significantly with lateral asymmetry, with

leftwingheavy loadings being more likely to depart

than rightwingheavy loadings. In addition, a

heavier GW aircraft is generally more likely to

experience yaw departures. CAT I loadings most

susceptible to yaw departures have one or more of the

following characteristics:

D

Centerline store.

D

Inlet mounted pod(s).

D

Lateral asymmetry greater than 300 pounds at

stations 1, 2, or 3.

Yaw departures can be minimized by avoiding abrupt

maneuvers in the 0.80 to 0.95 mach range with a

centerline store, especially above 25,000 feet. Either

unload the aircraft prior to making roll commands or

command only minimum required roll rate when

operating near the CAT I AOA limiter. With

centerline store loadings having lateral asymmetries

greater than 300 pounds and inlet mounted pod(s),

avoid abrupt aft stick commands above 25,000 feet.

T.O. GR1F16CJ1

69

The probability of a yaw departure

significantly increases above 25,000

feet for CAT I loadings having a

centerline store, a lateral asymmetry

greater than 300 pounds, and inlet

mounted pod(s). With these loadings,

moderate, fullaftstick inputs at

35,000 feet and 300 knots have caused

yaw departures and spins.

A yaw departure may also occur with large

airtosurface lateral asymmetries with the STORES

CONFIG switch in the CAT III position. These

departures can be avoided if abrupt control

commands are not used with lateral asymmetries in

excess of 1500 pounds at station 3 (or equivalent).

A yaw departure results in one of the following:

D

A selfrecovery. The selfrecovery may occur quickly

(within approximately 5 seconds). If a pitch

departure follows the yaw departure, the selfrecov

ery may require 1020 seconds. Random and

possibly abrupt pitch, roll, and yaw rates may occur.

D

A deep stall.

D

An upright spin.

PITCH DEPARTURE

A pitch departure occurs when the AOA exceeds the

AOA/g limiter. A pitch departure is classified either

as upright if the AOA is positive or as inverted if the

AOA is negative. Although the AOA indicator

displays a maximum of 32 degrees and a minimum of

-5 degrees, the actual AOA during a departure will

exceed these values. In highly oscillatory departures,

the AOA indicator may momentarily indicate an AOA

below 32 degrees. Airspeed indications are erroneous

and generally oscillate between the minimum value

and approximately 150 knots.

An upright pitch departure occurs when the AOA

exceeds the positive AOA/g limiter. Above 25 degrees

AOA, both horizontal tails are commanded to full

trailing edge down by the pitch axis of the FLCS to try

to reduce the AOA. If AOA exceeds 35 degrees, the

yaw rate limiter provides antispin commands to the

rudder, flaperons, and horizontal tails. Pilot roll and

rudder commands are inhibited and pitch stick

commands are ineffective without use of the MPO

switch.

An inverted pitch departure occurs at negative AOAs

when the AOA significantly exceeds the negative g

limiter. During the departure, the pitch axis of the

FLCS commands the horizontal tails to full trailing

edge up to try to return AOA to the normal range.

Pitch stick commands are ineffective without use of

the MPO switch.
If AOA is below -5 degrees and airspeed is less than

170 knots, the yaw rate limiter provides antispin

commands to the rudder. During an inverted

departure, roll and rudder commands should be

avoided. Pilot roll and rudder commands are

inhibited when the MPO switch is engaged.
An upright or inverted pitch departure can occur

when the aircraft is flown to airspeeds below that

indicated by the low speed warning tone. Inverted

pitch departures usually result from inverted flight

at high pitch attitudes and low airspeeds, such as

those often encountered by going over the top at too

slow an airspeed. An upright or inverted pitch

departure may also occur at any pitch attitude if

abrupt stick commands are made at airspeeds below

200 knots. Simultaneous abrupt roll and aft stick

commands are especially likely to cause an upright

pitch departure. However, the aircraft can be safely

flown to the AOA/g and roll limiters below 200 knots

with smooth commands.
An upright pitch departure may also result from a

yaw departure. In addition, recovery from an

inverted pitch departure may cause the aircraft to

pendulum into an upright departure and vice versa.
The likelihood of a pitch departure increases if the

aircraft is configured with stores (especially 370gal

lon fuel tanks), if the speedbrakes are opened, or if the

CG is near the aft limit.
Pitch departure characteristics are strongly in

fluenced by the airspeed and aircraft rates present at

departure. A low airspeed departure (below 200

knots) may have relatively benign uncommanded

pitch, roll, and yaw motions. Higher airspeed

departures are usually very dramatic with large

uncommanded pitch, roll, and yaw motions which

may persist for 10 seconds or more.
It is possible for the AOA to briefly exceed the AOA/g

limiter without the aircraft experiencing

uncommanded motions. In this situation, the pilot's

only indication of a departure may be a failure of the

aircraft to respond to control commands. These brief

departures typically selfrecover within 5 seconds.
A pitch departure results in one of the following:

D

A selfrecovery which occurs within 520 seconds.

Random and possibly abrupt pitch, roll, and yaw

rates may occur.

D

A deep stall.

D

A spin.

T.O. GR1F16CJ1

610

DEEP STALL

If the aircraft does not selfrecover following a

departure, a deep stall may have developed. A deep

stall is an outofcontrol flight condition in which the

aircraft stabilizes at an AOA of approximately 60

degrees (upright) or -60 degrees (inverted) with low

yaw rates. The FLCS attempts to return AOA to the

normal range by commanding full horizontal tail

deflection. However, the full horizontal tail deflection

is insufficient to return AOA to the controllable

range. The aircraft has entered a deep stall if the AOA

remains outside the controllable range. In a deep stall

the AOA indicator will be pegged at 32 or -5 degrees.

Recovery to controlled flight requires that the pilot

pitch rock the aircraft with the MPO switch in OVRD.

The MPO switch allows the pilot to override the FLCS

and to manually control the horizontal tails.

Airspeed indications are erroneous in a deep stall and

fluctuate between 0150 knots. Altimeter indications

should be considered reliable; however, aircraft

oscillations may cause momentary stabilized or even

slightly increased altitude indications. Sink rate in a

deep stall is usually between 10,000 and 15,000 feet

per minute. The normal load factor is approximately

1g or -1g for upright and inverted deep stalls,

respectively.

Upright deep stalls may be very stable with little or

no pitch, roll, and yaw motions or may be very

oscillatory with large pitch, roll, and yaw motions.

Generally, a clean configuration results in a deep stall

with a near wingslevel pitching motion. If stores are

being carried, especially a 300gallon fuel tank or

370gallon fuel tanks, the deep stall may be very

oscillatory, masking the pitch motions.

In an upright deep stall, the nose of the aircraft

usually oscillates 

"

15 degrees about a slightly

noselow pitch attitude. Pitch oscillations may be as

high as 

"

40 degrees and normally reverse direction

approximately every 3 seconds. Roll reversals up to

"

90 degrees from wings level may occur and the yaw

rate tends to cyclically reverse back and forth and

may be as high as 40 degrees per second. A slow net

heading change, usually to the left, may occur.

Inverted deep stalls may be either stable or highly

oscillatory in pitch, depending upon the CG. If there

is little or no pitch motion, the nose is slightly above

the horizon and the wings are generally level. If the

deep stall is oscillatory in pitch, the nose may oscillate

above and below the horizon by as much as 

"

20

degrees. Yaw and roll oscillations in an inverted deep

stall are normally smaller than those during an

upright deep stall.

The aircraft is most likely to stabilize in a deep stall

if it does not selfrecover within two postdeparture

pitch oscillations. The likelihood of a deep stall

occurring after a departure is also dependent upon

the aircraft CG and configuration. An inverted deep

stall can occur at a more forward CG than an upright

one. The likelihood of a deep stall developing after a

departure increases as the CG moves farther aft and

if stores (especially 370gallon fuel tanks) are loaded.

SPIN

A spin is a deep stall with a significant sustained yaw

rate in one direction (greater than 30 degrees per

second). The pitch, roll, and yaw oscillations

associated with a deep stall should not be confused

with the continuous yaw rotation associated with a

spin. AOA, airspeed indications, and altitude loss are

similar to those during deep stalls. Spins can be either

upright or inverted, although inverted spins are

much less likely to occur than upright spins.
The yaw rate limiter is effective in preventing an

upright spin with most CAT I loadings. However,

following a yaw departure above 25,000 feet, aircraft

with CAT I loadings that have all the following

characteristics may spin:

D

Centerline store.

D

Inlet mounted pod(s).

D

Lateral asymmetry greater than 300 pounds at

stations 1, 2, or 3.

Upright spins following a yaw departure can be

disorienting. The initial portion of the spin is

characterized by highly oscillatory pitch and roll

motions and a high yaw rate (70 to 100 degrees per

second). Initially, the aircraft spins roughly around

the aircraft's flight path at departure. As the spin

continues, the rotation axis eventually becomes

vertical. Very noticeable forward g (eyeballs out) and

sideforces are present.

Yaw rate usually decreases to near zero within 10 to

25 seconds. The g forces decrease noticeably as yaw

rate decreases, which may give the sensation that

yaw rate is lower than it actually is. Use outside

references to determine when the yaw rate has

stopped. A recovery may occur after yaw rate has

decreased to near zero. If recovery does not occur, the

aircraft has settled into a deep stall and pitch rocking

must be used to recover the aircraft to controlled

flight. However, because pitch rocking is less effective

when a yaw rate is present, pitch rocking should not

begin until yaw rotation stops or is minimized (if

altitude permits).

T.O. GR1F16CJ1

611

A spin may also occur following any departure with a

CAT III loading that has a large lateral asymmetry

from airtosurface stores. These spins may be fast,

flat, and possibly unrecoverable.

An inverted spin can be caused by pilot rudder and

roll commands if they are not released following an

inverted departure.
The yaw rate limiter is effective in preventing an

inverted spin with all CAT I loadings. However, large

lateral asymmetries from airtosurface stores on

CAT III loadings may overpower the yaw rate limiter

and cause unrecoverable inverted spins.

RECOVERIES

SelfRecovery

Recovery from most departures is automatic,

requiring only release of the controls. Once the

controls are released, selfrecoveries usually occur

within the first two postdeparture pitch oscillations

(1020 seconds). Recovery is characterized by the nose

pitching down to a steep dive angle, increasing

airspeed, and AOA and sideslip returning to the

normal range. Some postdeparture yaw and roll

oscillations may be evident, particularly if the

departure was in yaw. To prevent departure reentry,

the airspeed should be allowed to increase to 200

knots prior to dive recovery. Flight control failure

indications may be present after recovery from any

departure.

Deep Stall Recovery

The aircraft should be allowed the opportunity to

selfrecover if altitude permits. Initiating pitch

rocking too soon should be avoided because it can

aggravate postdeparture roll and yaw motions, which

can significantly lengthen recovery time.
If recovery is not apparent after two postdeparture

pitch oscillations (1020 seconds) or if altitude is a

factor, the aircraft must be rocked out of a deep stall.

To pitch rock the aircraft, the MPO switch must be

firmly held in OVRD until recovery is complete.

Recognize any pitching motions and begin stick

cycling inphase with these motions. If no pitch

motions are apparent, an abrupt maximum command

stick input to pitch the nose away from the ground

(full aft stick for an upright deep stall, full forward for

an inverted deep stall) will reverse the horizontal tail

deflection and should generate a noticeable pitch

rate. The best indicator for timing stick cycles is the

nose position relative to the horizon, or if no outside

references are available, the ADI may be useful. In an

upright deep stall, an aft stick command increases

the AOA and pitch angle. When the nose reaches its

highest point and reverses direction, a full forward

stick command reinforces the nosedown pitch rate.

One complete pitch rocking cycle takes approximate

ly 6 seconds, during which time the aircraft descends

1000 to 1500 feet.
If the nosedown pitch rate is large enough, the

upright deep stall is broken and AOA returns to the

normal range (below +25 degrees). If the nosedown

pitch rate is insufficient, the nose stops its downward

motion and either begins to rise or stabilizes.

Promptly reapply the full aft stick command when the

nose reverses or after 23 seconds if reversal is not

apparent. Holding full forward stick more than 23

seconds with the nose stabilized can generate a rapid

yaw rate and delay recovery. If the aircraft has not

recovered after 23 seconds or if a yaw rate develops,

reapply full aft stick and complete another inphase

pitch rocking cycle.
Just prior to breaking the deep stall, the nosedown

pitch rate may decrease or even stop. Unless the nose

either definitely starts back up or stabilizes for longer

than 23 seconds, another pitchup cycle should not be

started. On the pitchdown cycle, the stick should be

held full forward (upright) or aft (inverted) while the

nose hesitates as the stall breaks. Following a short

hesitation (less than 23 seconds), the nose continues

down to near vertical. There is frequently a distinct, low

magnitude airframe shudder which occurs as the stall

is breaking. This shudder is a favorable indication that

recovery is occurring.
Once the deep stall is broken, aggressive pilot

commands are usually required to stop the pitch rate in

a steep dive. If possible, find and track a feature on the

ground. Maintain firm pressure on the MPO switch

until airspeed reaches 200 knots. If a transition to an

opposite AOA deep stall does occur, reinforce the

already present pitch motion with the MPO still

engaged and recovery should be rapid. Transitions

during upright deep stall recoveries are most likely to

occur with 370gallon fuel tank configurations.

Recovery to controlled flight is recognized by a steep

pitch attitude (usually within 30 degrees of vertical),

pitch rate stopping, and AOA in the normal range (-5

to +25 degrees). As airspeed increases above 200

knots, release the MPO switch, maintain neutral roll

and yaw commands, and recover from the resulting

dive.

Stick commands during pitch rocking should be

abrupt and full command, and should reverse after

pitch motion reverses. Stick commands that are not

abrupt and full command may not be effective. Rapid

fore and aft cycling of the stick out of phase with the

aircraft motion is also not effective.

T.O. GR1F16CJ1

612

The number of pitch rocking cycles required for

recovery from an upright deep stall is dependent on

aircraft configuration. Generally, recovery occurs in

one or two pitch rocking cycles. However, configura

tions with a centerline store (particularly a

300gallon fuel tank) or with 370gallon fuel tanks

may require more pitch rocking cycles for recovery.

These loadings usually have more oscillatory deep

stalls, and the roll and yaw motions make it more

difficult to determine proper stick cycling. Pitch

attitude is still the best indication for proper stick

cycling.

During upright deep stalls with a centerline store,

particularly a 300gallon fuel tank, the aircraft tends

to roll and yaw right while pitching up, and roll and

yaw left while pitching down. During deep stalls with

370gallon fuel tanks, the aircraft nose motion

appears triangular. This motion is characterized by a

roll and yaw right while pitching up, followed by a

pitch down, a hesitation, and a yaw to the left. These

alternating yaw oscillations should not be confused

with a sustained yaw rotation in one direction

indicating the aircraft is in a spin.

An inverted deep stall recovery is similar to an

upright recovery. In an inverted deep stall, the yaw

rate limiter automatically provides rudder against

the yaw rate. Pilot roll and rudder commands should

be avoided. Pilot roll and rudder commands are

inhibited when the MPO switch is in OVRD. Yaw

oscillations may be noticed but do not affect recovery.

To recover from an inverted deep stall, position the

MPO switch to OVRD and begin stick cycling

inphase with pitch motions. If no pitch motions are

apparent, make the first pitch input away from the

ground by pushing full forward and monitor pitch

motion. One or two pitch rocking cycles are usually

sufficient to recover from an inverted deep stall.

During recovery from an inverted deep stall, a

transition to an upright deep stall is likely to occur if

large pitch motions are present during inverted pitch

rocking and the MPO switch is released too early.

Early release of the MPO switch reduces the

horizontal tail authority available and delays

recovery. The MPO switch must be held in the OVRD

position until the deep stall is positively broken as

evidenced by the pitch rate stopping, AOA in normal

range (-5 to +25 degrees), and a steep pitch attitude

(usually within 30 degrees of the vertical). As

airspeed increases above 200 knots, release the MPO

switch, maintain neutral roll and yaw commands,

and recover from the resulting dive.

NOTE

129

GE

 The aircraft has demonstrated

a strong tendency to transition to an

upright deep stall during recovery

from an inverted deep stall. Aggres

sive pilot commands (full forward

stick) are required as the nose pitches

down to the vertical during recovery to

preclude a transition.

Spin Recovery

To recover from a spin, yaw rate must be stopped or

minimized before the aircraft can be recovered. Due

to large noseup moments caused by the inertial

properties of the aircraft and decreased horizontal

tail pitch effectiveness with sideslip, attempts to

pitch rock out of a spin are usually not effective. Pitch

rocking during a spin is also likely to aggravate roll

and yaw oscillations, which make recovery more

difficult.

The large forward g (eyeballs out) and sideforces

present during the initial portion of an upright spin

decrease noticeably as yaw rate decreases, which may

give the sensation that yaw rate is lower than it

actually is. Use outside references to determine when

the yaw rotation has stopped. Pitch rocking should

not begin until the yaw rotation stops or is minimized.

Pitch rocking with a steady yaw rate greater than 30

degrees per second may prevent recovery.

Waiting for yaw rotation to stop or minimize may

require from 20 to 30 seconds. When the yaw rotation

stops or is minimized, the aircraft will either

selfrecover or will settle into an upright deep stall. If

recovery is not apparent after yaw rate has stopped or

is minimized, perform the appropriate recovery

procedures described in the Deep Stall Recovery

section.

Pitch, roll, and yaw oscillations associated with a

deep stall should not be confused with the continuous

yaw rotation associated with a spin. Once the

continuous yaw rotation of a spin has been arrested

and pitch rocking has begun, pitch rocking should

continue until a recovery is achieved.

Upright spins with CAT III loadings that have large

lateral asymmetries from airtosurface stores may

be fast, flat, and possibly unrecoverable. There is an

option to jettison an asymmetric store as a last ditch

effort in case of a fast, flat spin. However,

aircraftstore collision may occur.

Inverted spins with CAT I loadings are effectively

prevented by the yaw rate limiter. The yaw rate limiter

automatically provides rudder against the yaw rate.

Pilot roll and rudder commands should be avoided.

T.O. GR1F16CJ1

613

If recovery is not apparent after yaw rate has stopped

or is minimized in an inverted spin, the aircraft has

settled into an inverted deep stall. Perform the

inverted deep stall recovery procedures.

ENGINE OPERATION DURING DEPARTURES/

OUTOFCONTROL

PW 229

 Departures at high altitude may result in an

engine stall. If in AB during an outofcontrol

situation, retard the throttle to MIL. If at MIL or

below, do not move the throttle. Do not advance the

throttle until beginning the dive recovery.

129

GE

 Departures at high altitude may result in an

engine stall. Prolonged negative g flight at a high

engine thrust level may result in an engine bearing

failure. Retard the throttle to IDLE after a

departure. Do not advance the throttle until

beginning the dive recovery.

If the engine stalls during a departure or

outofcontrol situation, refer to ENGINE STALLS,

Section III, after recovery is complete. The engine

should be left running during an outofcontrol

situation to insure adequate hydraulic pressure to

flight control surfaces for recovery. Recover from the

outofcontrol condition; then concentrate on the

engine. If the engine does not recover, it must be shut

down and restarted.

DEGRADED FLIGHT CONTROLS

FLCS DBU

Flight characteristics for cruise and landing are not

significantly affected by operation in DBU.

Although airspeed should be maintained below 500

knots/0.9 mach while in DBU, transitions to DBU at

higher airspeeds do not produce adverse handling

characteristics. Minimal pitch transients occur if

transition to DBU occurs at 1g. At higher g levels,

transition to DBU is accompanied by an initial

reduction in g. If the aft stick input is continued, g

level again increases, but may be less than that

which was available prior to the transition. The

STORES CONFIG switch is inoperative in DBU and

AOA/g force available is similar to that in CAT III.

If LG are lowered below 200 knots, a mild noseup

transient of approximately 2 degrees occurs. A

similar nosedown movement occurs if LG is raised

below 200 knots.

If an automatic transition to DBU occurs when in

auto TF, the FLCS initiates a 3g incremental no roll

to wings level fly up. This fly up can be interrupted

using the paddle switch. All ATF indications are

turned off (active light, TF FAIL warning light, ATF

NOT ENGAGED caution light, and autopilot PITCH

switch). HUD TF symbology is also removed.

LEADING EDGE FLAPS LOCKED (SYMMETRIC)

Flight characteristics for landing and low AOA

maneuvering are not significantly affected by

locked LEF's. At high airspeeds, LEF's locked down

cause increased buffet. At high AOA, LEF's locked

up reduce stability, increase departure susceptibil

ity significantly, and cause increased buffet. Above

1618 degrees AOA, an abrupt yaw departure may

occur, producing an uncommanded roll with little or

no forewarning. Do not exceed 12 degrees AOA with

the LEF's inoperative. Locked down LEF's signifi

cantly reduce cruise range. During landing,

floating may also be noticeable if LEF's are locked

at or near full down. The aircraft may float, sink

rate may decrease, and a slight forward stick

pressure may be needed to fly through the ground

effect.

STANDBY GAINS

When operating on standby gains, aircraft response

is normal at low AOA. Because the LEF's are at zero

degrees (LG handle in UP and ALT FLAPS switch in

NORM) with a dual air data failure, buffet and

departure susceptibility will be increased at higher

AOA (above 18 degrees). At flight conditions

higher/slower than the fixed gain conditions,

aircraft response is more sluggish requiring larger

control commands for a given response. Landing the

aircraft should present no special problems.

ONE HYDRAULIC SYSTEM

Flight characteristics with one hydraulic system

should be normal unless extremely large, rapid

control surface deflections are commanded. Under

these conditions, the hydraulic flow rate from the

one system may be inadequate which slows down

control surface movement rates and possibly causes

sluggish aircraft response.

SPEEDBRAKES

Speedbrakes may stick fully open or open

asymmetrically. If a yawing moment is noted when

the speedbrakes are opened, close the speedbrakes.

If the speedbrakes fail to close, a significant

increase in drag results. Fully opened speedbrakes

significantly reduce cruise range.

T.O. GR1F16CJ1

614

AIRCRAFT DAMAGE

Procedures for recovery of an aircraft with damage

will depend on the type and extent of the damage.

The following paragraphs provide general informa

tion based on analysis of past mishaps.

HORIZONTAL TAIL

Loss or partial loss of one horizontal tail surface will

not result in an uncontrollable aircraft except for

certain combinations of flight conditions (mach

greater than 0.80 and altitude less than 15,000 feet),

aircraft loading (heavy CAT III), and CG at or near the

aft limit. Avoid abrupt maneuvering and maintain

airspeed between 200 and 300 knots until landing

approach. Place the STORES CONFIG switch to CAT

III if in CAT I. Some roll stick or roll trim may be

required to maintain wings level. Use a maximum of

11 degrees AOA during final approach. After

touchdown, lower nose to runway as soon as practical.

FLAPERON

Separation of a flaperon from the wing (flaperon still

attached to the ISA in the fuselage) causes the

outboard end of the flaperon surface to rotate

upwards, towards the fuselage. This may be

accompanied by a roll transient. Adequate roll stick

authority should be available to counter the effect and

maintain control. With a flaperon surface separated

from one wing, landing should be made without

extending the TEF on the other wing (use alternate

landing gear extension, leave LG handle UP, and

select brakes CHAN 2). Hydraulic system pressures

should also be monitored. Upward rotation of a

separatedfromthewing flaperon surface has caused

ISA movement that resulted in a leakage failure of

hydraulic system A.

RUDDER AND VENTRAL FINS

Loss or partial loss of the rudder or a ventral fin will

not result in controllability problems unless the

aircraft is above 1.5 mach. If loss or partial loss of the

rudder or a ventral fin occurs, avoid abrupt

maneuvering and reduce speed to subsonic, if

supersonic. Place the STORES CONFIG switch to

CAT III if in CAT I. During landing with loss or partial

loss of the rudder, lower the nose to the runway as

soon as practical so that NWS can be used as required

for directional control.

LEADING EDGE FLAPS

Damage to the LEF's may result in locked LEF's. If

the LEF's have not automatically locked, they should

be manually locked. Refer to Leading Edge Flaps

Locked (Symmetric), this section for a discussion of

flight characteristics.

WING

Loss of a portion of the wing produces a rolling motion

towards the damaged wing. The capability to stop this

roll depends on airspeed, g, and the amount of wing

surface lost. Higher airspeeds (above 250 knots) and

low g (less than 2) are essential for maximizing the

amount of roll control authority available. If the

aircraft is in a dive when a portion of the wing surface

is lost, apply roll stick force to stabilize the aircraft in

roll before applying g to recover from the dive

(altitude permitting). Use the lowest g level practical

to recover from the dive. As g is increased, additional

roll stick force is required to maintain wings level.

Depending on the amount of wing surface lost, the

minimum speed to maintain adequate roll control

could be well above 200 knots.

RADOME

Loss of the radome results in loss of two air data

sources (pitot probe) and two AOA sources (AOA

transmitters); however, loss of the radome does not

necessarily cause the aircraft to be uncontrollable.

FOD to the engine and other damage to the aircraft

may also occur as the radome departs.

Loss of two air data sources will affect handling

qualities. If the two airspeed sources from the pitot

probe go to erroneously low values at the same time,

the remaining good source from the fuselage air data

probe will be considered failed (i.e. a single failure).

In this case the FLCS will not switch to standby

gains. Gain scheduling will be based on the

erroneously low airspeed; thus, the aircraft will

become increasingly pitch sensitive as airspeed is

increased. If the two airspeed sources are lost in a

manner that the FLCS recognizes as two failures,

then the FLCS reverts to standby gains. In standby

gains, the opposite problem occurs. With the landing

gear up at slow speeds, the aircraft will be sluggish

compared to handling qualities prior to the radome

loss. It may seem as though the aircraft isn't

responding to stick inputs if sufficient response time

is not allowed.

Loss of two AOA sources may not be detected as a dual

failure. The end result to the FLCS is an AOA in the

range of 11-13.6 degrees (i.e. no AOA limiter).

T.O. GR1F16CJ1

615

If the radome is lost, attempt to attain 1 g level flight

at 275-300 knots and place the landing gear handle

down. Airspeed and AOA indications won't be

accurate. Use a chase aircraft to help establish speed

and keep AOA below 12 degrees. Assess the situation

by determining what failures are being annunciated

and perform a controllability check.

DIVE RECOVERY

Refer to figure 61. Dive recovery capability is given

as altitude lost during pullout and is a function of

pullout load factor, dive angle, true airspeed, and

FLCS limiting. Plots to convert indicated airspeed

or mach number into true airspeed are provided on

the chart. Dive recovery during constant load factor

pullout may be on the AOA limiter prior to recovery,

under certain initial conditions, as airspeed is

reduced. Dive recovery capability at constant load

factor is nearly independent of store drag. The dive

recovery chart is applicable to GW's between

20,000 30,000 pounds. The dive recovery chart

becomes increasingly conservative for GW's less

than 25,000 pounds and decreasingly conservative

for GW's greater than 25,000 pounds. Increase

altitude lost during full aft stick pullout by 4

percent for each 1000 pounds in excess of 25,000

pounds GW if initial dive angle is 

w

45 degrees and

initial airspeed is less than 500 knots.
For a constant g pullout, use the greater of constant

g or limiter pullout altitude lost.

NOTE

The dive recovery chart is based on an

idle thrust, wings level, speedbrakes

fully open recovery. However, if air

speed is below 350 knots, altitude loss

is minimized by selecting/maintaining

MIL/AB thrust and closing speed

brakes. If airspeed is 350 knots or

above, selecting/maintaining idle

thrust and opening speedbrakes mini

mize altitude loss. In either case, best

dive recovery performance is obtained

by making an ADI referenced wings

level pull.

SAMPLE PROBLEM:

S

GW

= 25,000 pounds

A.

KIAS

= 300

B.

Initial altitude

= 15,000 feet

C.

Temperature

= 0

°

C

D.

KTAS

= 381

E.

Mach number

= 0.59

F.

Dive angle

= 60 degrees

G.

Category/KIAS

= CAT I/300

H. Altitude lost during

limiter pullout

= 2130 feet

I.

Altitude lost during
limiter pullout

= 2130 feet

J.

Maximum pullout load
factor available

= 5.8g

K.

Pullout load factor

= 3g

L.

Altitude lost during
3g pullout

= 4150 feet