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F16C/D (BLOCKS 50 AND 52+). FLIGHT MANUAL (15 OCTOBER 2002) - page 56

T.O. GR1F16CJ1

Change 1515/(516 blank)

Airspeed Limitations

(Systems)

SYSTEM OR CONDITION

KIAS/MACH

Canopy Open or in Transit

70 (includes

ground wind

velocity)

LG E t d d

i T

300/0.65, which

LG Extended or in Transit

300/0.65, which

ever is less

AR Door Opening/Closing

400/0.85, which

ever is less

AR Door Open

400/0.95, which

ever is less

Flight in Severe Turbulence

(+3g)

500

Drag Chute Deployment

170

Figure 56.

Acceleration

Limitations

LOAD FACTOR (g)

CONFIGURATION

SYMMETRIC ASYMMETRIC

TAKEOFF

+4 0 0 0

+2 0 0 0

LANDING

+4.0, 0.0

+2.0, 0.0

LG RETRACTION*

+2 0 0 0

LG EXTENSION

+2.0, 0.0

If the LG handle is raised near 2 g's approaching 300 knots, actua

tor power may be insufficient to completely retract the LG until g is
reduced.

Figure 57.

AOA and Rolling Limitations

CATEGORY

STORES

CONFIG

SWITCH

MAX AOA

MAX BANK ANGLE CHANGE FOR MAX ROLL MANEUVER

LIMITER

360

III

LIMITER

360

NOTES:

1. Determine loading category from the appropriate line in T.O. GR1F16CJ12, figure 510, Stores Limita

tions.

2. The roll command should be released in sufficient time to avoid overshooting the indicated bank angle change

limits.

Figure 58.

T.O. GR1F16CJ1

SECTION VI

FLIGHT CHARACTERISTICS

TABLE OF CONTENTS

Introduction

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Flight Control System

. . . . . . . . . . . . . . . . . . . . .

FLCS Limiters

. . . . . . . . . . . . . . . . . . . . . . . . . .

Leading Edge Flaps

. . . . . . . . . . . . . . . . . . . . .

Speedbrakes

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Autopilot

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Trim

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Normal Flight Characteristics

. . . . . . . . . . . . . .

Category I Loadings

. . . . . . . . . . . . . . . . . . . . .

Category III Loadings

. . . . . . . . . . . . . . . . . . .

Conformal Fuel Tanks

PX III

. . . . . . . . . . . . .

Flight With LG Down

. . . . . . . . . . . . . . . . . . . .

Landing Configuration

. . . . . . . . . . . . . . . . . .

Factors Affecting Flying Characteristics

. . . . .

CenterofGravity Considerations

. . . . . . . . .

Effect of Thrust

. . . . . . . . . . . . . . . . . . . . . . . . .

Effect of Low Airspeed Maneuvering

. . . . . .

High Pitch, Low Airspeed

. . . . . . . . . . . . . . . .

Flight With Stores

. . . . . . . . . . . . . . . . . . . . . .

Limit Cycle Oscillation and

Aeroservoelastic Oscillation

. . . . . . . . . . . .

Asymmetric Loadings

. . . . . . . . . . . . . . . . . . .

Store Separation

. . . . . . . . . . . . . . . . . . . . . . . .

OutofControl Characteristics

. . . . . . . . . . . . . .

Yaw Departure

. . . . . . . . . . . . . . . . . . . . . . . . . .

Pitch Departure

. . . . . . . . . . . . . . . . . . . . . . . . .

Deep Stall

610

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Spin

610

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Recoveries

611

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SelfRecovery

611

. . . . . . . . . . . . . . . . . . . . . . . . .

Deep Stall Recovery

611

. . . . . . . . . . . . . . . . . . .

Spin Recovery

612

. . . . . . . . . . . . . . . . . . . . . . . .

Engine Operation During Departures/

OutofControl

613

. . . . . . . . . . . . . . . . . . . . . . . .

Degraded Flight Controls

613

. . . . . . . . . . . . . . . . . .

FLCS DBU

613

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Leading Edge Flaps Locked

(Symmetric)

613

. . . . . . . . . . . . . . . . . . . . . . . . . .

Standby Gains

613

. . . . . . . . . . . . . . . . . . . . . . . . . .

One Hydraulic System

613

. . . . . . . . . . . . . . . . . . .

Speedbrakes

613

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Aircraft Damage

614

. . . . . . . . . . . . . . . . . . . . . . . . . . .

Horizontal Tail

614

. . . . . . . . . . . . . . . . . . . . . . . . . .

Flaperon

614

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rudder and Ventral Fins

614

. . . . . . . . . . . . . . . . .

Leading Edge Flaps

614

. . . . . . . . . . . . . . . . . . . . .

Wing

614

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radome

614

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dive Recovery

615

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

INTRODUCTION

Information presented in this section reflects the

flight characteristics with category I and III

loadings. Refer to AOA AND ROLLING LIMITA

TIONS, Section V, for information regarding specific

categories.

FLIGHT CONTROL SYSTEM

The FLCS is a fourchannel flybywire system. The

FLCC combines pilot commands along with aircraft

motion and flight conditions to command position of

the flight control surfaces. Artificial stability

provided by the FLCS allows for relaxed static

stability which increases performance and maneu

verability by reducing trim drag and increasing

maximum lift. Refer to FLIGHT CONTROL

SYSTEM, Section I.

FLCS LIMITERS

FLCS limiters may be defeated if maneuvering

limits are not strictly observed. Departure may

result from maximum maneuvering combined with

maximum permissible aft CG. The most critical

maneuvers are maximum command rolls coupled

with either maximum aft stick or exceeding the

maximum bank angle change limits.

The AOA/g limiter depends on the horizontal tails

to control g and AOA. If the airspeed decreases until

there is not enough airflow over the tails to provide

this control, the limiter is defeated and a departure

or deep stall may result. This condition may occur

in a nosehigh, decreasing speed maneuver. Refer to

LOW AIRSPEED OPERATING LIMITATIONS,

Section V.

LEADING EDGE FLAPS

The LEF system is designed to optimize wing airflow.

It also provides special functions in the takeoff and

landing configurations.

T.O. GR1F16CJ1

At subsonic speeds, the LEF's move from 2 degrees

up to 25 degrees down as a function of mach number,

AOA, and altitude. This automatic operation

significantly reduces buffet and drag and improves

high AOA directional stability. If the LEF's fail to

schedule properly during maneuvering flight,

higher than normal buffet levels occur and, in the

high AOA region, reduced directional and longitu

dinal stability may also be noted. At supersonic

speeds, the LEF's are scheduled to minimize drag.

SPEEDBRAKES

The speedbrakes provide deceleration over the

entire flight envelope. There are no trim changes

associated with speedbrake operation and induced

buffet is negligible. A yaw oscillation may occur at

approximately 1.4 mach with speedbrakes opened.

The oscillation is neutrally damped and no action is

required. The oscillation may be eliminated by

either closing the speedbrakes, reducing mach, or

increasing the g level.

AUTOPILOT

With the HDG SEL and ALT HOLD modes engaged,

the aircraft turns, climbs, or dives within the limits

of the autopilot to capture the heading reference

and the altitude reference regardless of aircraft

attitude. This autopilotcommanded flight may

eventually return the aircraft to a preselected

heading and altitude if airspeed and altitude

permit.

If the ALT HOLD remains engaged as airspeed

transits 1.0 mach, a mild pitch transient may occur

and can be eliminated by depressing the paddle

switch until the altimeter has stabilized.
Use of pitch altitude or attitude hold during

decelerating flight can produce either autopilot

disengagement and the FLCS A/P FAIL PFL or descent

from the referenced altitude if AOA increases above

certain values. In CAT I, the autopilot disengages and

the FLCS A/P FAIL PFL occurs when 15 degrees AOA

is exceeded. In CAT III, the aircraft starts descending

from the referenced altitude at approximately 810

degrees AOA. If the descent is not corrected within 5

seconds, the FLCS A/P DEGR PFL occurs.

Since the autopilot command is additive

to stick commands, use of ALT HOLD in

conjunction with high g maneuvering

may result in aircraft overg.

TRIM

The aircraft can be trimmed about all three axes.

With pitch trim centered in cruise gains and no

input to the stick, the aircraft attempts to maintain

1g flight regardless of flight condition unless AOA

exceeds 15 degrees. Full noseup/full nosedown trim

corresponds to +3.4g or -1.4g in cruise gains.

NOTE

Airspeed must be closely monitored

because there is little aerodynamic

indication of large changes in airspeed.

Cues which normally indicate airspeed

changes, such as stick movement or

trim changes, are absent.

Above 15 degrees, the FLCS commands an

increasing nosedown pitch attitude as a warning of

decreasing airspeed. A specific force applied to the

stick commands a specific g increment from the trim

condition. Moving the PITCH TRIM wheel changes

the handsoff trim condition.

In takeoff and landing gains, zero pitch trim

commands zero pitch rate until 10 degrees AOA. A

slight amount of noseup trim is required to zero

stick forces during an 1113 degree AOA approach.

When properly trimmed and no input is applied to

the stick, the aircraft attempts to maintain zero roll

rate. Moving the ROLL TRIM wheel changes the

handsoff trim condition. Maximum roll trim

authority is approximately onefifth of maximum

stick command of cruise gains. However, precise

trimming is difficult using the stick TRIM button.

Roll trim requirements may change with stores,

particularly at supersonic speeds. For asymmetric

configurations (asymmetrical stores or rudder

mistrim), roll retrimming may be required as

flight conditions change. Roll trim inputs also

command rudder deflection through the ARI. The

ARI switches out with wheel spinup upon landing.

Likewise, the ARI switches in following takeoff as

the wheels spin down. This switching may cause

abrupt rudder inputs to occur if roll (due to

asymmetries or crosswind) is being input via the

stick or trim.

Rudder trim inputs command rudder deflection.

Rudder trim is required with asymmetrical

configurations and frequently during supersonic

flight, especially with stores. Maximum trim

authority is 12 degrees.

T.O. GR1F16CJ1

NORMAL FLIGHT CHARACTERISTICS

The capability of the aircraft to rapidly

attain and sustain high g levels, which

may cause ginduced loss of conscious

ness, should be considered during

heavy maneuvering.

The FLCS provides constant response for specific

inputs regardless of flight conditions. Commanded

pitch responses are in g increments per stick force

for AOA below 15 degrees. Above 15 degrees AOA,

stick force increases as a cue of increasing AOA.

Conventional cues such as aircraft buffeting forces

are not always present as AOA and g limits are

approached. The commanded lateral response is

roll rate per stick force. Rudder position is

commanded by rudder pedal force.

The ARI provides coordinated rudder commands

and reduces sideslip during rolling maneuvers.

Additional pilot rudder commands do not improve

roll performance but do increase departure

susceptibility. When ARI is not available during

takeoff and landing (MLG wheel speed above 60

knots), pilot rudder commands may be required to

provide coordinated flight and to control yaw.

Rolling g limits are not protected by

the FLCS and must be observed.

CATEGORY I LOADINGS

The FLCS minimizes the possibility of departures or

spins. Roll rate inputs command flaperons and

horizontal tails for roll power to provide a relatively

constant roll response.

Maximum command 360degree rolls at subsonic

speeds may cause a slight g reduction on

termination. At supersonic speeds, maximum roll

rates may cause a slight increase in g. At high AOA

and low airspeed conditions, roll performance is

reduced by the FLCS to minimize pitch/roll coupling.

Aft CG's, open speedbrakes, asymmetric missiles, or

centerline stores decrease departure resistance.

CATEGORY III LOADINGS

Aircraft response with most category III loadings

remains similar to that of the clean aircraft;

however, large stores significantly increase total

aircraft drag and reduce performance. Light

buffeting may occur during level flight at approxi

mately 0.92 mach. In addition, surging may occur

near the store limit airspeed, especially at low

altitude. Neither condition requires specific action.

With STORES CONFIG switch in CAT III, the

AOA/g limiter provides departure resistance for all

category loadings. Except for the requirement to

avoid structural overstress, pilot workload is

reduced to a level comparable to that with category

I loadings.

CONFORMAL FUEL TANKS

PX III

In general, the presence of CFT's only minimally

affects flight characteristics. One item of signifi

cance is a reduction in directional stability which

manifests itself as higher angles of sideslip during

lateraldirectional maneuvering. Directional loose

ness" may be evident during tasks such as tracking

and aerial refueling.

LESS

b6n

Significantly higher angles of sideslip can be

generated with pilot rudder input. Rudder should be

used only as required. Avoid abrupt and/or large

inputs.

LESS

b6n

Maximum command and/or

abrupt pilot rudder inputs can result in

departure or structural overload when

CFT's are installed.

FLIGHT WITH LG DOWN

With the LG handle down, LG and TEF's are

extended and the FLCS operates in takeoff and

landing gains. Normally, this mode of flight is

limited to takeoff, approach, and landing; however,

circumstances can arise which require flight for an

extended distance with the LG down. If so, the LG

should be left pinned but the streamers should be

removed to prevent damage.

T.O. GR1F16CJ1

With the LG pins installed, it is preferable to raise

the LG handle once airborne. This action retracts the

TEF's and significantly reduces drag and the FLCS

switches to cruise gains. For cruise with only the LG

down, the best airspeed is 230250 knots. A clean

aircraft can be flown at 25,00030,000 feet with the

LG down and TEF's up and fuel flow is 30003400

pph. If the LG handle is left down, the TEF's remain

down and the best cruise altitude is less than 20,000

feet with significantly higher fuel flows.

LANDING CONFIGURATION

Two distinct techniques may be used when landing.

One technique is to trim for approximately 11

degrees AOA and to fly that airspeed throughout

the final approach. Attitude/glidepath is controlled

by the stick, and airspeed/AOA is controlled by the

throttle. This technique allows better pitch control,

better overthenose visibility, and a more stable

HUD presentation. In gusty wind conditions, the

aircraft wallows less, and during the flare, the sink

rate is easier to control. The aircraft floats

approximately 8001200 feet from flare initiation to

touchdown. Another technique is to trim for 13

degrees AOA and to fly that airspeed throughout

the final approach. The throttle is used primarily to

control glidepath, and the stick controls airspeed

through control of AOA and direction through bank

angle. This type of approach primarily allows better

control of touchdown point and more efficient

energy dissipation; however, since the aircraft is

already at 13 degrees AOA, the flare is more

difficult, and care must be exercised to avoid

scraping the speedbrakes or landing firm. The

aircraft floats approximately 500700 feet from

flare initiation to touchdown.

Regardless of the technique used, establish

computed final approach airspeed for the desired

AOA early on final and trim the aircraft. Airspeed

changes result in pitch changes, which may require

retrimming and make glidepath control more

difficult.

PW 229

Small throttle adjustments may be

required as the DEEC retrims the engine.

On short final, avoid premature or large thrust

reductions which may cause increased sink rates and

a hard landing. Use thrust rather than back stick to

control undesirable sink rates. Increased back stick

may result in a tail strike in this situation. AOA

decreases slightly as the aircraft enters ground effect.

All normal landings should be made with speed

brakes opened to the 43degree position to avoid a

floating tendency when entering ground effect. A

touchdown at the desired point at 13 degrees AOA can

be achieved when flying final at either 11 or 13

degrees AOA by adjusting the initial aimpoint.

Increased control inputs to achieve normal aircraft

response as airspeed decreases are unnecessary.

Control inputs should be kept small to avoid

overcontrol.

Due to the aircraft light wing loading and the

floating tendency associated with ground effect,

wake turbulence on final approach and during

touchdown presents a significant hazard.

Increased spacing between landing aircraft should

be used when there is little or no effective

crosswind. Exercise caution and be ready to initiate

a goaround when wake turbulence is encountered.

An early goaround decision may help avoid the

need for a large roll control input. Such an input

retracts a flaperon, causing decreased lift and

possibly a sink rate as well as a roll. A large roll

input at slow airspeed also causes a large horizontal

tail split. A horizontal tail surface could contact the

runway while trying to counter wake turbulence

effects during touchdown.

If pitch trim is used during the turn to final, forward

stick/trim will be required upon rollout on final

approach to counter noseup motion. Floating

tendencies following a high flare or aircraft bounce

may be increased. Slight forward stick force may be

required to prevent a long or slow landing. Stick

force per degree AOA change is reduced and should

not be relied upon as a slow speed cue.

FACTORS AFFECTING FLYING CHAR

ACTERISTICS

NOTE

Pitch sensitivity and pilot induced

oscillations (a maximum of

0.5g)

may occur above 0.80 mach when

flying with 600gallon fuel tanks. This

behavior can be minimized by avoiding

large pitchstick inputs and rapid

pitchstick reversal. If this behavior

becomes objectionable, reduce air

speed and pitchstick inputs.

T.O. GR1F16CJ1

NOTE

Momentary uncommanded pitch

changes (a maximum increase of 1g)

and/or bank angle changes (a maxi

mum increase of 15 degrees) may occur

above 0.85 mach when flying with

600gallon fuel tanks. This behavior is

known to occur with loaded TER racks

but may occur with other store

loadings. Avoid overresponding to the

changes and use smooth stick input to

minimize pilot induced oscillations.

Airspeed should be reduced if this

behavior becomes objectionable. If

flying within normal load factor

carriage (MAX ACCEL G) limits

defined in T.O. GR1F16CJ12,

STORES LIMITATIONS, an incre

mental 1g uncommanded pitch change

will not exceed structural limits.

A mild pitch oscillation (a maximum of

0.15g at 3 cycles per second) may

occur at 0.750.90 mach while in cruise

gains or at 330400 knots while in

takeoff and landing gains. The oscilla

tion is caused by the normal response

of the aircraft and FLCS and does not

cause a significant tracking problem.

Momentary roll hesitations may

occur when commanding low to

moderate roll rates (generally less

than 100 degrees per second) when

airspeed is above 350 knots, and

altitude is 20,000 feet or less. This

behavior is most noticeable when

flying without stores.

A short duration (less than 3 seconds)

series of rapid wing rocks (less than

10 degrees of bank angle change) may

occur when terminating a high roll

rate maneuver at airspeeds above 400

knots. This behavior is most notice

able when flying without stores.

Minor AOA oscillations (less than

degrees) may be noticed during ele

vatedg maneuvering on or near the

AOA/g limiter with certain loadings.

This behavior is most noticeable

between 250 and 350 knots when

flying above 25,000 feet MSL.

Momentary roll hesitations may occur

during elevatedg maneuvering on or

near the AOA/g limiter with certain

loadings. This behavior is most notice

able between 250 and 350 knots when

flying above 25,000 feet MSL.

CENTEROFGRAVITY CONSIDERATIONS

Monitoring the forward and aft fuel distribution

provides an indication of the aircraft CG.

As CG moves aft, higher pitch rates are obtainable

and susceptibility to departure and deep stall

increases.

NOTE

The most aft CG occurs with

approximately 2000 pounds of internal

fuel remaining.

With external fuel tanks, the most

aft CG occurs when the external fuel

tanks have just emptied.

EFFECT OF THRUST

Thrust changes result in little or no change in

aircraft trim or stability at all operational load

factors and for all store loadings.

EFFECT OF LOW AIRSPEED MANEUVERING

Departures are possible at low airspeeds and low

pitch angles if large, simultaneous pitch and roll

inputs are made.

The FLCS requires adequate airflow over the

control surfaces to be effective, which means that

airspeed is a critical factor in departure susceptibil

ity during maneuvering. Low airspeeds should,

therefore, be avoided during maximum perfor

mance maneuvering.

FLCS limiters can be defeated at low

airspeeds (below 200 knots in a CAT I

configuration) during maximum pitch

and roll commands initiated from

below limiter AOA's.

The aircraft can be departed (from

parameters outside the tone on area of

figure 142) with no low airspeed warning

tone present, if abrupt or uncoordinated

FLCS commands are made.

T.O. GR1F16CJ1

HIGH PITCH, LOW AIRSPEED

The low airspeed warning tone sounds to aid in

recognizing that critical high pitch, low airspeed

flight conditions are reached.

Proper assessment of flight path angle

(not pitch angle) is key to determining

the nearest horizon and performing a

proper recovery. Differences between

flight path and pitch angle of up to 25

degrees, combined with the visual

illusion caused by a reclined seat can

lead to an incorrect decision to

continue the maneuver through the

vertical. The risk of a departure/deep

stall in this instance is very high.

Avoiding a departure under these conditions requires

specific control techniques. To recover, first release

aft stick pressure. This action unloads the aircraft

and reduces AOA so that the flightpath more closely

coincides with the longitudinal axis of the aircraft.

Smoothly roll inverted to the nearest horizon. After

the roll, smoothly apply the aft stick pressure

required to keep the nose moving toward the horizon.

As airspeed continues to decrease during the

recovery, more aft stick pressure may be required to

keep the nose moving. Continue to smoothly increase

aft stick pressure up to the AOA/g limiter. If full aft

stick is inadvertently released, do not reapply it

unless required to keep the nose moving.

Avoid large, simultaneous pitch and

roll commands to preclude a roll

coupled departure. Small lateral com

mands can be made as required to

maintain wings level, inverted flight.

Do not abruptly apply aft stick pressure

at anytime during the recovery. Rapid

aft stick pressure will generate exces

sive AOA, overshooting the AOA

limiter and causing departure.

During a recovery where full aft stick is required,

nose movement toward the horizon may slow down

markedly as the AOA/g limiter tries to limit AOA.

As long as the nose continues to move, no further

action is required. If the nose of the aircraft does not

continue to move toward the horizon, the aircraft

has departed, and outofcontrol recovery proce

dures should be initiated.

After attaining a nosedown attitude with airspeed

increasing, continue to avoid abrupt commands.

The aircraft may either be unloaded and rolled

upright or a splits recovery can be made at airspeed

above 200 knots, altitude permitting, before

continuing to maneuver. The splits recovery is the

simplest way to recover the aircraft. However, if

altitude is a factor, allow airspeed to increase to a

minimum of 150 knots, unload the aircraft to less

than 1g, smoothly roll upright, and recover to level

flight.

FLIGHT WITH STORES

The major effects of stores are increased weight and

inertia. A reduction in aircraft response and

damping should be expected as GW increases,

particularly when stores are carried. Stores

generally reduce longitudinal and directional

stability and increase inertial effects so that the

pilot must anticipate initiation and termination of

maneuvers based on the loadings. High roll and

pitch rates are attainable with full force application

of the stick. Avoid abrupt control commands which

may cause AOA overshoots in excess of the

limitations specified in Section V and T.O.

GR1F16CJ12.

Bank angle change limits must not be exceeded.

During rolling maneuvers with category III

loadings, the roll rate must be stopped prior to

360degree bank angle change. Removing the roll

input is not always sufficient (opposite stick may be

required). Refer to STORES LIMITATIONS, T.O.

GR1F16CJ12, for carriage limits.

Certain store loadings may exhibit decreased

yaw/roll damping in supersonic flight and result in

mild yawing oscillations. Neutral and divergent

yaw and roll oscillations may occur during sideslip

maneuvers at supersonic airspeed. These oscilla

tions are aggravated when large stores are carried.

Excessive vertical tail loads may be generated if

oscillations become sufficiently large. If oscillations

are encountered during rudder commands, release

the rudder input. Additionally, buffeting may occur

in transonic flight with certain store loadings.

NOTE

A mild airframe vibration may be

experienced while supersonic when

carrying a centerline store.

T.O. GR1F16CJ1

LIMIT CYCLE OSCILLATION AND AEROSERVO

ELASTIC OSCILLATION

A limited amplitude constant frequency oscillation

(commonly referred to as limit cycle oscillation or

LCO) may occur with certain stores loadings. The

LCO (typically 510 cycles per second) may occur in

level flight or during elevated g maneuvers. The

LCO may appear as buffeting or turbulence similar

to that experienced during normal transonic buffet,

but the buffeting is a constant frequency, lateral

acceleration from sidetoside or, in some cases,

vertical accelerations up and down. The magnitude

generally increases with increasing airspeed and/or

load factor. Other cues of LCO include significant

vertical movement of the forward area of wing

stores, especially wingtip launchers and missiles;

this motion is typically up and down, but may also

follow a circular pattern. In addition, cockpit

instruments may become difficult to read as the

LCO amplitude increases from moderate to severe.

Within published carriage limits, LCO is not

detrimental to the aircraft. LCO susceptible

loadings include airtosurface and airtoair

loadings and associated downloadings. If LCO is

encountered and is uncomfortable or distracting,

reduce airspeed and/or load factor. Refer to

STORES LIMITATIONS, T.O. GR1F16CJ12, for

carriage limits.

An aeroservoelastic (ASE) oscillation is similar to

LCO. Wing and store oscillation and cockpit

vibration may be indistinguishable from those

caused by LCO. However, ASE oscillation is driven

by the FLCS, resulting in key differences. ASE

oscillation (typically at 45 cycles per second) is

most likely to occur within a narrow range between

0.9 and 0.95 mach. The magnitude is strongly

dependent on mach, but not strongly dependent on

load factor, and increases in severity as altitude

decreases. ASE oscillation will probably occur when

carrying wingtip AIM120 missiles. The presence of

stores at stations 3 and/or 7 may dampen the

oscillation. Within published carriage limits, ASE

oscillation is not detrimental to the aircraft. If ASE

oscillation is encountered and is uncomfortable or

distracting, change airspeed by at least 0.05 mach.

NOTE

LCO and ASE oscillation may be

indistinguishable to the pilot. Either

may produce severe oscillation at the

most critical flight condition. While

not detrimental to the aircraft within

published carriage limits, the motions

may be extremely uncomfortable or

impact mission accomplishment. The

most effective way to reduce LCO or

ASE is to reduce airspeed.

ASYMMETRIC LOADINGS

If roll trim is used to hold up a heavy wing, the ARI

adds rudder in the direction of the roll trim, causing

a yaw away from the heavy wing. If roll trim is used

for takeoff, yaw occurs when the wheel speed drops

below 60 knots groundspeed after takeoff, activat

ing the ARI. This yaw is easily controllable by

rudder commands. Yaw and roll trim requirements

change for different flight conditions.

Asymmetric loads increase departure and spin

susceptibility. Roll commands/trim away from the

heavy wing is required to maintain the desired roll

attitude. Increasing g requires additional roll

commands/trim. Therefore, aft stick commands

result in increased roll requirements which, in

turn, produce yaw away from the heavy wing due to

ARI action.

With certain asymmetric category III

loadings (2000 pounds or greater on

station 3 or 7 with stores on stations 4,

6, and/or 5), rapid or abrupt aft stick

commands may result in sudden nose

slicing departures.

Departure with an asymmetric cate

gory III loading may result in a fast,

flat (possibly nonrecoverable) spin.

NOTE

Leftwing heavy asymmetries are

more susceptible to departure.

During TF, commanded flyups with asymmetric

loads result in a slower roll to wings level away from

the heavy wing. Stick inputs to assist the roll to wings

level may be required as described in T.O.

GR1F16CJ3411

At high airspeeds, asymmetric loads exhibit some

unusual flight characteristics. Frequent trim

reversals may occur during supersonic accelera

tion. At airspeeds greater than 700 knots, yaw

oscillation may occur with significant lateral

accelerations.

Over 750 knots, a high frequency directional

shaking may occur with loadings such as the ECM

pod.

Content .. 54 55 56 57 ..

F16C/D (BLOCKS 50 AND 52+). FLIGHT MANUAL (15 OCTOBER 2002) - page 56

F16C/D (BLOCKS 50 AND 52+). FLIGHT MANUAL (15 OCTOBER 2002) - page 56