1、 SAE AIRm11094 90 M 83573qO 0051018 5 AEROSPACE INFORMATION mEngineering*W For Advancing Mobility -Land Sea Air and Space INTENATIONA 400 Commonweatih Drive, Warrendale, PA 15096-0001 REPORT Submitted for recognition as an American National Standard Sm AIR4094 Is sued 1990-05 AIRCRAFT FLIGHT CONTROL
2、 SYSTEMS DESCRIPTIONS 1. 2. 3, 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 TAB E OF CONTENTS SCOPE . PURPOSE . GENERAL . Fairchild Republic A-10 Thunderbolt II Fairchi Id Republ i c T-46 . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . General Dynamics F-111 . . . . . . . . ,
3、 . . . , . . . . . . . . . . . . . . , . . . . . . . . . , . . General Dynamics F-16 Falcon Grummnn A-6E Intruder . Grumman F-14 Tomcat .*4t.1 l.,., Grumman X-29A . McDonnell-Douglas AV-8 Harrier II . McDonnell-Douglas F-15 Eagle McDonnell-Douglas FIA-18 Hornet I.I,. 2 2 2 2 9 14 19 23 30 35 40 45 5
4、1 SAE Technical Board Rules provide that: This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely VOlUntafy, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is th
5、e sole responsibility of the user.“ SAE reviews each technical report at least eveiy five years at which time it may be reaffirmed, revised, or cancelled. SA invites your writien comments and suggestions. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction
6、 or networking permitted without license from IHS-,-SAE AIRmY044 40 8357340 0051014 7 W *e AIR4094 1. SCOPE: This Aerospace Information Report (AIR) supplies information on the flight control systems incorporated on various aircraft. aircraft is followed by a description of the flight control system
7、, some specific components, drawings of the internal arrangement, block diagrams, and schematics. System operation redundancy management is also presented. A brief description of the 2. PURPOSE: The purpose of this document is to provide system description information on various aircraft flight cont
8、rol systems. 3. GENERAL: 3.1 Fairchild Republic A-10 Thunderbolt II: The Fairchild Republic A-10 Thunderbolt II (Figure 1) is a twin engine close air support attack aircraft. The surfaces used to effect pitch, roll, and yaw are the traditional elevators, ailerons, and rudders which are controlled by
9、 a mechanical primary flight control system (Figure 2). 3.1.1 System Description: The flight control system is a type III irreversible power control which reverts to type I (reversible mechanical control system) with the loss of both hydraulic systems. system will still retain full powered control r
10、esponse. Loss of both systems automatically engages the manual reversion mode that has performance for moderate maneuvers and safe landings. The linkages consist of push-pull rods, cables and cranks configured for straight parallel paths with low friction and minimum connections (Figure 2). Artifici
11、al feel is provided by redundant spring/cam devices located at each surface actuator. Redundant stabi 1 i ty augmentation systems (SAS) are provided to enhance tracking and minimize trim transients for speed brake deployment in pitch, and to reduce sideslip in yaw during abrupt roll maneuvers. The r
12、oll axis does not employ a SAS. Redundant pilot control capability is provided through separate transmission paths for the pitch, roll, and yaw commands. In addition, the elevators and rudders have dual control surfaces and actuators while the ailerons are equipped with tandem hydraul i c actuators.
13、 Loss of either hydraulic 3.1.2 System Mechanization: The pitch control is effected with two independent elevators. Pitch linkage separates into extreme left and right parallelogram cable and linkage transmission paths (Figure 3). system drives independent hydraulic actuators attached to the left an
14、d right elevators. elevators for uniform displacement is provided with prescribed torsional stiffness and 12 blind rivets which fail in the event of a jam of one of the elevators. Electrically operated pitch control disconnectors, which normally function as bellcranks, release if a jam is encountere
15、d in either the left or right control run that reaches a magnitude of 40 to 65 lb at the stick grip. provides incremental normal “g“ force feel at the stick in addition to the artificial feel provided by the spring/cam devices located by the actuator. Each A torque shaft cross connection between the
16、 two A bobweight and balance spring under the cockpit floor Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIRm4094 90 W 8357340 005L020 3 W AI R4094 3.1.2 (Continued): Redundant SAS signals are i
17、ntegrally summed with stick signals at each control surface actuator. The SAS signals are summed from two sources, pitch damping and speed brake cross feed and are dual redundant. to the left and right simplex elevator actuators are fully independent. When the two LVDTs differ beyond specified thres
18、holds, both SAS systems are automatically shut down. individually re-engaged at the pilots discretion. Signals Left and right SAS systems can be Roll control is effected by two ailerons each powered by tandem hydraulic servoactuators under the wings in faired armament pylons. Lateral stick signals a
19、re transmitted from the armored cockpit area via independent parallelogram cables separated into extreme left and right transmission paths at the aft end of the roll stick output pushrod (see Figure 4). Jam protection similar to that in pitch is afforded for both roll control systems. Fail operative
20、 capability with 5% roll rate control is retained subsequent to a jam. The aileron actuators are dual tandem units with the left and right hydraulic circuits fully independent. hydraulic power supply has no discernible effect on aileron response. Loss of both hydraulic power supplies automatically e
21、ngages the manual reversion mode in which pilot control is transferred to operate aileron servo tabs to move the ailerons for roll control. The roll axis is heavily damped and requires no stability augmentation system. Yaw control is effected through dual rudders with the cable run separating into l
22、eft and right linkages in the extreme aft fuselage to drive individual simplex rudder actuators (Figure 5). The yaw axis has dual stability augmentation systems similar to the pitch system. Electrical SAS signais to the actuator are summed from roll attitude, rudder trim, yaw rate gyro, and angle of
23、 attack times roll rate. These signals are added to the pedal commands to effect total command signals. As in the pitch SAS when two SAS LVDTs differ beyond a specified threshold, both SAS systems automatically shut down. indicated, a “4“ sensing switch limits rudder travel to t18“ to protect fins f
24、rom excessive air loads. Loss of one At aircraft speed above 240 knots -3- Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIR*11074 40 = 8357340 0051021 5 - AIR4094 -4- Copyright SAE International
25、 Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIR*90q 90 8357390 0053022 7 EIE - AIR4094 t- m I- .- t u L 6 LL I N W E 3 u H LI .- -5- Copyright SAE International Provided by IHS under license with SAENot for ResaleNo repr
26、oduction or networking permitted without license from IHS-,-SAE AIR*:4094 90 W 83573qO 0053023 9 - AIR4094 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIR*4094 90 M 8357340 0053024 O AIR4094 o
27、.- I O a Co o c c, .- U c cd 8 o O a L u -u t: 3 t -7- Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIRm4094 90 W 8357340 0053025 2 W AIR4094 -8- Copyright SAE International Provided by IHS unde
28、r license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIR*4094 90 W 8357340 005L02b 4 W Ele - AIR4094 3,2 Fairchild Republic T-46: The Fairchild Republic T-46 (Figure 6) is a two place twin engine jet trainer. Aircraft control is effected by two eleva
29、tors, two ailerons, and two rudders. The pitch and roll controls are fully manual while the rudder is serviced by a hydraulic actuator for yaw control. 3.2.1 System Description: roll and a type III for yaw which supports stability augmentation and a ful ly manual reversion capabi 1 i ty. The control
30、 runs have no mechani cal redundancy whi le the hydraulic rudder actuator has the capabi 1 i ty to retain 50% yaw control after any jam in the cable system or rudder surface downstream of the rudder actuator. The actuator can override cable force limiting springs in the cable system leading to the j
31、ammed side and transmit pilots command to the operable rudder surface. The flight control system is a type I for pitch and 3.2.2 System Mechanization: Control stick pitch motion is manually transmitted through a series of cable and pushrods (Figure 7) to two independently mounted elevators interconn
32、ected with a torque shaft. A spring balanced bobweight is incorporated to provide a stick force per G characteristic, the elevators are 70“L mass balanced and have aerodynamic balance. The elevators travel 32“ TEU and 10“ TED. A trim tab is mounted on the inboard edge of the right elevator. Roll con
33、trol is effected through spring tabs on the ailerons. A manual cable and pushrod system transmits control stick motion to aileron displacement (Figure 8). A pivoted conical mechanism generates 24“ TEU and 16“ TED aileron displacement for equal input cable travels. unequal aileron travels benefit pro
34、verse yaw. balanced while the aileron tabs are loo“/, mass balanced. The The ailerons are 70% mass The yaw control system is a type III, in which a single cable transmission path sends pedal commands to an irreversible hydraulic linear actuator (Figure 9). independent sets of control cables. Spring
35、force limiters limit rudder torques and travels to operational requirements regardless of full pedal deflections. provides a pedal force gradient peaking at 45 lb. The actuator positions two rudder surfaces through A springlcam centering device in the actuator assembly The yaw controls incorporate a
36、 SAS to augment dutch roll damping and minimize aircraft heading oscillations. Rate gyros sense rotational rates about yaw and output electrical signals to the actuator while a LVDT provides position feedback information to the hydraulic actuator. -9- Copyright SAE International Provided by IHS unde
37、r license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIR*4034 90 8357340 0053027 b SE AIR4094 c m I I- c V L - 10 - Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without licens
38、e from IHS-,-SAE AIR*q074 90 8357340 0053028 8 M bAC - AIR4094 C ris 03 .d v) Q O 5 Y o .- Yj 8 .; E U .r L U r O u c U c, n 3 P W .r c u - 11 - Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIR*
39、4074 90 8357340 0051029 T = * AIR4094 ar 30 00 cr aa .I .- -.I- .- .- el= Qo nr 30 O O .a 4 I- +I E I=+ *- w a O U c rd c U rn a, 7 O L c E O O 7 c O p: CD e I c LL - 12 - Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without
40、license from IHS-,-SAE AIR*4094 90 m 8357340 0051030 b m EAR! - AIR4094 O O w= +I I- V) n O i; I - 13 - Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-AIR4094 3.3 General Dynamics F-111: 3.3.1 F-111 F
41、light Control System Description: The primary flight control system provides control of the aircraft by movement of a rudder, a pair of spoilers on each wing and a pair of movable horizontal stabilizers. Pitch attitude of the aircraft is controlled by symmetrical deflection of the horizontal stabili
42、zer surfaces. Roll attitude is controlled by asymmetrical deflection of the horizontal stabilizer surfaces; and when the wing sweep angle is less than 45“, roll control is aided by action of two spoilers on top of each wing. deflection of a rudder surface located on the trailing edge of the vertical
43、 stabilizer. Hydraulic servoactuators are used to produce control surface movement. Yaw control is accomplished by A system of push-pull tubes, bellcranks, cables,.and pulleys are used to connect the cockpit controls with the rudder and horizontal stabilizer hydraulic actuators. The linkage connecti
44、ons are secured with self-retaining bolts, which use self-locking cotter keyed nuts. The stabi 1 i ty augmentation system employs redundant sensors, electronic circuitry and electrohydraulic dampers. The three damper actuators, the horizontal stabilizer actuators, and the rudder actuator are supplie
45、d by both primary and utility hydraulic systems and can operate on either system should one system fail. summarized below: 3.3.2 Pitch Channel (Figure 10): The salient features of the pitch channel are - Direct mechanical linkage from the control sticks to the left and right horizontal tai 1 actuato
46、rs - Parallel trim actuator for pilot trim - Series trim actuator provides the elevator required to trim (Auto Trim) - Pitch Damper System - Operates in.either the TAKEOFF (T.O.) and LAND mode or NORMAL mode, - Automatically provides the required gain by a self adaptive gain dependent upon the slat
47、position and the control system switch position changer system - Provides a nearly constant stick force per “g“ - Has electronic and hydraulic redundancy features Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license f
48、rom IHS-,-Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIRs4094 90 D 8357340 0053033 3 AIR4094 J - 16 - Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE AIR*4OSY 90 m 8357340 005103Y 3 m eAE iyT AIR4094 42 B Yog 1 I i r“ I I I ! I- I - 17 - Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without lice
