H28733
Mach Trim Flap Switch Installation 500
22-21-31 Figure 401 Aug 15/68
Page 402
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
MACH TRIM FLAP SWITCH - ADJUSTMENT/TEST
1. Flap Mach Trim Switch Adjustment
A. Prepare Flap Mach Trim Switch for Adjustment
(1)
Connect electrical power and energize load control center P6.
(2)
Position flap control lever to FLAP DOWN detent.
NOTE: Flap control lever is moved to FLAP DOWN position as a standard procedure to minimize load on flap hydraulic motor when hydraulic system A is pressurized.
(3)
On circuit breaker panel P6-2:
(a)
Close TE ALT FLAP DRIVE MOTOR circuit breaker.
(b)
Close FLAP VALVES circuit breaker.
B. Adjust Flap Mach Trim Switch
(1)
Position alternate flap switch too ARM. Verify that trailing edge flaps are extended 1 degree or more. If flaps are fully retracted, actuate alternate flap switch to DOWN, and hold until flaps are extended to 1 degree position.
(2)
Actuate alternate flap switch to UP and hold. When flap drive stops at full up position, release flap switch. Verify that No. 4 ball screw nut is 1-3/4 to 2-1/4 turns from up stop on ball screw yoke (Fig. 501). If this dimension is not obtained, adjust flap up limit switch per 27-51-291 prior to adjusting flap mach trim switch.
NOTE: Do not disconnect torque tubes to position flaps.
(3)
Remove switch cover from flap control unit (Fig. 502).
(4)
Measure and record dimension X (Fig. 501)). Actuate alternate flap switch to DOWN for several revolutions of jackscrew. Actuate alternate flap switch to UP, release switch to stop flaps at dimension X plus 0.10士0.05 inches. This dimension must be obtained by moving flaps in the up direction.
500
May 01/75 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 22-21-31 Page 501
H28735 H28737
Flap Jackscrew Stops 500
22-21-31 Figure 501 May 15/68
Page 502
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
500 Mach Trim Flap Switch Installation
Aug 15/68 Figure 502 22-21-31
Page 503
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
(5)
Adjust retaining nuts on flap mach trim switch to position switch body as close as possible toward actuating cam, then adjust retaining nuts to move switch away from actuating cam until switch actuates (audible click).
NOTE: Care must be taken to preposition switch so that actuation occurs when switch body is moved away from cam.
(6)
Tighten retaining nuts.
(7)
Lockwire switch retaining nuts.
(8)
Replace switch cover on flap control unit.
2. Mach Trim Flap Switch Test
A. Prepare Mach Trim Flap Switch for Test
(1)
Check that control surfaces are free to travel and flaps are in full up position
(2)
Provide power to airplane and energize busses on load control center P6.
(3)
Close mach trim circuit breakers on load control center P6 (or P18 on airplanes with SP177 autopilot system).
(4)
Pressurize hydraulic system A and B (Ref 29-11-0 MP and 29-12-0 MP).
WARNING: MAKE SURE ALL PERSONNEL AND OBSTRUCTIONS ARE CLEAR OF AILERON, ELEVATOR, OUTBOARD SPOILERS AND RUDDER SYSTEMS. SURFACES AND CONTROLS MAY MOVE ABRUPTLY WHEN HYDRAULIC POWER IS APPLIED.
B. Test Mach Trim Flap Switch (Airplanes with SP-77 autopilot system or SP-177 AFCS)
(1)
Press mach trim cockpit test switch and hold. Observe mach trim warning light is illuminated.
(2)
Lower flaps to 1 unit. Observe mach trim warning light extinguishes.
(3)
Raise flaps. Observe mach trim warning light illuminates.
(4)
Release mach trim cockpit test switch.
505
22-21-31 Page 504 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Oct 20/93
C. Test Mach Trim Flap Switch (Airplanes with SP-177 AFCS)
(1)
Verify that AFCS circuit breakers are closed and system is operational (Ref 22-11-01 A/T).
(2)
Verify that FLT CONT SYS circuit breakers are closed and position flight control hydraulic system A and B switches to ON.
WARNING: MAKE SURE ALL PERSONNEL AND OBSTRUCTIONS ARE CLEAR OF ELEVATOR, AILERON, RUDDER AND TAB SURFACES. SURFACES MAY MOVE ABRUPTLY WHEN HYDRAULIC POWER IS APPLIED. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737 AMM 飞机维护手册 AUTO FLIGHT 自动飞行 2(79)
