FLAP LANDING WARNING SWITCH - ADJUSTMENT/TEST
1. General
A. Before adjusting flap landing warning switch, the flap system must be rigged (Ref Chapter 27, Trailing Edge Flap System).
B. Flap up limit switch is part of the flight control system and is adjusted and tested as part of that system (Ref Chapter 27, Limit Switches).
2. Flap Landing Warning Switch Adjustment (Fig. 501)
A. Adjust Flap Landing Warning Switch
(1)
Connect external electrical power.
(2)
Retract flaps with flap control lever to normal retracted position (zero-unit detent) and hold for 5 minutes.
(3)
Remove No. 4 jackscrew fairing and record dimension between upstop of ball screw nut and upstop on screw yoke.
(4)
Move flap control lever to the 10-unit detent and , if necessary, position flaps electrically so that dimension X is an additional 23.17 to 23.32 inches from that recorded in step (3) (Ref 27-51-0, Adjustment/Test).
(5)
Remove cover from flap control unit.
(6)
Adjust flap landing warning switch away from actuating cam until switch actuates.
NOTE: There will be an audible click as switch actuates.
(7)
Tighten inner checknut on switch and lockwire.
(8)
Install cover on flap control unit.
(9)
Test switch per par. 3.
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Flap Landing Warning Switch Adjustment 501
31-26-12 Figure 501 Feb 20/90
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BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
3. Flap Landing Warning Switch Test
A. Equipment and Materials
(1) Gear Ground Lockpins - F72735
B. Prepare for Test
(1)
Jack airplane until wheels clear ground (Ref Chapter 7, Jacking Airplane).
(2)
Simulated landing gear position may be utilized when airplane jacks are not available, or jacking airplane is not possible.
(3)
Check that external power supply is connected.
(4)
Check that all landing gear and landing gear warning system circuit breakers on circuit breaker panel P6 are closed.
(5)
Check that all gear ground lockpins are installed.
(6)
Pressurize hydraulic system A (Ref 29-11-0 MP).
C. Test Flap Landing Warning Switch
(1)
Advance both engine thrust levers to a position greater than 25 degrees above idle stop.
(2)
Remove right main gear ground lockpins. Operate override trigger and retract right main landing gear.
(3)
If landing gear position is to be simulated, simulate right main gear retracted as described below. Also simulate air mode.
(a)
Place landing gear lever in off position. Check that all red gear lights come on and green lights remain on. Warning horn remains silent.
(b)
Place a copper deactuator shield between right main gear downlock sensor s73 and steel actuator arm.
(c)
Place a steel actuator bar over right main gear uplock sensor switch s74 located beside the right main gear uplock hook.
(d)
To simulate air mode for the main landing gear, disconnect the push-pull teleflex cable from the right main gear upper torsion link. Simulate air mode by extending the cable. Reconnect cable when complete. Do not in any way overstress the cable.
CAUTION: GENTLY PULL THE TELEFLEX CABLE UNTIL THE AIR/GND SENSOR ACTIVATES. IF THE CABLE IS NOT PULLED WITH CARE THE SENSOR TARGET BRACKET CAN BE BENT AND DAMAGED.
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(4)
Extend trailing edge flaps and check that warning horn sounds at greater than 10 units (between 10 and 15 units) of flap extension and continues to sound at al1 greater flap angles.
(5)
Press horn reset button and check that horn continues to sound.
(6)
Fully retract flaps and check that horn cuts out between 10 and 15 units of flap extension and is silent at 10 units and all lesser flap angles (units).
D. Restore Airplane to Normal Configuration
(1)
Extend right main landing gear and install gear ground lockpin.
(2)
If gear position was simulated, simulate a gear extension by removing all copper deactuator shields and steel actuator bars. Return the teleflex cable to its original position.
(a) Red lights should extinguish and green lights will illuminate. 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 通讯描述和操作(71)
