27-32-42
COMPUTER P/N 65-52822 ú ú 02 Page 405 ú Nov 15/98
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A
737-300/400/500MAINTENANCE MANUAL
HORIZONTAL STABILIZER TRIM CONTROL SYSTEM -
___________________________________________ DESCRIPTION AND OPERATION
_________________________
1. General (Fig. 1 and 2)_______
A. The horizontal stabilizer trim control system provides longitudinal trim of the airplane by varying the angle of attack of the horizontal stabilizer. The horizontal stabilizer is moved through 17 degrees of travel by means of a jackscrew with ball nut. The primary stabilizer trim actuator and a cable drum on the jackscrew gearbox provide for trim control from three separate control systems. The normal control is an electrical system which actuates the jackscrew through the primary stabilizer trim actuator. Autopilot control is provided by the PSTA. A manual control system drives through cables to the cable drum on the jackscrew gearbox. The manual system remains engaged at all times and is therefore back-driven by the PSTA during normal operation. Manual system operation will disengage the PSTA if this system becomes jammed. A continuous indication of stabilizer position is provided by trim position indicators adjacent to trim wheels on the control stand. The indicators are positioned by the manual system. A takeoff warning system indicates any unsafe stabilizer position for takeoff (AMM 31-26-00/001). The control column actuated cutout switch located under the cockpit floor, stops electric trimming of the stabilizer when opposed by the motion of the elevator control.
Horizontal Stabilizer Trim Control System Component Location
Figure 1 (Sheet 1)
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27-41-00
ALL ú ú 03 Page 1 ú Jul 12/01
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A 737-300/400/500MAINTENANCE MANUAL
STABILIZER TRIM CONTROL SWITCH CONTROL COLUMN
COLUMN ACTUATED
CUTOUT SWITCH
OVERRIDE
STABILIZER TRIMSTABILIZER CONTROL SWITCH TRIM WHEEL
STABILIZER POSITION INDICATOR
ELEVATOR TORQUE TUBE
IDLER
SPROCKET
CRANK COLUMN ACTUATED CUTOUT SWITCH
CHAIN ASSEMBLY
INDICATOR FLEXIBLE SHAFT AFT SUPPORT LINK
STB CABLE 1
STA CABLE 1
FORWARD
FORWARD CABLE DRUM
SUPPORT
LINK
FORWARD TRIM
MECHANISM
SPROCKET
FORWARD TRIM 1 APPROXIMATLEY 4-1/2 WRAPS
MECHANISM OF STB CABLE FROM TOP OF
TURNBUCKLE GEAR HOUSING DRUM AND 28-1/2 WRAPS OF
STA CABLE FROM BOTTOM OF
DRUM WITH STABILIZER
POSITIONED AT FULL AIRPLANE
NOSEDOWN
POSITION INDICATOR AND MANUAL CONTROL MECHANISM
A
Horizontal Stabilizer Trim Control System Component Location
Figure 1 (Sheet 2)
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A
737-300/400/500
MAINTENANCE MANUAL
SAFETY ROD
JACKSCREW
BALLNUT
STABILIZER
PRIMARY STRUCTURE
STABILIZER
TRIM ACTUATOR
GREASE FITTING
UPPER GIMBAL
LOWER STOP
GEARBOX (UPPER STOP
NOT SHOWN BUT
EQUIVALENT)
UMBRELLA
ASSEMBLY
PLATE COVER
STA CABLE STB CABLE GIMBAL LOWER
FWD CABLE DRUM GEARBOX
B STABILIZER ACTUATOR MECHANISM
Horizontal Stabilizer Trim Control System - Component Location
Figure 1 (Sheet 3)
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27-41-00
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本文链接地址：737-300 400 500 AMM 飞机维护手册 飞行操纵 FLIGHT CONTROLS 3(68)
