32-00-03
 ALL  ú ú 02 Page 603 ú Jul 12/00 
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details. 
A 
737-300/400/500MAINTENANCE MANUAL
 LANDING GEAR SAFETY SENSORS - DESCRIPTION AND OPERATION
_______________________________________________________
 1.  General_______
 A. Main Landing Gear Safety Sensors
 (1)  
The main landing gear safety sensors (Fig. 1) provide signals to solid state circuits in the landing gear electrical module to energize or de-energize the safety relays depending upon whether the airplane is airborne or on the ground. The sensors are mounted near the ground spoiler (lockout) valve above the right main gear. The sensors are proximity switches that sense the presence or the absence of a metal actuator. A double-paddle metal actuator is connected to the spoiler valve linkage to actuate the sensors. The spoiler valve linkage is operated by extension and compression of the shock strut through a teleflex cable. Linkage movement positions the actuator for the respective sensor to provide the appropriate signal.
 B. 
Nose Landing Gear Safety Sensor
 (1)  
A nose gear air sensing proximity sensor is located on the steering collar of the nose gear shock strut (Fig. 2). The sensor is a proximity switch operated by an actuator mounted on the upper torsion link. When the airplane leaves the ground, the shock strut extends, pivoting the upper torsion link toward the shock strut. This moves the actuator in front of the sensor and causes the sensor to conduct.
 (2)  
The NOSE sensing light ( LED ) uses the nose air sensing proximity sensor for input. The light ( LED ) is on in the air mode and is located on the E11 logic shelf. The light is labeled NOSE and has the note at the top that the light is " on in air ".
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
 32-09-00
 ALL  ú ú 01 Page 1 ú Nov 15/95 
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details. 
A 737-300/400/500MAINTENANCE MANUAL 
CABLE TELEFLEX LANDING GEAR RIGHT MAIN  
FWD  SAFETY SENSORS LANDING GEAR  
SEE  A  GROUND SPOILER INTERLOCK VALVE  
SENSOR AIR SAFETY 
TELEFLEX  
ACTUATOR  CABLE  
GROUND SAFETY SENSOR 
GROUND SPOILER  
INTERLOCK VALVE  
FWD  OUTBD  
A  
Main Landing Gear Safety Sensors  
Figure 1 
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址:737-300 400 500 AMM 飞机维护手册 起落架 LANDING GEAR 1(12)