(2)
If either of the nose air/ground sensors fail in the air mode while on the ground, then the message NOSE A/G SYS will show on the EICAS status/maintenance display.
C.
Main Gear Truck Tilt Sensors (Fig. 1)
____________________________
(1)
Two proximity sensors (S10062, LH, S10060 RH) for system 1, and two proximity sensors (S10064 LH, S10059 RH) for system 2, are located on the outboard side of the truck beam, aft of the main gear shock strut. The sensors provide air/ground signal to the PSEU. The PSEU converts the signal for energizing or de-energizing the relays. One of the on ground signals from system 1 and sytem 2 also goes to the left and right EICAS computers for air/ground output comparison. If the on ground signal outputs from systems 1 and 2 do not agree, the computers provide an AIR/GND DISAGREE message on the EICAS status/maintenance display.
(2)
If either the system 1 or system 2 air/ground logic fails in the air mode while on the ground, then the message AIR/GND SYS will show on the EICAS status/maintenance display.
3. Operation (Fig. 3)_________
A. Functional Description
(1)
Power
(a)
AIRPLANE WITH ETOPS; Refer to the data that follows: 1) All air/ground relays, except one, receive 28v dc power
from their respective landing gear AIR/GND SYS 1, POS SYS 1, AIR/GND SYS 2, POS SYS 2 or LANDING GEAR POS SYS 2 ALTN circuit breakers on overhead circuit breaker panel P11.
2) One air/ground relay receives its 28v dc power from the HYD GEN CONT circuit breaker on main power distribution panel P6.
32-09-02
ALL ú ú 08 Page 4 ú Sep 28/01
ENERGIZED IN AIR
L/R EICAS CMPTRPRESSURIZED WHENEVER LEFT HYDRAULICSYSTEM POWER IS SUPPLIED AND LANDINGGEAR CONTROL LEVER IS NOT IN OFF POSITION
ONLY APPLICABLE TO THE
LANDING GEAR POS SYS 2
Air/Ground Relays SchematicFigure 3 (Sheet 1)
A
757
MAINTENANCE MANUAL
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH -17 PSEU ú
32-09-02
ú ú 04 Page 5 ú Jan 28/02
ENERGIZED IN AIR
L/R EICAS CMPTRPRESSURIZED WHENEVER LEFT HYDRAULICSYSTEM POWER IS SUPPLIED AND LANDINGGEAR CONTROL LEVER IS NOT IN OFF POSITION
ONLY APPLICABLE TO THE
LANDING GEAR POS SYS 2
Air/Ground Relays SchematicFigure 3 (Sheet 2)
A
757
MAINTENANCE MANUAL
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH -24 PSEU ú
32-09-02
ú ú 01 Page 6 ú Jan 28/02
A
757
MAINTENANCE MANUAL
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. GUN 006-999 WITH THE -24 PSEU ú
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本文链接地址：757 AMM 飞机维护手册 起落架 CHAPTER 32 - LANDING GEAR 1(27)
