曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
switch may need to be held for up to 20 seconds in order to remove the APU
ACCUM caution and provide a full charge (up to 40 seconds following an inflight
APU start).
NORM Allows normal aft isolation valve functioning.
If an APU ACCUM caution appears inflight and is not related to
emergency gear/probe extention or APU start, it may indicate a possible
leak in the isolated HYD 2B system. A BRK ACCUM caution inflight is
not normal and may indicate a possible leak in the isolated HYD 2B
system: In either case, do not select HYD ISOL ORIDE as this may result
in additional loss of HYD 2B fluid.
A1-F18EA-NFM-000
I-2-42 ORIGINAL
2.6.3 Hydraulic System Related Cautions and Caution Light. The following hydraulic system
related cautions and caution light are described in the Warning/Caution/Advisory Displays in Part V:
· HYD 1A, HYD 1B, HYD 2A, HYD 2B
· HYD 5000
· HYD 1 HOT, HYD 2 HOT
· BRK ACCUM
· APU ACCUM caution and caution light
2.7 UTILITY HYDRAULIC FUNCTIONS
The aircraft's utility hydraulic functions are powered by HYD 2 and include landing gear extension
and retraction, nosewheel steering, wheel braking and anti-skid, launch bar extension, arresting hook
retraction, and inflight refueling probe extension and retraction. Operation of the inflight refueling
probe is described in the Fuel System section.
2.7.1 Landing Gear System. The aircraft's landing gear is a tricycle design and includes a nose
landing gear with steerable nosewheel and two fixed main landing gear. The nose landing gear retracts
forward, while the main landing gear retract aft and inwards. When the landing gear is extended, all
landing gear doors remain open.
2.7.1.1 Planing Links. Each main landing gear assembly incorporates a planing link, which is
designed to properly align the main wheels after landing gear extension. The joint which connects the
wheel to the main landing gear lever is designed to rotate off-axis, so that the wheel fits properly into
the main landing gear wheelwell. The planing link rotates the main wheel from its stowed orientation,
aligns it with the longitudinal axis of the aircraft, and locks over-center. A planing link proximity
switch is used to verify proper planing link position and thereby proper wheel alignment. A flashing
main landing gear position light is used to provide an indication of a planing link failure.
2.7.1.2 Normal Landing Gear Extension and Retraction. Normal landing gear extension and
retraction is electrically controlled by the LDG GEAR handle and uses hydraulic pressure from HYD
2A. With weight off the nose gear and the launch bar retracted, moving the LDG GEAR handle to the
UP position sends an electrical signal to the landing gear selector valves to initiate normal landing gear
retraction. Likewise, moving the LDG GEAR handle to the DN position sends an electrical signal to the
landing gear selector valves to initiate normal landing gear extension
If the launch bar does not return to the up and locked position after catapult launch or the nose gear
indicates WonW, the nose landing gear cannot be retracted. In either case, placing the LDG GEAR
handle UP will raise the main landing gear and leave the nose landing gear extended.
2.7.1.3 Emergency Landing Gear Extension. Emergency landing gear extension is mechanically
controlled by the LDG GEAR handle (front cockpit) or the EMERG LDG GEAR handle (rear cockpit)
and uses hydraulic pressure provided by the APU accumulator. Both handles are mechanically
connected to the landing gear emergency selector valves by a series of levers and cables. Emergency
extension is mechanically activated by rotating the LDG GEAR handle 90° clockwise and pulling to
detent (approximately 1½ inches) or by pulling the EMERG LDG GEAR handle to the detent.
Emergency extension opens the hydraulic arming valve and directs APU accumulator pressure to the
emergency selector valves. APU accumulator pressure is used to unlock the doors and release the
landing gear uplocks. The nose landing gear extends by freefall aided by airloads, and the main landing
gear extends by freefall aided by the sidebrace downlock actuator. Emergency extension can be
performed with the LDG GEAR handle either UP or DN (DN is recommended).
A1-F18EA-NFM-000
I-2-43 ORIGINAL
2.7.1.4 LDG GEAR Handle. The wheel-shaped LDG GEAR handle, located on the lower left main
instrument panel in the front cockpit, is used to control landing gear extension and retraction. A
downlock solenoid in the LDG GEAR handle assembly prevents gear retraction with WonW by
preventing movement of the handle from the DN position.
UP With WoffW and the launch bar retracted, electrically initiates normal
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
NATOPS Flight Manual 飞行手册 1(50)
