WARNING CLACKER IS HEARD - Replace mach airspeed warning test switch and perform specified test (34-14-00).
NO WARNING CLACKER IS HEARD - Open MACH WARN circuit breaker on panel P12. Return test switch module to original configuration. Replace fuel tank airspeed warning switch and perform specified test (34-14-00).
T33553
EFFECTIVITY
AIRPLANES WITH SUPPLEMENTARY
726 Page 106 FUEL TANKS
34-14-00
Apr 25/79
MACH AIRSPEED WARNING SYSTEM - MAINTENANCE PRACTICES
____________________________________________________
1. Referenced Procedures
_____________________
A. 24-22-00, Maintenance Practices (Apply Power)
B. 34-11-00, Adjustment/Test
C. 34-14-00, Adjustment/Test (Operational Test)
2. Mach Airspeed Warning Gear Down Dispatch
________________________________________
A. General
(1)
When the airplane is dispatched to be flown with landing gear extended, placards are installed on captain's and first officer's mach airspeed indicator and the mach airspeed-gear down dispatch selector switch is placed in GEAR DOWN DISPATCH position. The gear down dispatch airspeed warning switch provides an aural warning if the airplane exceeds 270 knots.
(2)
The indicator placard stowage and MACH AIRSPEED-GEAR DOWN DISPATCH selector switch are located at the main equipment center E-2. (Fig. 201).
B. Gear Down Dispatch Procedure (Fig. 201)
(1) Set mach airspeed-gear down dispatch selector switch to GEAR DOWN
DISPATCH position. XA (2) Secure switch guard in open condition.
(3)
Remove indicator placards from placard stowage assembly.
(4)
Remove instrument memory index ring from captain's and first officer's mach airspeed indicator.
(5)
Position indicator placard and instrument memory index ring on mach airspeed indicators and fasten with screws.
3. Mach Airspeed/Gear Down Dispatch Airspeed/Fuel Tank Airspeed Warning
____________________________________________________________________ Switch - Removal/Installation
_____________________________
A. General
(1) Removal/Installation procedures for the airspeed warning switches are identical.
B. Remove Airspeed Warning Switch
(1)
Open MACH WARN circuit breaker on electrical circuit breaker panel P12.
(2)
In main equipment center, locate airspeed warning switch in lower half of mounting bracket on shelf E2-1 next to stanchion 3. Remove pitot and static system hoses from the front panel of warning switch.
(3)
Disconnect electrical cable from front panel of warning switch.
(4)
Remove screws from mounting flange on warning switch.
(5)
Slide warning switch assembly forward until it comes free of opening in mounting bracket.
C. Install Airspeed Warning Switch
(1)
In main equipment center, locate mounting hole in bracket on shelf E2-1 next to stanchion 3. Check four clip-in nuts for proper positioning.
(2)
Examine static and pitot pressure ports of warning switch being installed for male halves of quick-disconnect, pneumatic fittings threaded into ports. If fittings are not present, install them (with new O-rings).
EFFECTIVITY
ALL 21 Page 201 Dec 25/8734-14-00
SEE B
SEE A
MACH AIRSPEED -GEAR DOWN DISPATCH SELECTOR SWITCH
GEAR DOWN
DISPATCH
GEAR DOWN DISPATCH AIRSPEED MACH AIRSPEED WARNING SWITCH WARNING SWITCH
(REF) M192
NORMAL
SWITCH mo
V
GUARD
AIRSPEED
WARNING
PLACARD
SWITCH PANEL
STOWAGE
ASSEMBLY INSTRUMENT MEMORY
GEAR DOWN DISPATCH AIRSPEED
INDEX RINGINDICATOR
WARNING SWITCH, SELECTOR SWITCH,
PLACARD
AND PLACARD LOCATION
MACH AIRSPEED
INDICATOR
A
AIRSPEED INDICATOR PLACARD INSTALLATION B Mach Airspeed Warning System Componant Location Figure 201
EFFECTIVITY
ALL701 Page 202
34-14-00
Oct 10/73
(3)
With tested fittings in place and warning switch held in position, slide unit into mounting hole until mounting flange is flush with bracket.
(4)
Install screws and secure warning switch to mounting bracket.
(5)
Connect electrical cable to connector on front panel of warning switch.
(6)
Connect pitot and static system hoses from stanchion 3 to the two quick-disconnect fittings on front panel of warning switch. Use hose labeled "auxiliary pitot system No. 2" for input marked "P" (red fitting) and hose labeled "auxiliary static system No. 2" for input marked "S" (yellow fitting).
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航1(89)
