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Operations Manual Bulletin
for
International Lease Finance Corp.
The Boeing Company Seattle, Washington 98124-2207
Number: ILF2-49
Date: July 5, 2000 Document Effectivity: D6-30151-425 Subject: ENGINE BLEED AIR SHUTOFF ANOMALY Reason: To inform flight crews a system fault can result in the shutoff of all
engine bleed air.
Information in this bulletin is recommended by The Boeing Company, but may not be FAA approved at the time of writing. In the event of conflict with the FAA approved Airplane Flight Manual (AFM), the AFM shall supersede. The Boeing Company regards the information or procedures described herein as having a direct or indirect bearing on the safe operation of this model airplane.
THE FOLLOWING PROCEDURE AND/OR INFORMATION IS EFFECTIVE UPON RECEIPT
Background Information
An operator recently reported shutoff of bleed air from all engines during flight. Investigation revealed a single fault in the Air Supply Control Test Unit (ASCTU) can result in closure of all engine bleed air valves and illumination of all Engine Bleed Air OFF lights. In the reported incident the fault was intermittent. When the fault was removed, low-pressure bleed air became available and all Engine Bleed Air OFF lights extinguished. Cycling the Engine Bleed Air Switches recovered normal engine bleed air.
With this fault the BLEED 1, 2, 3 and 4 messages do not display. With bleed air shut off to all using systems, the following indications will be observed:
.
air conditioning packs shut down andPACK 1,PACK 2, andPACK 3
messages display (pressurization is gradually lost)
.
air driven hydraulic pumps (ADPs) will be unpowered and respective HYD
PRESS DEM messages display when ADPs are commanded to run
.
when flaps are selected, leading and trailing edge flaps operate in the
secondary mode (the FLAPS PRIMARY message displays)
.
wing and nacelle anti-ice systems are inoperative
.
thrust reversers are inoperative
.
The >TRIM AIR OFF message displays.
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Operations Manual Bulletin No. ILF2-49, Dated July 5, 2000 (continued)
Depending upon environmental conditions, cabin and flight deck temperatures can rise quickly. If necessary, remove as many sources of heat as possible by:
.
turning off all in-flight entertainment systems
.
turning off all galleys
.
closing all window shades to block sunlight. After descent to safe altitude, increase airflow throughout the airplane by:
. opening both outflow valves
. opening the smoke evacuation port
. if heat becomes excessive, opening a cabin door 1 and a cabin door 5. 中國航空網 www.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：747-441 Operations Manual 747操作手冊(31)
