AD 90-22-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 757-200 Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
| aircraft | The Boeing Company | 757-200CB Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
| aircraft | The Boeing Company | 757-200PF Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
| aircraft | The Boeing Company | 757-300 Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
Unsafe Condition
Engine flameout due to boost pump bypass valve freezing.
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Required Actions
Perform an operational test of the fuel boost pump bypass valves within 150 flight hours after May 4, 1988, and every 300 flight hours thereafter. Modify the valves within 4,000 hours time-in-service after November 21, 1990.
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Compliance Time
Prior to the accumulation of 150 flight hours after May 4, 1988, and thereafter at intervals not to exceed 300 flight hours. Within the next 4,000 hours time-in-service after the effective date of this amendment.
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Affected Aircraft
BOEING Model 757-200 Series, 757-200CB Series, 757-200PF Series, 757-300 Series airplanes listed in Boeing Alert Service Bulletin 757-28A0017, Revision 2 or 3.
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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