AD 99-23-21

final rule
Data completeness: 70%

Airworthiness Directives; BOEING Model 757 Series Airplanes

AD Number
99-23-21
Status
final_rule
Effective Date
Product Category
aircraft
Docket
99-NM-101-AD
FR Citation
(Federal Register: November 16, 1999 )

Applicability

TypeManufacturerModelDetails
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

Operation with an energized sync lock or malfunctioning sleeve locking devices could result in deployment of a thrust reverser in flight and subsequent reduced controllability of the airplane.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Replace the reverse thrust switches and actuators with improved switches and actuators, modify the reverse lever links and thrust control levers, and replace the spring bumper assemblies of the thrust reverser sleeve with improved assemblies in accordance with specified service bulletins.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 2 years after the effective date of the AD

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Boeing Model 757 series airplanes listed in Boeing Service Bulletins 757-76-0009 (Rev 1) or 757-78-0012, including 757-200, 757-200CB, 757-200PF, and 757-300 series models.

AI-generated summary from the source AD text. Verify against the official source before acting.

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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