AD 99-11-12

final rule
Data completeness: 70%

Airworthiness Directives; Boeing Model 747-400 Series Airplanes

AD Number
99-11-12
Status
final_rule
Effective Date
Product Category
aircraft
Docket
97-NM-89-AD
FR Citation
(Federal Register: May 28, 1999 (Volume 64, Number 103))

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 747-400 Series Airworthiness Directives; Boeing Model 747-400 Series Airplanes
aircraft The Boeing Company 747-400D Series Airworthiness Directives; Boeing Model 747-400 Series Airplanes
aircraft The Boeing Company 747-400F Series Airworthiness Directives; Boeing Model 747-400 Series Airplanes

Unsafe Condition

Fatigue cracking of end cap bolts caused by improper installation and early fatigue cracking of properly installed end caps, which could lead to separation of the engine from the airplane in the event of a primary thrust linkage failure.

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

Required Actions

Conduct repetitive inspections to ensure proper installation of engine thrust link components and perform follow-on corrective actions if necessary. Replace the forward engine mount end cap assembly with an improved end cap assembly, which terminates the repetitive inspections upon completion.

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

Compliance Time

Before further flight

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

Affected Aircraft

Boeing Model 747-400 series airplanes, including 747-400D and 747-400F models, equipped with engine thrust link components requiring inspection and replacement.

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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