AD 2000-10-12
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 747-400 | Airworthiness Directives; Boeing Model 747-400 Series Airplanes |
Unsafe Condition
Cracking and buckling of the front edge of the crew rest heat exchanger, which could result in jamming of the rudder or elevator control cables and reduced controllability of the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Perform a general visual inspection of the crew rest heat exchanger to detect deflection or damage, in accordance with Boeing Alert Service Bulletin 747-21A2412. Repeat the inspection at intervals not to exceed 2,500 flight hours. If damage or deflection is found, replace the affected heat exchanger and measure the thickness of the material. If the thickness is within specified limits, return the discrepant heat exchanger to Boeing.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 1,200 flight hours or 90 days after the effective date of this AD, whichever occurs first.
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Affected Aircraft
Boeing Model 747-400 series airplanes, line numbers 1 through 1205 inclusive, certificated in any category, and equipped with dual crown skin heat exchangers.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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