AD 2021-19-17
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky | Aircraft Corporation | Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters |
Unsafe Condition
A manufacturing defect in the main back tube assembly of certain Martin-Baker side facing utility and observer seats installed on Sikorsky Model S-92A helicopters, which can cause excessive lumbar loads during a crash event.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the main back tube assembly in affected side facing utility and observer seats, and prohibit installing those seats unless the main back tube assembly has been replaced.
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Compliance Time
Before further flight
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Affected Aircraft
Sikorsky Model S-92A helicopters with certain Martin-Baker side facing utility or observer seats installed, including seats with main back tube assembly part number MBCS4109 and/or seat part numbers MBCS12410AA001, MBCS12200, MBCS7301-2, and other part numbers as identified by Martin-Baker.
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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