AD Amdt-39-10989

Recurring final rule
Data completeness: 70%

Airworthiness Directives; McDonnell Douglas Helicopter Systems Model MD-900 Helicopters

AD Number
Amdt-39-10989
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 98-SW-24-AD
FR Citation
64 FR 2810

Applicability

TypeManufacturerModelDetails
aircraft McDonnell Douglas Helicopter Systems Model MD-900 Airworthiness Directives; McDonnell Douglas Helicopter Systems Model MD-900 Helicopters

Unsafe Condition

Cracks in the main rotor upper hub assembly could result in failure of the hub assembly, loss of drive to the main rotor, and subsequent loss of control of the helicopter.

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

Required Actions

Inspect the main rotor upper hub assembly for cracks. If a crack is found, replace the hub assembly. Verify attachment nut torque values. Implement a repetitive inspection at intervals not exceeding 150 hours time-in-service.

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

McDonnell Douglas Helicopter Systems Model MD-900 helicopters.

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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