AD 2021-15-52

final rule
Data completeness: 80%

Airworthiness Directives; Various Restricted Category Helicopters

AD Number
2021-15-52
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2021-0605
FR Citation
86 FR 40779

Applicability

TypeManufacturerModelDetails
aircraft Textron Inc Airworthiness Directives; Various Restricted Category Helicopters
aircraft Bell Textron Inc Airworthiness Directives; Various Restricted Category Helicopters

Unsafe Condition

A pin part number (P/N) 204-012-104-005 with a serial number (S/N) prefix 'FNFS' sheared off during flight, resulting in the main rotor blade and the main rotor head detaching from the helicopter.

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

Required Actions

Remove pins P/N 204-012-104-005 with an S/N prefix 'FNFS' before further flight. Prohibit installing those pins on any helicopter as of the effective date of this AD.

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

Restricted category helicopters originally manufactured by Bell Textron Inc., including but not limited to, Rotorcraft Development Corporation Model HH-1K helicopters, Robinson Air Crane Inc.; Rotorcraft Development Corporation; and Tamarack Helicopters, Inc., Model TH-1F helicopters, and others.

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

Source: Official FAA Source ↗

Retrieved: Apr 4, 2026

Rights: U.S. Government Public Domain

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