AD 77-11-02

final rule
Data completeness: 70%

Airworthiness Directives; Messerschmitt-Bolkow-Blohm GmbH Model BO-105 Helicopters

AD Number
77-11-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Airbus Helicopters Deutschland GmbH BO-105A Airworthiness Directives; Messerschmitt-Bolkow-Blohm GmbH Model BO-105 Helicopters
aircraft Airbus Helicopters Deutschland GmbH BO-105C Airworthiness Directives; Messerschmitt-Bolkow-Blohm GmbH Model BO-105 Helicopters
aircraft Airbus Helicopters Deutschland GmbH BO-105S Airworthiness Directives; Messerschmitt-Bolkow-Blohm GmbH Model BO-105 Helicopters

Unsafe Condition

Failure of the main rotor hub quadruple nuts and associated bolts could result in loss of the main rotor.

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

Required Actions

Inspect main rotor hub quadruple nuts (P/N 105-14101.19, 105-14101.20) and bolts (P/N 105-14101.22, 105-14101.23) with over 1,400 hours time in service using magnaflux or FAA-approved equivalent. Replace cracked parts before flight. Replace nuts/bolts before 2,400 hours total time in service.

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

Compliance Time

Within the next 100 hours time in service after the effective date (June 14, 1977), unless already accomplished within the last 200 hours time in service. Thereafter at intervals not to exceed 300 hours time in service from the last inspection.

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

Affected Aircraft

Messerschmitt-Bolkow-Blohm GmbH Model BO-105A, BO-105C, BO-105S helicopters certificated in all categories.

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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