AD 77-15-01

final rule
Data completeness: 70%

Airworthiness Directives; Messerschmitt-Bolkow-Blohm (MBB) Model BO-105A and BO-105C Helicopters

AD Number
77-15-01
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 (MBB) Model BO-105A and BO-105C Helicopters
aircraft Airbus Helicopters Deutschland GmbH BO-105C Airworthiness Directives; Messerschmitt-Bolkow-Blohm (MBB) Model BO-105A and BO-105C Helicopters

Unsafe Condition

Failure of the tail-rotor drive system due to cracks in the tail boom skin in the vicinity of the three bearing brackets, P/N 105-30251.17, .18, and .19.

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

Required Actions

Within 5 hours time in service after the effective date, inspect tail boom skin for cracks near the specified bearing brackets. Repeat inspections every 50 hours if no cracks found; if cracks found, stop-drill cracks under 10 mm and inspect every 10 hours, or perform service bulletin if more severe cracks. Compliance with service bulletin required before further flight if conditions met.

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

Compliance Time

within the next 5 hours time in service after the effective date of this AD

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

Affected Aircraft

Messerschmitt-Bolkow-Blohm (MBB) Model BO-105A and BO-105C Helicopters, except those with tail-rotor shaft bearing bracket P/N 105-30251.40.

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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