# AD 67-09-02: Main Rotor Mast

- Type: Airworthiness directive
- Status: Current
- Products: Brantly International B-2, B-2A and B-2B
- Effective: April 20, 1967
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-373
- Registered aircraft: 53 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B6A3D30BCBB8741C86256A380060B9B2.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/67-09-02

## The airworthiness directive

67-09-02 BRANTLY: Amdt. 39-373 Part 39 Federal Register March 21, 1967. Applies to Models B-2, B-2A, and B-2B Helicopters with P/N B2-324 Transmission Serial Numbers Prior to Serial Number 307.

Compliance required as indicated.

To improve the service life and reliability of the upper main rotor mast bearing, within the next 100 hours' time in service after the effective date of this AD, remove the Fafnir P/N 212K bearing presently installed and replace it with an Indiana Gear Works P/N 4524A56, Revision E, sealed bearing. This substitution is to be accomplished as prescribed by Brantly Helicopter Company Service Bulletin No. 21 and applicable sections of the Model B-2 Series helicopter maintenance manuals.

This directive effective April 20, 1967

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 2H2](https://openairdocs.org/tcds/2H2): Brantly International Inc.; names 3 of 3 models: B-2B, B-2A, B-2

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 53 (53 by airframe model, 0 by engine model)
- Makers: Brantly 53

Models with the most aircraft:

- [Brantly B-2B](https://openairdocs.org/model/brantly-b-2b): 34 aircraft (airframe model)
- [Brantly B-2](https://openairdocs.org/model/brantly-b-2): 17 aircraft (airframe model)
- [Brantly B-2A](https://openairdocs.org/model/brantly-b-2a): 2 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/67-09-02/models.md
Every aircraft: https://openairdocs.org/ad/67-09-02/aircraft.md

Its text cites no advisory circulars or STCs.

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