# AD 77-05-02: Main Rotor Blades

- Type: Airworthiness directive
- Status: Current
- Products: Bell Helicopter Textron 212
- Effective: March 10, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-2846
- Registered aircraft: 59 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8504ED4B13BB0C3D86256A340054DF5C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/77-05-02

## The airworthiness directive

77-05-02 BELL: Amendment 39-2846. Applies to Bell Model 212 helicopters certificated in all categories.

Compliance required as indicated.

To prevent possible failure of certain main rotor blades having possible corrosion or fretting in the blade weight bolt holes or other defects in the spar, accomplish the following for main rotor blades, P/N 204-012-001-23 and -29.

For blades with less than 1475 hours' total time in service on the effective date of this AD, remove these blades from further service prior to attaining 1500 hours' total blade time in service.

For blades with 1475 or more hours' total blade time in service on the effective date of this AD, remove these blades from further service within 25 hours' time in service.

This AD does not apply to blades, P/N 204-012-001-33.

(Bell Helicopter Textron message dated February 17, 1977, to all Model 212 operators pertains to this subject.)

This amendment becomes effective March 10, 1977.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H4SW](https://openairdocs.org/tcds/H4SW): Bell Textron Inc.; names 1 of 4 models: 212

## 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: 59 (59 by airframe model, 0 by engine model)
- Makers: Bell 54, Bell Helicopter Textron 5

Models with the most aircraft:

- [Bell 212](https://openairdocs.org/model/bell-212): 54 aircraft (airframe model)
- [Bell Helicopter Textron 212](https://openairdocs.org/model/bell-helicopter-textron-212): 5 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/77-05-02/models.md
Every aircraft: https://openairdocs.org/ad/77-05-02/aircraft.md

Its text cites no advisory circulars or STCs.

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