# AD 51-26-01: Tail Rotor Reinforcement

- Type: Airworthiness directive
- Status: Current
- Products: Scotts-Bell 47 47B, 47B3, 47D and 47D1
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Registered aircraft: 54 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D665767F3F402C5186256A34004E7921.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/51-26-01

## The airworthiness directive

51-26-01 BELL: Applies to All Models 47B, 47B3, 47D, 47D1 Helicopters.

A. Compliance required by October 15, 1951, unless Bell Service Instruction 67S1 has been accomplished already.

To provide additional strength to preclude the possibility of tail rotor failures, wrap each tail rotor blade across the junction of the stainless steel leading edge at the root end area of each blade with two strips of unidirectional fiberglass cloth, Bell P/N 47-642-020-14.

(Bell Service Bulletin No. 75 covers this same subject.)

B. Compliance required daily.

Inspect the tail rotor stainless steel leading edge for evidence of loosening or lifting. Carefully inspect the 3/32 radius, the flanges of leading edge at forward edge of reinforcement plates, and the entire root area for cracks. Replace blades immediately if any of these conditions exist.

(Bell Service Bulletin No. 75, revised October 11, 1951, covers this same subject.)

This supersedes AD 51-23-01.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H-1](https://openairdocs.org/tcds/H-1): Scott's-Bell 47 Inc; names 4 of 9 models: 47B, 47B3, 47D1, 47D

## 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: 54 (54 by airframe model, 0 by engine model)
- Makers: Bell 52, Bell Kitz Kopters 1, Bell-Allied Helicopter 1

Models with the most aircraft:

- [Bell 47D1](https://openairdocs.org/model/bell-47d1): 47 aircraft (airframe model)
- [Bell 47D](https://openairdocs.org/model/bell-47d): 4 aircraft (airframe model)
- [Bell 47B](https://openairdocs.org/model/bell-47b): 1 aircraft (airframe model)
- [Bell Kitz Kopters 47D1](https://openairdocs.org/model/bell-kitz-kopters-47d1): 1 aircraft (airframe model)
- [Bell-Allied Helicopter 47D1](https://openairdocs.org/model/bell-allied-helicopter-47d1): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/51-26-01/models.md
Every aircraft: https://openairdocs.org/ad/51-26-01/aircraft.md

Its text cites no advisory circulars or STCs.

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