# AD 55-25-01: Bellcrank Attachment Bolt

- Type: Airworthiness directive
- Status: Current
- Products: Scotts-Bell 47 47G
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Registered aircraft: 60 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D3C6DCEE5AD3025186256A34004F3441.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/55-25-01

## The airworthiness directive

55-25-01 BELL: Applies to Model 47G Helicopters Below Serial Number 1450 Which Have Hydraulic Boost System Installed.

Compliance required as soon as practical but not later than January 15, 1956.

The manufacturer advises that the lateral cyclic bellcrank, P/N 47-725-073-1 attachment bolt P/N AN 174-34 is too short, positioning the threaded area in the forward lateral bellcrank support bracket hole, which may result in the threads flattening out and elongating the support bracket bolt hole.

It is therefore requested that the bolt holes in the bellcrank support bracket be inspected for elongation and the bolt replaced with a longer bolt. If the bolt holes are found elongated beyond permissible tolerance (maximum hole diameter of 0.2520 inch) doubler plates must be added. Redrill and line ream new holes. Replace the AN 174-34 bolt with a new longer bolt P/N AN 174-35, unless doubler plates are added, in which case install AN 174-36 bolts.

(Bell's Mandatory Service Bulletin No. 104, dated November 11, 1955, covers this same subject.)

## 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 1 of 9 models: 47G

## 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: 60 (60 by airframe model, 0 by engine model)
- Makers: Bell 55, Bell-K-Copter 2, Bell-Carson 1, Bell-Shippey 1, Continental Copters 1

Models with the most aircraft:

- [Bell 47G](https://openairdocs.org/model/bell-47g): 55 aircraft (airframe model)
- [Bell-K-Copter 47G](https://openairdocs.org/model/bell-k-copter-47g): 2 aircraft (airframe model)
- [Bell-Shippey BELL 47G](https://openairdocs.org/model/bell-shippey-bell-47g): 1 aircraft (airframe model)
- [Bell-Carson 47G](https://openairdocs.org/model/bell-carson-47g): 1 aircraft (airframe model)
- [Continental Copters 47G](https://openairdocs.org/model/continental-copters-47g): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/55-25-01/models.md
Every aircraft: https://openairdocs.org/ad/55-25-01/aircraft.md

Its text cites no advisory circulars or STCs.

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