# AD 52-01-07: Engine Cooling Fan

- Type: Airworthiness directive
- Status: Current
- Products: Scotts-Bell 47 47D1
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Registered aircraft: 49 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1742241E277A908186256A34004EB651.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/52-01-07

## The airworthiness directive

52-01-07 BELL: Applies to All Model 47D1 Helicopters Having 47-661-030-1 Hub Assembly in the Cooling Fan. Refer to Bell Service Bulletin No. 72.

Compliance required at the next 300-hour overhaul, but not later than March 1, 1952.

To reduce the possibility of throwing blades in flight, rework the existing 47-661-030-1 hub and reassemble the fan using the parts provided in the modification kit. (Note: Do not install old fan blades.) Balance modified fan assembly (assigned P/N 47-661-036-5) in accordance with specified erection and maintenance procedure prior to installation.

(Bell Service Bulletin No. 82 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: 47D1

## 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: 49 (49 by airframe model, 0 by engine model)
- Makers: Bell 47, 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 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 3 models: https://openairdocs.org/ad/52-01-07/models.md
Every aircraft: https://openairdocs.org/ad/52-01-07/aircraft.md

Its text cites no advisory circulars or STCs.

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