52-01-07: Engine Cooling Fan
FAA order 52-01-07 is an airworthiness directive. The FAA's subject line: Engine Cooling Fan. It names Bell 47: about 478 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Scotts-Bell 47 Inc
- Models
- 47D1
- On this site
- Bell 47 478 registered
Dates and paperwork
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (650 characters)
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.)
Related safety bulletins advice on the same designs, not orders
2001-02-09SW-01-13 ·
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/52-01-07.json · aircraft systems.