47-41-04: Main Rotor Mast Plug
FAA order 47-41-04 is an airworthiness directive. The FAA's subject line: Main Rotor Mast Plug. 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: rotorcraft systems.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Scotts-Bell 47 Inc
- Models
- 47B, 47B3
- 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 (478 characters)
47-41-04 BELL: (Was Mandatory Note 16 of AD-1H-2.) Applies to Models 47B and 47B3 Helicopters.
Compliance required not later than next 50-hour transmission teardown inspection after December 1, 1947.
To improve attachment of the inner race bearing on the bottom of the main rotor mast and to prevent possible chipping, the lower mast plug should incorporate a bolted retaining washer.
(Bell Service Bulletin 47C41 dated June 26, 1947, covers the detail installation.)
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/47-41-04.json · aircraft systems.