52-28-03: Tail Rotor Gearbox Shaft
FAA order 52-28-03 is an airworthiness directive. The FAA's subject line: Tail Rotor Gearbox Shaft. 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
- 47, 47B, 47B3, 47D, 47D1, 47E, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, 47K
- 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 (342 characters)
52-28-03 BELL: Applies to All 47 Series Helicopters With the 47-645-002 Gearbox Installed.
Compliance required as directed.
Replace the tail rotor gearbox shaft, P/N 47-645-077-1, when it has accumulated 900 hours of operation.
(Bell's Mandatory Service Bulletin No. 83, Revision A, dated October 2, 1952, 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/52-28-03.json · aircraft systems.