79-18-13: Third Stage Turbine Wheel
FAA order 79-18-13 is an airworthiness directive in force since September 6, 1979. The FAA's subject line: Third Stage Turbine Wheel. It names the Rolls-Royce 250-C28B, Rolls-Royce 250-C47 series engines: about 19 aircraft on the U.S. register today across them, 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
- Engine
- Makes
- Rolls-Royce Corporation
- Models
- 250-C28B, 250-C28C
- Engine series
- Rolls-Royce 250-C28B 3 aircraft
Rolls-Royce 250-C47 series 16 aircraft
Dates and paperwork
- In force since
- September 6, 1979
- 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 (936 characters)
79-18-13 DETROIT DIESEL ALLISON: Amendment 39-3548. Applies to all Model 250-C28B and 250-C28C Series engines equipped with third stage turbine wheel P/Ns 6898553 or 6898773 installed in, but not limited to Bell 206L-1 rotorcraft certificated in all categories.
Compliance required as indicated unless previously accomplished.
A. For turbine wheels with less than 300 hours total time in service, compliance is required before reaching 325 hours total time in service.
B. For turbine wheels with more than 300 hours total time in service, compliance is required within 25 hours time in service.
To preclude engine power loss due to possible turbine blade failure, remove above listed third stage turbine wheels from service.
This amendment becomes effective September 6, 1979, as to all persons except those to whom it was made immediately effective by the airmail letter dated July 19, 1979, which contained this amendment.
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 October 30, 2026. Connections as data: /graph/directive/79-18-13.json · aircraft systems.