AD 86-17-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Rolls-Royce Corporation | 501-D13 | ALLISON GAS TURBINE DIVISION, GENERAL MOTORS CORP. (Allison, formerly Detroit Diesel Allison) Models 501-D13, -D13A, -D13D, and -D13H Engines |
| engine | Rolls-Royce Corporation | 501-D13A | ALLISON GAS TURBINE DIVISION, GENERAL MOTORS CORP. (Allison, formerly Detroit Diesel Allison) Models 501-D13, -D13A, -D13D, and -D13H Engines |
| engine | Rolls-Royce Corporation | 501-D13D | ALLISON GAS TURBINE DIVISION, GENERAL MOTORS CORP. (Allison, formerly Detroit Diesel Allison) Models 501-D13, -D13A, -D13D, and -D13H Engines |
| engine | Rolls-Royce Corporation | 501-D13H | ALLISON GAS TURBINE DIVISION, GENERAL MOTORS CORP. (Allison, formerly Detroit Diesel Allison) Models 501-D13, -D13A, -D13D, and -D13H Engines |
Unsafe Condition
The possibility of unwanted autofeather or inability to autofeather when required due to thrust sensitive switch assemblies with part numbers 6792891, 6794122, 6794359, 6807776, 23005483, or 23005485.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace thrust sensitive switch assemblies with part number 6870559 in accordance with Allison Commercial Engine Alert Bulletin CEB-A-73-84, Revision 2, or FAA approved equivalent.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within 60 days after the effective date of this AD
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Allison 501-D13, -D13A, -D13D, and -D13H engine reduction gear assemblies equipped with thrust sensitive switch assemblies P/N 6792891, 6794122, 6794359, 6807776, 23005483, or 23005485.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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