AD 94-09-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Honeywell International Inc. | TPE331-1 | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-2 | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-2UA | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-3U | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-3UW | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-5 | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-5A | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-6 | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TPE331-6A | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
| engine | Honeywell International Inc. | TSE331-3U | ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION Model TPE331-1, -2, -2UA, -3U, -3UW, -5, - 5A, -6, and -6A and TSE331-3U Engines |
Unsafe Condition
Third stage turbine stator assemblies assembled with inner seal supports made of incorrect material (Hastelloy S) result in significantly reduced cyclic life and potential fatigue failure, leading to uncontained failure of the third stage turbine wheel.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect third stage turbine stator assemblies (P/N 868379-3) repaired at GGASD Phoenix between Nov 1988 and May 1991, and replace with serviceable assemblies per ASB TPE331-A72-0906. Compliance schedules vary by cycles in service since repair: within 50 cycles for ≥900 cycles, within 150 cycles (not exceeding 950 total) for 450-899 cycles, and prior to 600 cycles for <450 cycles. Use cycles calculated as hours ×1.5 if cycles unknown.
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Compliance Time
Within specified cycles in service after the effective date of this AD (May 20, 1994), based on cycles since repair by GGASD: 50 cycles for ≥900, 150 cycles (not exceeding 950) for 450-899, and prior to 600 cycles for <450.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Allied-Signal Inc., Garrett Engine Division TPE331-1, -2, -2UA, -3U, -3UW, -5, -5A, -6, -6A turboprop and TSE331-3U turboshaft engines with third stage stator turbine assemblies (P/N 868379-3) repaired at GGASD Phoenix between November 1988 and May 1991, as listed in ASB TPE331-A72-0906.
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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