AD 66-21-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT3C-12 | PRATT & WHITNEY Model JT3C-7 and JT3C-12 Engines |
| engine | Pratt & Whitney Division | JT3C-7 | PRATT & WHITNEY Model JT3C-7 and JT3C-12 Engines |
Unsafe Condition
The first, fifth, and sixth stage compressor rotor disc spacer assemblies (P/N 359410, 359414, and 359415) may fail due to insufficient strength, leading to engine failure.
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Required Actions
Replace the first, fifth, and sixth stage compressor rotor disc spacer assemblies with new spacer assemblies P/N 460599, 460604, and 460606 respectively. Compliance must be completed within the next 6,000 hours' time in service after the effective date or at the next compressor disassembly, whichever occurs first.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 6,000 hours' time in service after the effective date of this AD or at the next compressor disassembly, whichever occurs first
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Affected Aircraft
Pratt & Whitney Model JT3C-7 and JT3C-12 engines
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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