AD 78-11-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT3D-1 | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC6 | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC7 | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-1A | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-1A-MC6 | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-1A-MC7 | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-3 | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-3B | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-3C | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
| engine | Pratt & Whitney Division | JT3D-5A | PRATT & WHITNEY AIRCRAFT Model JT3D Engines |
Unsafe Condition
Failures of first stage fan blades due to forging laps, which could result in aircraft damage.
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Required Actions
Perform a one-time blue etch anodize inspection of the blades in accordance with Pratt & Whitney Alert Service Bulletin 4733 or later FAA approved revision, and Special Instruction 2F-77 or later FAA approved revision. Fan blades with blue etch linear indications in specified areas must be reworked or scrapped per Figure 2 of ASB 4733.
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Compliance Time
Not later than March 1, 1980, unless already accomplished.
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Affected Aircraft
Pratt & Whitney Aircraft JT3D turbofan engine models including JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-1A, JT3D-1A-MC6, JT3D-1A-MC7, JT3D-3, JT3D-3B, JT3D-3C, and others as listed.
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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