AD 83-03-02 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Rolls-Royce Corporation | 250-B17 | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
| engine | Rolls-Royce Corporation | 250-B17B | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
| engine | Rolls-Royce Corporation | 250-B17C | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
| engine | Rolls-Royce Corporation | 250-B17D | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
| engine | Rolls-Royce Corporation | 250-C20 | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
| engine | Rolls-Royce Corporation | 250-C20B | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
| engine | Rolls-Royce Corporation | 250-C20C (T63-A-720) | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
| engine | Rolls-Royce Corporation | 250-C20F | ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines |
Unsafe Condition
Partial blade and/or shroud separation of slotted third stage turbine wheels could cause possible engine power loss.
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Required Actions
Replace affected turbine wheels within specified time frames based on wheel time since new (TSN). Implement placards, markings, or flight manual changes to restrict engine operation between 90-98% N2 (except transients) and maintain ground idle N1/N2 speeds as specified.
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Compliance Time
Compliance required within the next 100, 400, 600, or 850 hours time in service, or prior to exceeding TSN thresholds, whichever comes first; or by August 12, 1983, for operational restrictions.
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Affected Aircraft
Allison Model 250-B17, -B17B, -B17C, -B17D, -C20, -C20B, -C20C (T63-A-720), and -C20F engines with specific slotted third stage turbine wheels (part numbers listed in the source).
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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