AD 98-10-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | CFM International, S.A. | CFM56-3 | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-3B | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-3C | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-5 | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-5B1 | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-5B1/2P | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-5B1/P | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-5B2 | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-5B2/2P | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-5B2/P | Airworthiness Directives; CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C Series Turbofan Engines |
Unsafe Condition
Failure of the accessory gearbox (AGB) starter gearshaft, transfer gearbox (TGB) input bevel gear, TGB output bevel gear, AGB gearshaft cluster spur assembly, or AGB intermediate gear assembly due to residual stresses from improper cleaning prior to the black oxide process during manufacture.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove one engine on twin-engine aircraft and replace with a serviceable engine or parts if both engines have affected components. Remove all affected engines on four-engine aircraft and replace with serviceable engines or parts. Perform daily checks of the AGB/TGB magnetic chip detector for engines listed in specified service bulletins. Install serviceable components within 30 days after the effective date or before further flight if abnormal magnetic particles are found.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within 30 days after the effective date of this AD or before further flight if abnormal magnetic particles are found
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C series turbofan engines with specific AGB starter gearshafts, TGB input/output bevel gears, AGB gearshaft cluster spur assemblies, or AGB intermediate gear assemblies installed, as listed in the referenced service bulletins.
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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