AD 98-14-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | CFM International, S.A. | CFM56-7B20 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B20/2 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B22 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B22/2 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B24 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B24/2 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B26 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B26/2 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B26/B1 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
| engine | CFM International, S.A. | CFM56-7B27 | Airworthiness Directives; CFM International CFM56-7B Series Turbofan Engines |
Unsafe Condition
Uncontained failures of the Accessory Gearbox (AGB) starter gearshafts due to inadequate fatigue capability caused by high residual tensile stresses from manufacturing processes and elimination of shotpeening in the gearshaft hub.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Check the Accessory Gearbox/Transfer Gearbox Magnetic Chip Detector (AGB/TGB MCD) for abnormal magnetic particles on the No. 2 engine first, followed by the No. 1 engine every other calendar day. Remove and replace suspect starter gearshafts (part number 340-055-202-0) identified in CFMI SB 72-130 Table 1 with serviceable parts. Report discrepancies to the FAA within 5 working days.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Prior to further flight for initial checks. For replacement: within 350 hours time in service (TIS) after the effective date or by August 1, 1998, whichever comes first for aircraft with two affected engines; within 725 hours TIS or by September 1, 1998, for aircraft with one affected engine.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
CFM International CFM56-7B series turbofan engines (models CFM56-7B20, CFM56-7B22, CFM56-7B24, CFM56-7B26, etc.) with starter gearshafts part number 340-055-202-0, as listed in CFMI SB 72-130 Table 1.
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
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.