AD 78-14-08

final rule
Data completeness: 70%

DETROIT DIESEL ALLISON Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20, and 250-C20B Engines

AD Number
78-14-08
Status
final_rule
Effective Date
Product Category
engine
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
engine Rolls-Royce Corporation 250-C18 DETROIT DIESEL ALLISON Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20, and 250-C20B Engines
engine Rolls-Royce Corporation 250-C18A DETROIT DIESEL ALLISON Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20, and 250-C20B Engines
engine Rolls-Royce Corporation 250-C18B DETROIT DIESEL ALLISON Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20, and 250-C20B Engines
engine Rolls-Royce Corporation 250-C18C DETROIT DIESEL ALLISON Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20, and 250-C20B Engines
engine Rolls-Royce Corporation 250-C20 DETROIT DIESEL ALLISON Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20, and 250-C20B Engines
engine Rolls-Royce Corporation 250-C20B DETROIT DIESEL ALLISON Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20, and 250-C20B Engines

Unsafe Condition

Fuel pump drive spline failure could cause engine flameout.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect fuel pump drive splines according to specified service letters. Replace worn parts or modify pump per engine bulletins if spline wear exceeds criteria. Modify all affected fuel pumps per bulletins before specified times.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Compliance required within 25 hours time in service and again each 200 hours time in service thereafter for pumps with 200+ hours on AD effective date; prior to reaching 225 hours time in service and every 200 hours thereafter for those with less than 200 hours. Modification required prior to 1500 hours time in service for pumps with <1475 hours, within 25 hours for those >1475, and for overhauled pumps.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Rolls-Royce Corporation engines: Model 250-C18/250-C18A/250-C18B/250-C18C/250-C20/250-C20B equipped with fuel pump P/Ns 6854292, 6856250, 6857548, 6876803, and 6877719.

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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