AD Amdt-39-10233

final rule
Data completeness: 70%

Airworthiness Directives; Allison Engine Company Model 250-C40B Turboshaft Engines

AD Number
Amdt-39-10233
Status
final_rule
Effective Date
Product Category
engine
Docket
Docket No. 97-ANE-31-AD
FR Citation
62 FR 64517

Applicability

TypeManufacturerModelDetails
engine Allison Engine Company Model 250-C40B Airworthiness Directives; Allison Engine Company Model 250-C40B Turboshaft Engines

Unsafe Condition

Manufacturing defect in certain helical power takeoff gearshaft assemblies, which could result in fatigue failure and subsequent loss of engine power and inflight engine shutdown.

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

Required Actions

Install a placard requiring pilots to record torque level and time in service operating above 86% engine torque until defective parts are replaced. Replace defective parts no later than December 31, 2000, or earlier if maintenance actions are accomplished or operational restrictions are exceeded.

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

Compliance Time

Before further flight if maintenance actions are accomplished or operational restrictions are exceeded, otherwise no later than December 31, 2000.

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

Affected Aircraft

Allison Engine Company Model 250-C40B turboshaft engines with helical power takeoff gearshaft assemblies identified by specific serial numbers.

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

Source: Official FAA Source ↗

Retrieved: Apr 6, 2026

Rights: U.S. Government Public Domain

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