AD 94-12-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Schweizer Aircraft Corporation | 269A | Airworthiness Directives; Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A Series Helicopters |
| aircraft | Schweizer Aircraft Corporation | 269A-1 | Airworthiness Directives; Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A Series Helicopters |
| aircraft | Schweizer Aircraft Corporation | 269B | Airworthiness Directives; Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A Series Helicopters |
| aircraft | Schweizer Aircraft Corporation | 269C | Airworthiness Directives; Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A Series Helicopters |
Unsafe Condition
Failure of the lower belt drive pulley bearings, leading to loss of power to the rotor systems and subsequent loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace pulley bearings with specific part numbers if they have accumulated 1,750 or more hours' time-in-service. Inspect pulley bearings in accordance with specified service information notices (SIN N-146.2 and SIN N-164) at intervals not exceeding 300 hours' time-in-service. Shim bearing straps and address out-of-roundness issues as per the service information.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 50 hours' time-in-service after the effective date of this AD, and thereafter at intervals not to exceed 300 hours' time-in-service from the last inspection.
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Affected Aircraft
Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters with lower belt drive pulley bearings, part number 269A5050-57 or 269A5050-80, installed.
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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