AD 97-05-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Schweizer Aircraft Corporation | 269A | Airworthiness Directives; Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, and TH-55A Helicopters |
| aircraft | Schweizer Aircraft Corporation | 269A-1 | Airworthiness Directives; Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, and TH-55A Helicopters |
| aircraft | Schweizer Aircraft Corporation | 269B | Airworthiness Directives; Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, and TH-55A Helicopters |
Unsafe Condition
Failure of the main rotor thrust bearing (bearing), loss of the main rotor, 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
Determine the time-in-service (TIS) of the bearing part numbers 269A5050-50, -51, or -73. Replace bearings with TIS equal to or exceeding 300 hours (for P/N -50/-51) or 3,000 hours (for P/N -73) before further flight. Inspect bearings for rotational roughness, corrosion, inadequate lubrication, physical damage, moisture, or zinc chromate paste buildup per SSN N-59. Inspect and modify thrust bearing nut and main rotor mast as required.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Required within 25 hours time-in-service (TIS) after the effective date of this AD, unless accomplished previously.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A (S/N 0011-1109), 269A-1 (S/N 0001-0041), 269B (S/N 0001-0444), and TH-55A helicopters with main rotor thrust bearing part numbers 269A5050-50, -51, or -73 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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