AD 81-26-01 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | MD Helicopters, Inc. | 369 | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369A | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369D | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369E | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369F | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369FF | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369H | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369HE | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369HM | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369HS | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369 Series Helicopters |
Unsafe Condition
Failure of the main rotor drive shaft, part number 369D25510, which could result in the loss of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Visually inspect the spherical spline and adjacent shaft area of the drive shaft per specified service information notices. Replace cracked parts with serviceable parts before return to service and continue inspections at 300-hour intervals. Establish drive shaft retirement at 3,410 hours for Models 369F and FF, and 5,020 hours for Models 369D and E.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Prior to the accumulation of 300 hours' total time in service on the P/N 369D25510 drive shaft, or within the next 25 hours' additional time in service from December 17, 1981, for the Model 369D or from the effective date of this amended AD for Models 369E and F (whichever occurs later), and thereafter at repetitive intervals not to exceed 300 hours' additional time in service since the last such inspection.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All Model 369 series helicopters equipped with main rotor drive shaft, part number 369D25510, certificated in any category.
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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