AD 77-21-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | MD Helicopters, Inc. | 369 | Airworthiness Directives; Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM and HS Helicopters |
| aircraft | MD Helicopters, Inc. | 369A | Airworthiness Directives; Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM and HS Helicopters |
| aircraft | MD Helicopters, Inc. | 369D | Airworthiness Directives; Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM and HS Helicopters |
| aircraft | MD Helicopters, Inc. | 369H | Airworthiness Directives; Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM and HS Helicopters |
| aircraft | MD Helicopters, Inc. | 369HE | Airworthiness Directives; Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM and HS Helicopters |
| aircraft | MD Helicopters, Inc. | 369HM | Airworthiness Directives; Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM and HS Helicopters |
| aircraft | MD Helicopters, Inc. | 369HS | Airworthiness Directives; Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM and HS Helicopters |
Unsafe Condition
Failure of the rotor drive overrunning clutch and shaft assembly can result in loss of power to the rotor main transmission.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Visually inspect the overrunning clutch assembly P/N 369A5350-11, drive shaft bearing P/N 369A5361, and bearing seal P/N 369A5368 for proper operation, lubrication, and condition per applicable Hughes Service Information Notices. Remove, inspect, and replace components as necessary, repack bearings with specified grease, and record compliance in the helicopter log book.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 10 hours time in service after receipt of this telegram, unless already accomplished in the last 25 hours time in service.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Hughes Model 369 (YOH-6A), 369A(OH-6A), D, H, HE, HM, and HS helicopters, certificated in all categories.
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
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.