AD 90-24-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | MD Helicopters, Inc. | 369D | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369D, 369E, and 369F/FF Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369E | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369D, 369E, and 369F/FF Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369F | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369D, 369E, and 369F/FF Series Helicopters |
| aircraft | MD Helicopters, Inc. | 369FF | Airworthiness Directives; MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369D, 369E, and 369F/FF Series Helicopters |
Unsafe Condition
Failure of the main rotor transmission drive assembly due to MS21250-04036 bolts with unacceptable head inscriptions or insufficient thread protrusion, which could result in loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect MS21250-04036 bolts retaining the debris cover (P/N 369D25174) for unacceptable head inscriptions per Figure 1 and replace with MS21250-04038 bolts. Inspect bolt thread protrusion through H14-4 nut; remove bolts not protruding two full threads (0.071 inch minimum), replace with MS21250-04038 bolts, torque to 50-70 inch-pounds, and add washers if more than four threads protrude. Apply a white dot to the main transmission data plate and record compliance in the rotorcraft log book.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 300 hours' time in service after the effective date of the AD or at the next annual inspection or the next time the transmission is removed, whichever occurs first.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC) Model 369D, 369E, and 369F/FF series helicopters 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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