# AD 72-16-09: Tail rotor input gear shaft assys

- Type: Airworthiness directive
- Status: Current
- Products: MD Helicopters 369A and 369H
- Effective: August 8, 1972
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-1497
- Registered aircraft: 47 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6E9EA987B910E71C86256A390048EDC7.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/72-16-09

## The airworthiness directive

72-16-09 HUGHES: Amendment 39-1497. Applies to Hughes Model 369A and 369H Series Helicopters certificated in all categories.

Compliance required as indicated.

To prevent possible failure of the input gearshaft assembly, accomplish the following:

  (a) For those helicopters incorporating tail rotor input gearshaft assemblies (see NOTE for P/N's) which have accumulated 2,000 hours' or more time in service on the effective date of this AD, accomplish (c) and (d), below, unless already accomplished, prior to further flight.

  (b) For those helicopters incorporating tail rotor input gearshaft assemblies (see NOTE for P/N's) which have accumulated 1,800 hours' or more time in service on the effective date of this AD, accomplish (c) and (d), below, within 100 additional time in service, unless already accomplished. If the additional time in service would result in a total time in service in excess of 2000 hours, the 100 hours' compliance time shall be reduced by that amount necessary to prevent any tail rotor input gearshaft assemblies from being operated beyond 2000 hours before accomplishment of this AD.

  (c) Revise the helicopter logbook, as applicable, to record both the input and the output gearshaft assemblies incorporated in the 369A5406 tail rotor gear set, per the instructions of Part I of Hughes Service Information Notice No. HN-53, dated July 24, 1972, or later FAA approved revisions.

  (d) Retire and replace the 369A5425 and 369A5425-3 input gearshaft assemblies (input part of 369A5406 gearset), per the instructions of Part II of Hughes Service Information Notice No. HN-53, dated July 24, 1972, or later FAA approved revisions. Owners and operators may exercise the options specified in Part II of the Notice.

NOTE: The part number assemblies and finite life are:

TAIL ROTOR INPUT FINITE GEARSHAFT ASSEMBLY LIFE P/N 369A5406 (input only) 1,800 hours P/N 369A5425, -3 1,800 hours P/N 369A5425-5 27,600 hoursNOTE: The P/N 369A5406 tail rotor gearset is comprised of an input gearshaft assembly and a pinion output gearshaft assembly. The finite life of all existing pinion output gearshaft assemblies remains unchanged at 2,940 hours.

This amendment becomes effective August 8, 1972.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H3WE](https://openairdocs.org/tcds/H3WE): MD Helicopters LLC; names 2 of 12 models: 369H, 369A (Army OH-6A)

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 47 (47 by airframe model, 0 by engine model)
- Makers: Hughes 44, Hughes/Batto John 1, Hughes/Helicopter Assocs 1, MD Helicopters 1

Models with the most aircraft:

- [Hughes 369A](https://openairdocs.org/model/hughes-369a): 32 aircraft (airframe model)
- [Hughes 369A (OH-6A)](https://openairdocs.org/model/hughes-369a-oh-6a): 11 aircraft (airframe model)
- [MD Helicopters 369A](https://openairdocs.org/model/md-helicopters-369a): 1 aircraft (airframe model)
- [Hughes/Helicopter Assocs 369A](https://openairdocs.org/model/hughes-helicopter-assocs-369a): 1 aircraft (airframe model)
- [Hughes/Batto John 369A (OH-6A)](https://openairdocs.org/model/hughes-batto-john-369a-oh-6a): 1 aircraft (airframe model)
- [Hughes 369H](https://openairdocs.org/model/hughes-369h): 1 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/72-16-09/models.md
Every aircraft: https://openairdocs.org/ad/72-16-09/aircraft.md

Its text cites no advisory circulars or STCs.

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