# AD 69-21-01: Failure of Input Pinion Shaft

- Type: Airworthiness directive
- Status: Current
- Products: Schweizer 269A, 269A-1, 269B, 369H, 369HE, 369HM and 369HS
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-859
- Registered aircraft: 213 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/223CEF3B36F78E1386256A38006BC941.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/69-21-01

## The airworthiness directive

69-21-01 HUGHES: Amdt. 39-859. Applies to Model 269 and 369H series helicopters with Hughes P/N 269A6027 or 369A5400 tail rotor transmission installed.

Compliance required prior to further flight unless already accomplished.

To prevent loss of tail rotor power due to possible failure of the input pinion shaft (a part of the 369A5425 gear shaft assembly) of certain tail rotor transmissions accomplish the following:

Prior to further flight, determine if the serial number of the transmission gearbox installed is one of those listed in Hughes Service Information Notice, No. N-71, dated September 24, 1969 or later FAA approved revisions (all 269 series), or Hughes Service Information Notice No. HN-1, dated September 24, 1969, or later FAA approved revisions (all Model 369H series). If the gearbox is listed, and if the total time in service of the gearbox is in excess of 90 hours, replace the gearbox before the next flight with a gearbox marked with "M" on the tail rotortransmission identification plate or a serial number not listed in the Hughes Notices. For those gearboxes listed with less than 90 hours total time in service, replace the gearbox before 90 hours total time in service. If the tail rotor gearboxes are in spares inventory and within the listed serial numbers, they must not be installed on any aircraft.

NOTE: The tail rotor transmission identification plate will be stamped with the letter "M" following the serial number to indicate installation of a satisfactory input pinoin shaft.

Hughes Service Information Notice N-71 dated September 24, 1969, or later FAA approved revisions and HN-1 dated September 24, 1969 or later FAA approved revisions cover same subject.

This amendment becomes effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated September 26, 1969.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H3WE](https://openairdocs.org/tcds/H3WE): MD Helicopters LLC; names 4 of 12 models: 369HS, 369HM, 369HE, 369H
- [TCDS 4H12](https://openairdocs.org/tcds/4H12): Schweizer RSG LLC; names 3 of 6 models: 269B, 269A-1, 269A

## 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: 213 (213 by airframe model, 0 by engine model)
- Makers: Hughes 206, MD Helicopters 5, Schweizer 1, Summa 1

Models with the most aircraft:

- [Hughes 269A](https://openairdocs.org/model/hughes-269a): 97 aircraft (airframe model)
- [Hughes 369HS](https://openairdocs.org/model/hughes-369hs): 69 aircraft (airframe model)
- [Hughes 269B](https://openairdocs.org/model/hughes-269b): 31 aircraft (airframe model)
- [Hughes 269A-1](https://openairdocs.org/model/hughes-269a-1): 5 aircraft (airframe model)
- [MD Helicopters 369HS](https://openairdocs.org/model/md-helicopters-369hs): 3 aircraft (airframe model)
- [Hughes 369HE](https://openairdocs.org/model/hughes-369he): 3 aircraft (airframe model)
- [MD Helicopters 369HM](https://openairdocs.org/model/md-helicopters-369hm): 2 aircraft (airframe model)
- [Summa 369HS](https://openairdocs.org/model/summa-369hs): 1 aircraft (airframe model)
- [Hughes 369H](https://openairdocs.org/model/hughes-369h): 1 aircraft (airframe model)
- [Schweizer 269A](https://openairdocs.org/model/schweizer-269a): 1 aircraft (airframe model)

All 10 models: https://openairdocs.org/ad/69-21-01/models.md
Every aircraft: https://openairdocs.org/ad/69-21-01/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.