# AD 71-23-01: Safety of Aileron Cable Turnbuckles

- Type: Airworthiness directive
- Status: Current
- Products: Pilatus PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2 and PC-6/C-H2
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-1326
- Registered aircraft: 3 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/43B59D587A9E0E2886256A45006EE6C7.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/71-23-01

## The airworthiness directive

71-23-01 PILATUS AIRCRAFT: Amdt. 39-1326. Applies to Pilatus Model PC-6 (Heli-Porter) airplanes manufactured by Fairchild Hiller.

Compliance is required as indicated.

  (a) Before further flight, unless already accomplished, inspect the aileron control cable turnbuckles for safety wires that meet the size and corrosion resistance specifications and the method of safetying specifications of Military Standard 20995C47 and Military Standard 33591, respectively, or FAA-approved equivalents.

  (b) Within the next 50 hours' time in service after the effective date of this AD or before November 15, 1971, whichever occurs sooner, inspect the rudder, elevator, and flap control cables turnbuckles for safety wires that meet the size and corrosion resistance specifications of Military Standard 20995C47 and Military Standard 33591, respectively, or FAA-approved equivalent.

  (c) If turnbuckle safety wires are found that do not meet the size or corrosion resistance specificationsor the method of safetying specifications of Military Standard 20995C47 and Military Standard 33591, respectively, or FAA-approved equivalents, during an inspection required by paragraph (a) or (b), before further flight, except that the airplane may be flown in accordance with FAR 21.197 to a base where the repairs can be performed, replace affected turnbuckle safety wires with safety wires that meet those specifications or FAA-approved equivalents.

  (d) Within the next 50 hours' time in service after the effective date of this AD or before November 15, 1971, whichever occurs sooner, inspect the rudder and elevator trim cable turnbuckles for safety wires that meet the size and corrosion resistance specifications and the method of safetying specifications of Military Standard 20995C32 and Military Standard 33591, respectively, or FAA-approved equivalents.

  (e) If turnbuckle safety wires are found that do not meet the size or corrosion resistance specifications or the method ofsafetying specifications of Military Standard 20995C32 and Military Standard 33591, respectively, or FAA-approved equivalents, during an inspection required by paragraph (d), before further flight, except that the airplane may be flown in accordance with FAR 21.197 to a base where the repairs can be performed, replace affected turnbuckle safety wires with safety wires that meet those specifications or FAA-approved equivalents.

(Fairchild Hiller Service Letter PC-6-27-2, dated July 20, 1971, refers to this subject).

This amendment is effective upon publication in the Federal Register as to all persons except those persons to whom it was made effective immediately upon receipt of the airmail letter dated October 9, 1971, which contained this amendment.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 7A15](https://openairdocs.org/tcds/7A15): Pilatus Aircraft Ltd.; names 12 of 15 models: PC-6/350-H1, PC-6/B-H2, PC-6/A-H2, PC-6/C-H2, PC-6, PC-6/A-H1, PC-6-H2, PC-6-H1…

## 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: 3 (3 by airframe model, 0 by engine model)
- Makers: Pilatus 3

Models with the most aircraft:

- [Pilatus PC-6/B1-H2](https://openairdocs.org/model/pilatus-pc-6-b1-h2): 2 aircraft (airframe model)
- [Pilatus PC-6](https://openairdocs.org/model/pilatus-pc-6): 1 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/71-23-01/models.md
Every aircraft: https://openairdocs.org/ad/71-23-01/aircraft.md

Its text cites no advisory circulars or STCs.

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