# AD 59-05-05: Cyclic Control Scissor Casting - Type: Airworthiness directive - Status: Current - Products: Hiller UH-12, UH-12A, UH-12B, UH-12C, UH-12D and UH-12E - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Registered aircraft: 221 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F19B006709EA7CB386256A38005F41A8.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/59-05-05 ## The airworthiness directive 59-05-05 HILLER: Applies As Follows: (a) UH-12, UH-12A, and UH-12B Incorporating Hiller Service Bulletin Numbers 50 or 50A After July 1, 1957. (b) UH-12C, Serial Numbers 934 and Up. (c) UH-12D, All Serial Numbers. (d) All Spare P/N 34141 Castings Delivered By Hiller After July 1, 1957. All UH-12 Series and All Serial Numbers Incorporating These Spares Are Affected. Compliance required as indicated. Due to improper casting techniques, two cyclic control scissor castings, P/N 34141, have failed in service on Model H-23D helicopters. As there is a possibility that additional P/N 34141 castings are defective, the following measure are required to detect cracks and prevent further failures: (1) Prior to every flight and refueling, visually inspect P/N 34141 casting for cracks if part has accumulated more than 275 hours. If cracks are detected, the part must be removed from service prior to further flight. (2) Effective September 1, 1959, P/N 34141 casting (including basic number and all dash numbers) must be removed from service prior to accumulation of 275 hours total time. (3) Upon replacement with a new forging P/N 34158, the special inspection of item (1) may be discontinued. This forging has unlimited service life. ## Affected data sheets (4) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS 6H1](https://openairdocs.org/tcds/6H1): Siam Hiller Holdings Inc.; names 2 of 2 models: UH-12, UH-12A - [TCDS 6H2](https://openairdocs.org/tcds/6H2): Siam Hiller Holdings Inc.; names 2 of 2 models: UH-12C, UH-12B - [TCDS 4H10](https://openairdocs.org/tcds/4H10): Siam Hiller Holdings Inc.; names 1 of 1 models: UH-12D - [TCDS 4H11](https://openairdocs.org/tcds/4H11): Siam Hiller Holdings Inc.; names 1 of 2 models: UH-12E ## 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: 221 (221 by airframe model, 0 by engine model) - Makers: Hiller 209, Hiller - World Helicopters 2, Hiller-Osborn 2, Hiller-Felt 1, Hiller-Heli-Cab 1, Hiller-Helicopter Rep SVC 1, Hiller-Rogerson Helicopter 1, Hiller-Stanley 1, Hiller-Tri-Plex Ind.Inc. 1, Hiller-Trident Helicopters 1 Models with the most aircraft: - [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e): 103 aircraft (airframe model) - [Hiller UH-12B](https://openairdocs.org/model/hiller-uh-12b): 35 aircraft (airframe model) - [Hiller UH-12C](https://openairdocs.org/model/hiller-uh-12c): 31 aircraft (airframe model) - [Hiller UH-12D](https://openairdocs.org/model/hiller-uh-12d): 22 aircraft (airframe model) - [Hiller UH-12A](https://openairdocs.org/model/hiller-uh-12a): 16 aircraft (airframe model) - [Hiller UH-12](https://openairdocs.org/model/hiller-uh-12): 2 aircraft (airframe model) - [Hiller - World Helicopters UH-12C](https://openairdocs.org/model/hiller-world-helicopters-uh-12c): 2 aircraft (airframe model) - [Hiller-Osborn UH-12D](https://openairdocs.org/model/hiller-osborn-uh-12d): 2 aircraft (airframe model) - [Hiller-Yehnert UH-12](https://openairdocs.org/model/hiller-yehnert-uh-12): 1 aircraft (airframe model) - [Hiller-Stanley UH-12C](https://openairdocs.org/model/hiller-stanley-uh-12c): 1 aircraft (airframe model) - [Hiller-Felt UH-12C](https://openairdocs.org/model/hiller-felt-uh-12c): 1 aircraft (airframe model) - [Hiller-Helicopter Rep SVC UH-12B](https://openairdocs.org/model/hiller-helicopter-rep-svc-uh-12b): 1 aircraft (airframe model) - [Hiller-Tri-Plex Ind.Inc. UH-12B](https://openairdocs.org/model/hiller-tri-plex-ind-inc-uh-12b): 1 aircraft (airframe model) - [Hiller-Trident Helicopters UH-12C](https://openairdocs.org/model/hiller-trident-helicopters-uh-12c): 1 aircraft (airframe model) - [Hiller-Heli-Cab UH-12B](https://openairdocs.org/model/hiller-heli-cab-uh-12b): 1 aircraft (airframe model) - [Hiller-Rogerson Helicopter UH12E](https://openairdocs.org/model/hiller-rogerson-helicopter-uh12e): 1 aircraft (airframe model) All 17 models: https://openairdocs.org/ad/59-05-05/models.md Every aircraft: https://openairdocs.org/ad/59-05-05/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.