# AD 63-04-02: Tail Rotor Blade

- Type: Airworthiness directive
- Status: Current
- Products: Hiller UH-12, UH-12A, UH-12B and UH-12C
- Effective: February 12, 1963
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Registered aircraft: 93 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/32F5911F2865F2C686256A38005F5D8C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/63-04-02

## The airworthiness directive

63-04-02 HILLER: Amdt. 535 Part 507 Federal Register February 12, 1963. Applies to All UH-12, UH-12A, UH-12B, and UH-12C Helicopters with P/N's 55008 and 55012 Tail Rotor Blades.

Compliance required as indicated.

To prevent failures of P/N's 55008 and 55012 tail rotor blades the following shall be accomplished:

  (a) Within the next 50 hours' time in service, unless already accomplished:

  (1) Replace all P/N's 55008 and 55012 tail rotor blades with P/N 55064 tail rotor blades in accordance with Hiller Service Bulletin No. 80.

  (2) On all helicopters equipped with the large diameter (1.375 inch) spar stabilizer, P/N 37003, install the stabilizer strut in accordance with Hiller Service Bulletin No. 75B.

  (3) On all helicopters equipped with the small diameter (1 inch) spar stabilizer, P/N 37001, install the stabilizer strut in accordance with Hiller Service Bulletin No. 83.

  (b) Until replacement with the P/N 55064 blade is accomplished, visually inspect the P/N's 55008 and 55012 tail rotor blades prior to each flight and refueling. The outer surface of the skin on both sides of the blade shall be inspected for cracks in the area of the outer tension torsion bar retention bolt and the adjacent rivet pattern through the outer end of the root fitting. Paint must be removed from the areas to facilitate inspection. Any blades found to be cracked must be removed and replaced with P/N 55064 blades prior to further flight.

(Hiller Service Bulletins Nos. 75B, 80, and 83 pertain to this subject.)

This supersedes AD 58-24-02. This directive effective February 12, 1963.

## Affected data sheets (2) (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

## 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: 93 (93 by airframe model, 0 by engine model)
- Makers: Hiller 84, Hiller - World Helicopters 2, Hiller-Felt 1, Hiller-Heli-Cab 1, Hiller-Helicopter Rep SVC 1, Hiller-Stanley 1, Hiller-Tri-Plex Ind.Inc. 1, Hiller-Trident Helicopters 1, Hiller-Yehnert 1

Models with the most aircraft:

- [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-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-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)

All 12 models: https://openairdocs.org/ad/63-04-02/models.md
Every aircraft: https://openairdocs.org/ad/63-04-02/aircraft.md

Its text cites no advisory circulars or STCs.

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