- Effective
- February 9, 1981
- Models
- UH-12D, UH-12L, UH-12E
- Registered aircraft
- 128 matched by model
- Product
- Aircraft · Rotorcraft
- Amendment
- 39-4034
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
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On this page
The airworthiness directive
81-04-01 HILLER AIRCRAFT: Amendment 39-4034. Applies to Models UH-12D, UH-12E, OH-23G, UH-12L, and all models converted to turbine power in accordance with Supplementary Type Certificate STC 177WE or STC 178WE, certified in all categories.
Compliance required within ten (10) calendar days from the effective date of this AD, unless already accomplished.
To prevent rudder balance cables from fraying and breaking, accomplish the following:
(a) Perform a one time visual inspection of the rudder balance cable assembly, P/N HS 1053-2, in accordance with Hiller Service Bulletin No. 32-2 Part II, Accomplishment Instructions, Subparts A and B, dated December 31, 1980.
(b) Remove from service the rudder cable assemblies, P/N HS 1053-2, which do not conform to type design. Type design is 7 x 19 cable. The Hiller Service Bulletin No. 32-2 depicts the acceptable cable.
(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes or helicopters to a base for the accomplishment of inspections or modifications required by this AD.
(d) Alternative inspections, modifications or other actions which provide an equivalent level of safety may be used when approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region.
This amendment becomes effective February 9, 1981.
Affected TCDS · 3
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 128
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1957 | 4 |
|---|---|
| 1958 | 4 |
| 1959 | 7 |
| 1960 | 8 |
| 1961 | 6 |
| 1962 | 12 |
| 1963 | 2 |
| 1964 | 10 |
| 1965 | 6 |
| 1966 | 1 |
| 1973 | 1 |
| 1975 | 3 |
| 1976 | 7 |
| 1977 | 4 |
| 1978 | 3 |
| 1979 | 3 |
| 1980 | 3 |
| 1981 | 3 |
| 1982 | 3 |
| 1993 | 1 |
| 1996 | 1 |
36 with no year recorded