AD 82-13-04 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12L | Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12L4 | Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12E | Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12E-L | Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters |
Unsafe Condition
Possible loss of driving torque to the helicopter rotor system due to torsional couplings P/N 21047-9 and -11 serial numbers 497 through 766.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect torsional couplings P/N 21047-9 and -11 per Hiller Aviation Service Bulletin UH-12-21-1, revise inspection schedule if serviceable, replace if non-compliant, and use special flight permits as allowed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 50 hours' time in service after September 13, 1982, or within 300 hours' time in service since September 8, 1980, whichever occurs earlier, and thereafter every 300 hours' time in service.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Hiller Aviation/Siam Hiller Holdings, Inc. Models UH-12E, UH-12E-L, UH-12L, UH-12L4 equipped with torsional couplings P/N 21047-9/-11 serial numbers 497-766, excluding turbine-converted models under STC SH178WE/SH177WE unless restored to original configuration.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Torsional Couplings
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_82-13-04_R.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 82-13-04 R1 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters Subject: Torsional Couplings Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 09/13/1982 Make: Hiller Aviation | Siam Hiller Holdings, Inc. Model: UH-12L | UH-12L4 | UH-12E | UH-12E-L Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 82-13-04 R1 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4454 AD NUMBER: 82-13-04 R1 SUBJECT HEADING: Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters ACTION: SUMMARY: DATES: Effective September 13, 1982. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 82-13-04 R1 HILLER AVIATION: Amendment 39-4400 as amended by Amendment 39- 4454. Applies to Model UH-12E and UH-12L series helicopters certificated in all categories (including military Models OH-23F and OH-23G) equipped with torsional couplings P/N 21047- 9 and -11 serial numbers 497 through 766. Compliance required within the next 50 hours' time in service after the effective date of this AD or within 300 hours' time in service since September 8, 1980, whichever occurs earlier, unless already accomplished, and thereafter at intervals not to exceed 300 hours' time in service since the last inspection. To prevent possible loss of driving torque to the helicopter rotor system, accomplish this following: (a) Inspect the P/N 21047-9 and 21047-11 torsional couplings as specified in paragraph 2 of Hiller Aviation Service Bulletin UH-12-21-1, Revision 2, dated April 2, 1982 (after this referred to as SB UH-12-21-1), or FAA approved equivalent. (b) If torsional coupling is found to be serviceable, reinstall per paragraph 2 of SB UH-12-21-1 or FAA approved equivalent and revert to the repetitive inspection schedule of this AD. (c) If torsional coupling installation does not meet the inspection requirements of paragraph (a) of this AD, replace with like serviceable part(s) and revert to the repetitive inspection schedule of this AD. (d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate helicopters to a base for the accomplishment of inspections required by this AD. (e) Alternative inspections, modifications, or other actions which provide an equivalent level of safety may be used when approved by the Chief, Western Aircraft Certification Field Office, FAA Northwest Mountain Region. NOTE: Hiller Model UH-12 series helicopters converted to turbine power by STC SH178WE or SH177WE do not incorporate the subject parts and therefore are not affected by this AD unless restored to the original configuration. This supersedes Amendment 39-3907 (45 FR 59138), AD 80-18-13. Amendment 39-4400 became effective July 1, 1982. This amendment 39-4454 becomes effective September 13, 1982. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_82-13-04_R.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 82-13-04 R1 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters Subject: Torsional Couplings Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 09/13/1982 Make: Hiller Aviation | Siam Hiller Holdings, Inc. Model: UH-12L | UH-12L4 | UH-12E | UH-12E-L Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 82-13-04 R1 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4454 AD NUMBER: 82-13-04 R1 SUBJECT HEADING: Airworthiness Directives; HILLER AVIATION Model UH-12E and UH-12L Series Helicopters ACTION: SUMMARY: DATES: Effective September 13, 1982. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 82-13-04 R1 HILLER AVIATION: Amendment 39-4400 as amended by Amendment 39- 4454. Applies to Model UH-12E and UH-12L series helicopters certificated in all categories (including military Models OH-23F and OH-23G) equipped with torsional couplings P/N 21047- 9 and -11 serial numbers 497 through 766. Compliance required within the next 50 hours' time in service after the effective date of this AD or within 300 hours' time in service since September 8, 1980, whichever occurs earlier, unless already accomplished, and thereafter at intervals not to exceed 300 hours' time in service since the last inspection. To prevent possible loss of driving torque to the helicopter rotor system, accomplish this following: (a) Inspect the P/N 21047-9 and 21047-11 torsional couplings as specified in paragraph 2 of Hiller Aviation Service Bulletin UH-12-21-1, Revision 2, dated April 2, 1982 (after this referred to as SB UH-12-21-1), or FAA approved equivalent. (b) If torsional coupling is found to be serviceable, reinstall per paragraph 2 of SB UH-12-21-1 or FAA approved equivalent and revert to the repetitive inspection schedule of this AD. (c) If torsional coupling installation does not meet the inspection requirements of paragraph (a) of this AD, replace with like serviceable part(s) and revert to the repetitive inspection schedule of this AD. (d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate helicopters to a base for the accomplishment of inspections required by this AD. (e) Alternative inspections, modifications, or other actions which provide an equivalent level of safety may be used when approved by the Chief, Western Aircraft Certification Field Office, FAA Northwest Mountain Region. NOTE: Hiller Model UH-12 series helicopters converted to turbine power by STC SH178WE or SH177WE do not incorporate the subject parts and therefore are not affected by this AD unless restored to the original configuration. This supersedes Amendment 39-3907 (45 FR 59138), AD 80-18-13. Amendment 39-4400 became effective July 1, 1982. This amendment 39-4454 becomes effective September 13, 1982. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.