AD 81-09-08

final rule

Airworthiness Directives; HILLER AVIATION Models UH-12D, UH-12E and UH-12E4 Series Helicopters

AD Number
81-09-08
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of a helicopter rotor hub assembly
Problem area Rotor system

Applicability

TypeManufacturerModelDetails
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12D Airworthiness Directives; HILLER AVIATION Models UH-12D, UH-12E and UH-12E4 Series Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12E Airworthiness Directives; HILLER AVIATION Models UH-12D, UH-12E and UH-12E4 Series Helicopters

Unsafe Condition

Main rotor blade failure due to delamination of the skin at the blade tip.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Remove blade tip cap and visually inspect for skin bond separation in the tip cap area per Hiller Aviation Service Bulletin No. 51-8 dated March 25, 1981. If separation is detected, replace blade or repair with FAA approval. If no separation, replace tip cap and seal per the same service bulletin.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Prior to further flight after the effective date of this AD or receipt of the priority mail AD 81-09-08 issued April 27, 1981, whichever occurs first.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Hiller Aviation and Siam Hiller Holdings, Inc. Models UH-12D, UH-12E, UH-12E4 Series Helicopters, including military Models H-23F, OH-23G, and all models converted by STC SH178WE and STC SH177WE, equipped with main rotor blades Part No. 53200-03.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Main Rotor Blade

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_81-09-08.html
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AD Number:
81-09-08
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; HILLER AVIATION Models UH-12D, UH-12E and UH-12E4 Series Helicopters
Subject:
Main Rotor Blade
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/25/1981
Make:
Hiller Aviation | Siam Hiller Holdings, Inc.
Model:
UH-12D | UH-12E
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: 81-09-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4137

AD NUMBER:   81-09-08

SUBJECT HEADING:   Airworthiness Directives; HILLER AVIATION Models UH-12D, UH-12E and UH-12E4 Series Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective June 25, 1981.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-09-08 HILLER AVIATION: Amendment 39-4137. Applies to Models UH-12D, UH-12E, UH-12E4 Series Helicopters, including military Models H-23F, OH-23G, and all models converted by STC SH178WE and STC SH177WE, equipped with main rotor blades Part No. 53200-03, certified in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent possible main rotor blade failure due to the delamination of the skin at the blade tip, accomplish the following:

(a) Prior to further flight, after the effective date of this AD or receipt of the priority mail AD 81-09-08, issued April 27, 1981, whichever occurs first:

(1) Remove blade tip cap and visually inspect for skin bond separation in the tip cap area, in accordance with Para. II.D of Hiller Aviation Service Bulletin No. 51-8 dated March 25, 1981.

(2) If the skin bond separation is detected, replace blade with like serviceable item or repair in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region. Submit data defining exact areas of delamination when requesting repair approval.

(3) If no skin bond separation is detected, replace the tip cap and seal, in accordance with Para. II.F of Hiller Aviation Service Bulletin No. 51-8, dated March 25, 1981.

(b) Upon the effective date or upon receipt of the priority mail AD 81-09-08, issued April 27, 1981, whichever occurs first, whenever the rotor blade tip cap is removed for whatever reason, comply with the inspection requirements and tip cap reinstallation requirements of Para. (a) of this AD prior to return to service.

Special flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate helicopters to a base for the accomplishment of inspections or modifications required by this AD.

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.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein, and made a part hereof pursuant to 5 U.S.C. 553(a)(1). All persons affected by this directive, who have not already received these documents from the manufacturer, may obtain copies upon request to Hiller Aviation, 2075 West Scranton Avenue, Porterville, California 93275. These documents may also be examined at FAA Western Region Office, Rules Docket, Room 6W14, 15000 Aviation Boulevard, Hawthorne, California 90261 and at FAA Headquarters, Rules Docket, Room 916, 800 Independence Avenue, S.W., Washington, D.C. 20591.

A historical file on this AD, which includes the incorporated material in full, is maintained by the FAA Headquarters in Washington, D.C. and the FAA Western Region Office.

This amendment becomes effective June 25, 1981 to all persons, except those to whom it was made immediately effective by priority mail AD 81-09-08, issued April 27, 1981.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_81-09-08.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
81-09-08
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; HILLER AVIATION Models UH-12D, UH-12E and UH-12E4 Series Helicopters
Subject:
Main Rotor Blade
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/25/1981
Make:
Hiller Aviation | Siam Hiller Holdings, Inc.
Model:
UH-12D | UH-12E
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: 81-09-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4137

AD NUMBER:   81-09-08

SUBJECT HEADING:   Airworthiness Directives; HILLER AVIATION Models UH-12D, UH-12E and UH-12E4 Series Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective June 25, 1981.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-09-08 HILLER AVIATION: Amendment 39-4137. Applies to Models UH-12D, UH-12E, UH-12E4 Series Helicopters, including military Models H-23F, OH-23G, and all models converted by STC SH178WE and STC SH177WE, equipped with main rotor blades Part No. 53200-03, certified in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent possible main rotor blade failure due to the delamination of the skin at the blade tip, accomplish the following:

(a) Prior to further flight, after the effective date of this AD or receipt of the priority mail AD 81-09-08, issued April 27, 1981, whichever occurs first:

(1) Remove blade tip cap and visually inspect for skin bond separation in the tip cap area, in accordance with Para. II.D of Hiller Aviation Service Bulletin No. 51-8 dated March 25, 1981.

(2) If the skin bond separation is detected, replace blade with like serviceable item or repair in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region. Submit data defining exact areas of delamination when requesting repair approval.

(3) If no skin bond separation is detected, replace the tip cap and seal, in accordance with Para. II.F of Hiller Aviation Service Bulletin No. 51-8, dated March 25, 1981.

(b) Upon the effective date or upon receipt of the priority mail AD 81-09-08, issued April 27, 1981, whichever occurs first, whenever the rotor blade tip cap is removed for whatever reason, comply with the inspection requirements and tip cap reinstallation requirements of Para. (a) of this AD prior to return to service.

Special flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate helicopters to a base for the accomplishment of inspections or modifications required by this AD.

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.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein, and made a part hereof pursuant to 5 U.S.C. 553(a)(1). All persons affected by this directive, who have not already received these documents from the manufacturer, may obtain copies upon request to Hiller Aviation, 2075 West Scranton Avenue, Porterville, California 93275. These documents may also be examined at FAA Western Region Office, Rules Docket, Room 6W14, 15000 Aviation Boulevard, Hawthorne, California 90261 and at FAA Headquarters, Rules Docket, Room 916, 800 Independence Avenue, S.W., Washington, D.C. 20591.

A historical file on this AD, which includes the incorporated material in full, is maintained by the FAA Headquarters in Washington, D.C. and the FAA Western Region Office.

This amendment becomes effective June 25, 1981 to all persons, except those to whom it was made immediately effective by priority mail AD 81-09-08, issued April 27, 1981.

FOOTER:

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Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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