AD 78-22-02

final rule

Airworthiness Directives; Hiller Model UH-12D, UH-12E, UH-23D, UH-23G, and H-23F Helicopters

AD Number
78-22-02
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 Model UH-12D, UH-12E, UH-23D, UH-23G, and H-23F Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12E Airworthiness Directives; Hiller Model UH-12D, UH-12E, UH-23D, UH-23G, and H-23F Helicopters

Unsafe Condition

Failure of the main rotor blade Parson Part No. 2253-1101-03 and 2253-1101-04 antinode outboard retention system could result in a loss of the rotorcraft.

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

Required Actions

Inspect the threaded end of the antinode bar outboard of the antinode weight anchor nut. If the thread major diameter is ≤0.3677 inches, replace the antinode bar assembly either by returning blades to Hiller Aviation/FAA-approved repair station or following Hiller Service Bulletin 51-4. Record measurements and report helicopter/blade details to FAA Western Region.

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

Compliance Time

Before further flight after receipt of this AD

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

Affected Aircraft

Hiller Model UH-12D, UH-12E, UH-23D, UH-23G, H-23F helicopters equipped with main rotor blades assembly Parson Part No. 2253-1101-03 or 2253-1101-04.

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

Federal Register Abstract

Rotor Blade Retention System

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_78-22-02.html
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AD Number:
78-22-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Hiller Model UH-12D, UH-12E, UH-23D, UH-23G, and H-23F Helicopters
Subject:
Rotor Blade Retention System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/27/1978
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: 78-22-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3320

AD NUMBER:   78-22-02

SUBJECT HEADING:   Airworthiness Directives; Hiller Model UH-12D, UH-12E, UH-23D, UH-23G, and H-23F Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective October 27, 1978.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
78-22-02 HILLER HELICOPTER: Amendment 39-3320. Applies to Hiller Model UH- 12D, UH-12E, and UH-12E(4 Place) certificated in all categories including Military Models UH- 23D, UH-23G, H-23F and turbine powered models, equipped with main rotor blades assembly, Parson Part No. 2253-1101-03 or 2253-1101-04.

Compliance required as indicated.

To prevent failure of the main rotor blade Parson Part No. 2253-1101-03 and 2253-1101- 04 antinode outboard retention system, which could result in a loss of the rotorcraft, accomplish the following:

(a) Before further flight after receipt of this AD, unless already accomplished, inspect the threaded end of the antinode bar outboard of the antinode weight anchor nut according to the following instructions:

(1) Remove the antinode bar assembly per paragraph 4.53 of UH-12E/UH- 12L Series Structural Repair Manual.

(2) Clean thread outboard of the antinode weight anchor nut with a suitable wire brush.

(3) Using a micrometer, measure the thread major diameter.

(i) If the rod thread major diameter is between .3678 and .3750 inches, no further action is required for this AD and the rod may be reinstalled per instructions contained in the Structural Repair Manual.

NOTE: CAUTION. Use extreme care in reinstalling the antinode bar assembly to ensure that the screws attaching the anchor nut to the antinode bar are not sheared. Hand pressure is the maximum force allowed.

(ii) If the rod thread major diameter measures .3677 inch or less, before returning to service:

(A) Return the rotor blade(s) to Hiller Aviation or an FAA approved repair station to replace the antinode bar assembly, or

(B) Replace the antinode bar assembly per Hiller Service Bulletin 51-4 dated September 26, 1978.

NOTE: Hiller Service Bulletin 51-4 dated September 26, 1978 is the only version of the service bulletin suitable for compliance with this AD.

(b) Special flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate aircraft to a base for accomplishment of the repair required by paragraph (a) of this AD.

(c) Equivalent inspection procedures and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(d) Record the rod thread major diameter on the appropriate blade record card.

(e) Report the helicopter serial number, blade serial number, blade total time and the antinode rod thread major diameter to the Chief, Aircraft Engineering Division, FAA Western Region, P.O. Box 92007, World Way Postal Center, Los Angeles, Ca 90009. (Reporting approved by the Bureau of the Budget under BOB No. 04-R0174.)

This amendment is effective October 27, 1978 and was effective upon receipt for all recipients of the priority mail letter dated September 22, 1978 which contained this amendment.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_78-22-02.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
78-22-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Hiller Model UH-12D, UH-12E, UH-23D, UH-23G, and H-23F Helicopters
Subject:
Rotor Blade Retention System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/27/1978
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: 78-22-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3320

AD NUMBER:   78-22-02

SUBJECT HEADING:   Airworthiness Directives; Hiller Model UH-12D, UH-12E, UH-23D, UH-23G, and H-23F Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective October 27, 1978.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
78-22-02 HILLER HELICOPTER: Amendment 39-3320. Applies to Hiller Model UH- 12D, UH-12E, and UH-12E(4 Place) certificated in all categories including Military Models UH- 23D, UH-23G, H-23F and turbine powered models, equipped with main rotor blades assembly, Parson Part No. 2253-1101-03 or 2253-1101-04.

Compliance required as indicated.

To prevent failure of the main rotor blade Parson Part No. 2253-1101-03 and 2253-1101- 04 antinode outboard retention system, which could result in a loss of the rotorcraft, accomplish the following:

(a) Before further flight after receipt of this AD, unless already accomplished, inspect the threaded end of the antinode bar outboard of the antinode weight anchor nut according to the following instructions:

(1) Remove the antinode bar assembly per paragraph 4.53 of UH-12E/UH- 12L Series Structural Repair Manual.

(2) Clean thread outboard of the antinode weight anchor nut with a suitable wire brush.

(3) Using a micrometer, measure the thread major diameter.

(i) If the rod thread major diameter is between .3678 and .3750 inches, no further action is required for this AD and the rod may be reinstalled per instructions contained in the Structural Repair Manual.

NOTE: CAUTION. Use extreme care in reinstalling the antinode bar assembly to ensure that the screws attaching the anchor nut to the antinode bar are not sheared. Hand pressure is the maximum force allowed.

(ii) If the rod thread major diameter measures .3677 inch or less, before returning to service:

(A) Return the rotor blade(s) to Hiller Aviation or an FAA approved repair station to replace the antinode bar assembly, or

(B) Replace the antinode bar assembly per Hiller Service Bulletin 51-4 dated September 26, 1978.

NOTE: Hiller Service Bulletin 51-4 dated September 26, 1978 is the only version of the service bulletin suitable for compliance with this AD.

(b) Special flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate aircraft to a base for accomplishment of the repair required by paragraph (a) of this AD.

(c) Equivalent inspection procedures and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(d) Record the rod thread major diameter on the appropriate blade record card.

(e) Report the helicopter serial number, blade serial number, blade total time and the antinode rod thread major diameter to the Chief, Aircraft Engineering Division, FAA Western Region, P.O. Box 92007, World Way Postal Center, Los Angeles, Ca 90009. (Reporting approved by the Bureau of the Budget under BOB No. 04-R0174.)

This amendment is effective October 27, 1978 and was effective upon receipt for all recipients of the priority mail letter dated September 22, 1978 which contained this amendment.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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