AD 67-29-06

final rule

Airworthiness Directives; Sikorsky Model S-51 Helicopters

AD Number
67-29-06
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 Sikorsky Aircraft Corporation S-51 Airworthiness Directives; Sikorsky Model S-51 Helicopters

Unsafe Condition

Failure of sleeve and tube assembly P/N S535180 could lead to loss of tail rotor power.

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

Required Actions

Perform torsional checks every 50 aircraft hours' time in service, including applying rotor brake, inducing torsional force on tail rotor drive shafting, and inspecting shaft ends for movement. Daily inspect for loose rivets indicated by black fretting residue or movement, and cracks at tube and sleeve joints. Replace assembly if movement or cracks are found; loose rivets may be replaced with specified rivets after drilling holes to specified diameters.

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

Compliance Time

Immediately upon the effective date of this AD and every 50 aircraft hours' time in service thereafter

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

Affected Aircraft

Sikorsky Model S-51 Helicopters, all serial numbers

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

Federal Register Abstract

Tail Rotor Sleeve & Tube Assy

Applicability Source Text

Show captured applicability text from the source AD
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AD Number:
67-29-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Sikorsky Model S-51 Helicopters
Subject:
Tail Rotor Sleeve & Tube Assy
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/31/1967
Make:
Sikorsky Aircraft Corporation
Model:
S-51
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Superseded AD: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Superseded By: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: 67-29-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-502

AD NUMBER:   67-29-06

SUBJECT HEADING:   Airworthiness Directives; Sikorsky Model S-51 Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective October 31, 1967.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   67-29-06 SIKORSKY: Amdt. 39-502 Part 39 Federal Register November 2, 1967. Applies to all S-51 type Helicopters.

Compliance required as indicated unless already accomplished.

To preclude the possibility of loss of tail rotor power due to failure of sleeve and tube assembly, P/N S535180, accomplish the following:

(a) Immediately upon the effective date of this AD and every 50 aircraft hours' time in service thereafter, perform the following torsional check on sleeve and tube assembly P/N S535180 as follows:

1. Apply rotor brake.

2. Induce a torsional force in both clockwise and counter-clockwise directions to tail rotor drive shafting by hand applied light rotational pressure on tail rotor blades.

3. Inspect shaft ends for evidence of movement between end fittings, rivets and tube.

4. If evidence of movement is observed, replace sleeve and tube assembly P/N S535180 with like new or serviceable part.

(b) Following the effective date of this AD daily inspect sleeve and tube assembly P/N S535180 for loose rivets as evidenced by the presence of black fretting residue around rivet heads, or actual movement of the rivets, and the presence of cracks in the areas where the tube and sleeves (adapters) are joined. If cracks are found replace sleeve and tube assembly P/N S535180 with like new or serviceable part. Loose rivets may be replaced by removing the existing rivets, drilling No. 2 (.221) diameter and installing new rivets P/N MS20470-B7-9. Alternate oversize rivets P/N MS20470-B8-10 may be used if holes are drilled to No. F. (.257) diameter.

(c) Upon request, with substantiating data submitted through an FAA maintenance inspector, compliance times may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

(Sikorsky Aircraft telegram to all operators dated September 5, 1967 covers this same subject.)

This amendment effective October 31, 1967.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_67-29-06.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
67-29-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Sikorsky Model S-51 Helicopters
Subject:
Tail Rotor Sleeve & Tube Assy
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/31/1967
Make:
Sikorsky Aircraft Corporation
Model:
S-51
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: 67-29-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-502

AD NUMBER:   67-29-06

SUBJECT HEADING:   Airworthiness Directives; Sikorsky Model S-51 Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective October 31, 1967.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   67-29-06 SIKORSKY: Amdt. 39-502 Part 39 Federal Register November 2, 1967. Applies to all S-51 type Helicopters.

Compliance required as indicated unless already accomplished.

To preclude the possibility of loss of tail rotor power due to failure of sleeve and tube assembly, P/N S535180, accomplish the following:

(a) Immediately upon the effective date of this AD and every 50 aircraft hours' time in service thereafter, perform the following torsional check on sleeve and tube assembly P/N S535180 as follows:

1. Apply rotor brake.

2. Induce a torsional force in both clockwise and counter-clockwise directions to tail rotor drive shafting by hand applied light rotational pressure on tail rotor blades.

3. Inspect shaft ends for evidence of movement between end fittings, rivets and tube.

4. If evidence of movement is observed, replace sleeve and tube assembly P/N S535180 with like new or serviceable part.

(b) Following the effective date of this AD daily inspect sleeve and tube assembly P/N S535180 for loose rivets as evidenced by the presence of black fretting residue around rivet heads, or actual movement of the rivets, and the presence of cracks in the areas where the tube and sleeves (adapters) are joined. If cracks are found replace sleeve and tube assembly P/N S535180 with like new or serviceable part. Loose rivets may be replaced by removing the existing rivets, drilling No. 2 (.221) diameter and installing new rivets P/N MS20470-B7-9. Alternate oversize rivets P/N MS20470-B8-10 may be used if holes are drilled to No. F. (.257) diameter.

(c) Upon request, with substantiating data submitted through an FAA maintenance inspector, compliance times may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

(Sikorsky Aircraft telegram to all operators dated September 5, 1967 covers this same subject.)

This amendment effective October 31, 1967.

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.