AD 56-25-02

final rule

Airworthiness Directives; Bell Model 47 Series Helicopters

AD Number
56-25-02
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 Scotts-Bell 47 Inc 47 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47B Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47B3 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47D Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47D1 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47E Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-2 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-2A Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-2A-1 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-3 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-3B Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-3B-1 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-3B-2 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-3B-2A Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-4 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-4A Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-5 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47G-5A Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47H-1 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47J Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47J-2 Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47J-2A Airworthiness Directives; Bell Model 47 Series Helicopters
aircraft Scotts-Bell 47 Inc 47K Airworthiness Directives; Bell Model 47 Series Helicopters

Unsafe Condition

Excessive tolerance resulting from wear of the tail rotor pitch change rod assembly can result in the loss of the S1RP or 7R4AX1C bearings.

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

Required Actions

Replace AN 960-416 washers or washers P/N 47-641-113-1 with washers having an O.D. dimension not greater than 0.552 inch or less than 0.549 inch.

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

Compliance Time

Compliance required by December 22, 1956.

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

Affected Aircraft

All Model 47 Series Helicopters Except the Following: Model 47G Serial Numbers 1529, 1530, 1687 and Up; Model 47G2 Serial Numbers 1505, 1506, 1508, 1617 and Up; Model 47H1 Serial Numbers 1369, 1371 and Up; Model 47J.

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

Federal Register Abstract

Tail Rotor Pitch Bearings

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_56-25-02.html
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AD Number:
56-25-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Bell Model 47 Series Helicopters
Subject:
Tail Rotor Pitch Bearings
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Scotts-Bell 47 Inc
Model:
47 | 47B | 47B3 | 47D | 47D1 | 47E | 47G | 47G-2 | 47G-2A | 47G-2A-1 | 47G-3 | 47G-3B | 47G-3B-1 | 4...Show more
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: 56-25-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   56-25-02

SUBJECT HEADING:   Airworthiness Directives; Bell Model 47 Series Helicopters

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
56-25-02 BELL: Applies to All Model 47 Series Helicopters Except the Following: Model 47G Serial Numbers 1529, 1530, 1687 and Up; Model 47G2 Serial Numbers 1505, 1506, 1508, 1617 and Up; Model 47H1 Serial Numbers 1369, 1371 and Up; Model 47J.

Compliance required by December 22, 1956.

Excessive tolerance resulting from wear of the tail rotor pitch change rod assembly can result in the loss of the S1RP or 7R4AX1C bearings. To preclude loss of these bearings, the AN 960-416 washer or washers, P/N 47-641-113-1, made to the dimensions 0.562-0.557 inch must be replaced with washers that have an O.D. dimension not greater than 0.552 inch or less than 0.549 inch.

(Bell Mandatory Service Bulletin No. 113 Revision B dated October 23, 1956, covers this same subject.)
This supersedes AD 56-20-02.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_56-25-02.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
56-25-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Bell Model 47 Series Helicopters
Subject:
Tail Rotor Pitch Bearings
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Scotts-Bell 47 Inc
Model:
47 | 47B | 47B3 | 47D | 47D1 | 47E | 47G | 47G-2 | 47G-2A | 47G-2A-1 | 47G-3 | 47G-3B | 47G-3B-1 | 4...Show more
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: 56-25-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   56-25-02

SUBJECT HEADING:   Airworthiness Directives; Bell Model 47 Series Helicopters

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
56-25-02 BELL: Applies to All Model 47 Series Helicopters Except the Following: Model 47G Serial Numbers 1529, 1530, 1687 and Up; Model 47G2 Serial Numbers 1505, 1506, 1508, 1617 and Up; Model 47H1 Serial Numbers 1369, 1371 and Up; Model 47J.

Compliance required by December 22, 1956.

Excessive tolerance resulting from wear of the tail rotor pitch change rod assembly can result in the loss of the S1RP or 7R4AX1C bearings. To preclude loss of these bearings, the AN 960-416 washer or washers, P/N 47-641-113-1, made to the dimensions 0.562-0.557 inch must be replaced with washers that have an O.D. dimension not greater than 0.552 inch or less than 0.549 inch.

(Bell Mandatory Service Bulletin No. 113 Revision B dated October 23, 1956, covers this same subject.)
This supersedes AD 56-20-02.

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.