AD 52-28-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Scotts-Bell 47 Inc | 47 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47B | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47B3 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47D | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47D1 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47E | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-2 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-2A | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-2A-1 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B-1 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B-2 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B-2A | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-4 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-4A | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-5 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-5A | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47H-1 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47J | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47J-2 | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47J-2A | Airworthiness Directives; Bell 47 Series Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47K | Airworthiness Directives; Bell 47 Series Helicopters |
Unsafe Condition
Tail rotor gearbox shaft, P/N 47-645-077-1, may fail after accumulating 900 hours of operation.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the tail rotor gearbox shaft, P/N 47-645-077-1, when it has accumulated 900 hours of operation.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Compliance required as directed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Scotts-Bell 47 Inc 47, 47B, 47B3, 47D, 47D1, 47E, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, and other 47 Series models with the 47-645-002 Gearbox installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Tail Rotor Gearbox Shaft
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_52-28-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 52-28-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell 47 Series Helicopters Subject: Tail Rotor Gearbox Shaft 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: 52-28-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 52-28-03 SUBJECT HEADING: Airworthiness Directives; Bell 47 Series Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 52-28-03 BELL: Applies to All 47 Series Helicopters With the 47-645-002 Gearbox Installed. Compliance required as directed. Replace the tail rotor gearbox shaft, P/N 47-645-077-1, when it has accumulated 900 hours of operation. (Bell's Mandatory Service Bulletin No. 83, Revision A, dated October 2, 1952, covers this same subject.) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_52-28-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 52-28-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell 47 Series Helicopters Subject: Tail Rotor Gearbox Shaft 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: 52-28-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 52-28-03 SUBJECT HEADING: Airworthiness Directives; Bell 47 Series Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 52-28-03 BELL: Applies to All 47 Series Helicopters With the 47-645-002 Gearbox Installed. Compliance required as directed. Replace the tail rotor gearbox shaft, P/N 47-645-077-1, when it has accumulated 900 hours of operation. (Bell's Mandatory Service Bulletin No. 83, Revision A, dated October 2, 1952, covers this same subject.) 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.
Related Airworthiness Directives
2023-09-09 Recurring
final ruleAirworthiness Directives; Various Airplanes, Helicopters, and Engines
Unsafe Condition: Multiple failures of spot-welded, multi-segment v-band couplings at the tailpipe to the turbocharger exhaust housing flange.
2023-11-07
final ruleAirworthiness Directives; Various Helicopters
Unsafe Condition: unsafe condition on these products.
2009-12-01
final ruleAirworthiness Directives; Bell Helicopter Textron, Inc. Model 47, 47B, 47B3, 47D, 47D1, 47E, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K Helicopters
Unsafe Condition: An incorrectly installed main rotor blade box beam clip (clip) could result in a main rotor blade spar crack, loss of a main rotor blade, and subsequent loss of control of the helicopter.
2005-21-04
final ruleAirworthiness Directives; Bell Helicopter Textron Model 47D1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A and Coastal Helicopters, Inc. Model OH-13H (Tomcat Mark 5A, 6B, 6C) Helicopters
Unsafe Condition: Failure of the scissors assembly or weld assembly scissors bracket past its life limit could result in loss of control of the helicopter.