AD 61-03-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Scotts-Bell 47 Inc | 47J-2 | Airworthiness Directives; Bell Model 47J-2 Helicopters |
Unsafe Condition
Failures of the pinion gear on the inboard end of the P/N 47-620-539-1 cooling fan drive assembly associated with a poor tooth mesh condition.
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Required Actions
Inspect the driven side of pinion gear teeth (P/N 47-620-530-1) by removing the cooling fan drive assembly. Replace gears if conditions defined by Bell Service Bulletin 130SB Figures 2 and 4 are found. Reassemble with specified torque values and perform subsequent inspections at 10, 25, 50, 100, and 300 hours of flight time following gear replacement until a satisfactory wear pattern is maintained through 300 hours.
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Compliance Time
No later than the next 10 hours of flight time after February 22, 1961, and by the completion of the 25 hour, 50 hour, 100 hour, and 300 hour flight time periods subsequent to the initial inspection.
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Affected Aircraft
Scotts-Bell 47 Inc Model 47J-2 helicopters except those equipped with Lycoming VO-540-B1B3 engines (Third Order Torsional Dampers).
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Federal Register Abstract
Pinion Gear
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_61-03-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-03-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47J-2 Helicopters Subject: Pinion Gear Status: Current Citation: Federal Register: February 7, 1961 Citation Publish Date: 02/07/1961 Effective Date: Make: Scotts-Bell 47 Inc Model: 47J-2 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 61-03-01 CITATION: [Federal Register: February 7, 1961] PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-03-01 SUBJECT HEADING: Airworthiness Directives; Bell Model 47J-2 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-03-01 BELL: Amdt. 249 Part 507 Federal Register February 7, 1961. Applies to All Model 47J-2 Helicopters Except Those Equipped With Lycoming VO-540-B1B3 Engines (Third Order Torsional Dampers). Compliance required as indicated. To preclude failures of the pinion gear on the inboard end of the P/N 47-620-539-1 cooling fan drive assembly which are associated with a poor tooth mesh condition, the following inspections and corrective action must be accomplished no later than the next 10 hours of flight time after the effective date of this directive, and by the completion of the 25 hour, 50 hour, 100 hour, and 300 hour flight time periods subsequent to the accomplishment of the initial inspection. Inspections accomplished in accordance with Bell Mandatory Service Bulletin 130SB prior to the effective date of this directive need not be repeated and only those remaining inspections necessary to complete the series are required. (a) Remove cooling fan drive assembly, P/N 47-620-539-1, from transmission in accordance with instructions contained in Bell Model 47J-2 Maintenance and Overhaul Instructions, and inspect driven side of pinion gear teeth (P/N 47-620-530-1). (b) Replace gear if conditions defined by Figure 2 of Bell Service Bulletin 130SB are found. (c) If replacement of the pinion gear is required, further disassembly as necessary and inspection of the cooling fan driving gear (P/N 47-620-207-1) must be conducted. If conditions defined by Figure 4 of Bell Service Bulletin 130SB are found, this gear must also be replaced. (d) If replacement of either gear is required, back lash and gear pattern must be established in accordance with instructions contained in Maintenance and Overhaul Instructions. (e) Reassemble cooling fan drive assembly in accordance with Maintenance and Overhaul Instructions except that nut, P/N 47-620-565-1 shall be torqued to 960 inch-pounds and fan pulley bolt AN 6H5A shall be torqued to 300 inch-pounds. (f) If either or both gears are replaced, perform the above inspections at 10, 25, 50, 100 and 300 hours of flight time following gear replacement. This procedure must be reconducted until a satisfactory wear pattern on the pinion gear and drive gear is maintained through 300 hours of flight time, after which inspections in accordance with this directive may be discontinued. (Bell Mandatory Service Bulletin 130SB covers this same subject.) This directive effective February 22, 1961. Revised May 13, 1961. Revised November 5, 1966. FOOTER:
Document Text
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AD Final Rules - DRS_61-03-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-03-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47J-2 Helicopters Subject: Pinion Gear Status: Current Citation: Federal Register: February 7, 1961 Citation Publish Date: 02/07/1961 Effective Date: Make: Scotts-Bell 47 Inc Model: 47J-2 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: 61-03-01 CITATION: [Federal Register: February 7, 1961] PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-03-01 SUBJECT HEADING: Airworthiness Directives; Bell Model 47J-2 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-03-01 BELL: Amdt. 249 Part 507 Federal Register February 7, 1961. Applies to All Model 47J-2 Helicopters Except Those Equipped With Lycoming VO-540-B1B3 Engines (Third Order Torsional Dampers). Compliance required as indicated. To preclude failures of the pinion gear on the inboard end of the P/N 47-620-539-1 cooling fan drive assembly which are associated with a poor tooth mesh condition, the following inspections and corrective action must be accomplished no later than the next 10 hours of flight time after the effective date of this directive, and by the completion of the 25 hour, 50 hour, 100 hour, and 300 hour flight time periods subsequent to the accomplishment of the initial inspection. Inspections accomplished in accordance with Bell Mandatory Service Bulletin 130SB prior to the effective date of this directive need not be repeated and only those remaining inspections necessary to complete the series are required. (a) Remove cooling fan drive assembly, P/N 47-620-539-1, from transmission in accordance with instructions contained in Bell Model 47J-2 Maintenance and Overhaul Instructions, and inspect driven side of pinion gear teeth (P/N 47-620-530-1). (b) Replace gear if conditions defined by Figure 2 of Bell Service Bulletin 130SB are found. (c) If replacement of the pinion gear is required, further disassembly as necessary and inspection of the cooling fan driving gear (P/N 47-620-207-1) must be conducted. If conditions defined by Figure 4 of Bell Service Bulletin 130SB are found, this gear must also be replaced. (d) If replacement of either gear is required, back lash and gear pattern must be established in accordance with instructions contained in Maintenance and Overhaul Instructions. (e) Reassemble cooling fan drive assembly in accordance with Maintenance and Overhaul Instructions except that nut, P/N 47-620-565-1 shall be torqued to 960 inch-pounds and fan pulley bolt AN 6H5A shall be torqued to 300 inch-pounds. (f) If either or both gears are replaced, perform the above inspections at 10, 25, 50, 100 and 300 hours of flight time following gear replacement. This procedure must be reconducted until a satisfactory wear pattern on the pinion gear and drive gear is maintained through 300 hours of flight time, after which inspections in accordance with this directive may be discontinued. (Bell Mandatory Service Bulletin 130SB covers this same subject.) This directive effective February 22, 1961. Revised May 13, 1961. Revised November 5, 1966. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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