AD 75-22-21
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airbus Helicopters | SA.316B Alouette III | Airworthiness Directives; Societe Nationale Industrielle Aerospatiale: (S.N.I.A.S., formerly SUD AVIATION) Model SA316B Alouette III Helicopters |
Unsafe Condition
Failure of the main gearbox due to incorporation of main rotor transmission gearbox (MGB) with specific part numbers and serial numbers 9,999 or lower, which may require replacement to prevent failure.
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Required Actions
Install a temporary operating limitations placard on the instrument panel within 10 hours' time in service after the effective date. Replace the MGB with a serviceable unit having part numbers specified in Service Bulletin No. 01.34 or FAA-approved equivalent within 450 hours' time in service after the effective date. Remove the placard after completing the MGB replacement.
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Compliance Time
Within the next 10 hours' time in service after the effective date of this AD (for the placard installation) and within the next 450 hours' time in service after the effective date (for the MGB replacement).
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Affected Aircraft
Societe Nationale Industrielle Aerospatiale (S.N.I.A.S.) Model SA316B Alouette III helicopters with main rotor transmission gearbox (MGB) Serial Number 9,999 or lower, P/N 3160S.62.00.000.10 through .12 incorporating Modification AM1212, or P/N 3160S.62.00.000.13 or .14.
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Federal Register Abstract
Main Gear Boxes
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_75-22-21.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 75-22-21 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Societe Nationale Industrielle Aerospatiale: (S.N.I.A.S., formerly SUD AV...Show more Subject: Main Gear Boxes Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/30/1975 Make: Airbus Helicopters Model: SA.316B Alouette III Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 75-22-21 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2393 AD NUMBER: 75-22-21 SUBJECT HEADING: Airworthiness Directives; Societe Nationale Industrielle Aerospatiale: (S.N.I.A.S., formerly SUD AVIATION) Model SA316B Alouette III Helicopters ACTION: SUMMARY: DATES: Effective October 30, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 75-22-21 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE: (S.N.I.A.S., formerly SUD AVIATION). Amendment 39-2393. Applies to Model SA316B Alouette III helicopters, certificated in all categories, incorporating main rotor transmission gearbox (MGB), Serial Number 9,999 or lower, P/N 3160S.62.00.000.10 through .12 incorporating Modification AM1212, or P/N 3160S.62.00.000.13 or .14. Compliance is required as indicated, unless already accomplished. To prevent possible failure of the main gearbox, accomplish the following: (a) Within the next 10 hours' time in service after the effective date of this AD, install a temporary operating limitations placard on the instrument panel in full view of the pilot reading as follows: "Operate in accordance with the limitations specified in the Alouette III SE.3160 Helicopter Flight Manual. Limitations or performance specified in Appendix 2 of that manual are not applicable to this helicopter." (b) Within the next 450 hours' time in service after the effective date of this AD, replace the MGB with a serviceable MGB having a part number specified in Subparagraph 1C of Alouette Service Bulletin No. 01.34 dated June 24, 1974, or an FAA-approved equivalent. (c) After complying with paragraph (b) of this AD, the placard required by paragraph (a) may be removed. This amendment becomes effective October 30, 1975. FOOTER:
Document Text
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AD Final Rules - DRS_75-22-21.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 75-22-21 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Societe Nationale Industrielle Aerospatiale: (S.N.I.A.S., formerly SUD AV...Show more Subject: Main Gear Boxes Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/30/1975 Make: Airbus Helicopters Model: SA.316B Alouette III 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: 75-22-21 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2393 AD NUMBER: 75-22-21 SUBJECT HEADING: Airworthiness Directives; Societe Nationale Industrielle Aerospatiale: (S.N.I.A.S., formerly SUD AVIATION) Model SA316B Alouette III Helicopters ACTION: SUMMARY: DATES: Effective October 30, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 75-22-21 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE: (S.N.I.A.S., formerly SUD AVIATION). Amendment 39-2393. Applies to Model SA316B Alouette III helicopters, certificated in all categories, incorporating main rotor transmission gearbox (MGB), Serial Number 9,999 or lower, P/N 3160S.62.00.000.10 through .12 incorporating Modification AM1212, or P/N 3160S.62.00.000.13 or .14. Compliance is required as indicated, unless already accomplished. To prevent possible failure of the main gearbox, accomplish the following: (a) Within the next 10 hours' time in service after the effective date of this AD, install a temporary operating limitations placard on the instrument panel in full view of the pilot reading as follows: "Operate in accordance with the limitations specified in the Alouette III SE.3160 Helicopter Flight Manual. Limitations or performance specified in Appendix 2 of that manual are not applicable to this helicopter." (b) Within the next 450 hours' time in service after the effective date of this AD, replace the MGB with a serviceable MGB having a part number specified in Subparagraph 1C of Alouette Service Bulletin No. 01.34 dated June 24, 1974, or an FAA-approved equivalent. (c) After complying with paragraph (b) of this AD, the placard required by paragraph (a) may be removed. This amendment becomes effective October 30, 1975. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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