AD 73-12-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Grumman American Aviation Corporation | G-21 | Airworthiness Directives; Grumman Model G-21 and G-21A Type Airplanes |
| aircraft | Grumman American Aviation Corporation | G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B) | Airworthiness Directives; Grumman Model G-21 and G-21A Type Airplanes |
Unsafe Condition
Failure of the elevator torque tube assembly P/N 12755, rudder torque tube assembly P/N 12756, L.H. and R.H. rudder pedal torque tube assemblies P/Ns 12757, 12758, and hinge support assembly P/N 12725 due to cracks and corrosion below the cockpit floor.
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Required Actions
Visually inspect assemblies for cracks and corrosion within one month after the effective date unless done within the last eleven months, then every twelve months. For assemblies with 3000 hours or 36 months in service, disassemble and inspect using visual, dye penetrant, or magnaflux methods within one month after effective date unless done in last 23 months, then every 2000 hours or 24 months. Repair or replace corroded parts and replace cracked parts with new or inspected parts before further flight.
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Compliance Time
Within one month after the effective date of this A.D. unless already accomplished within the last eleven months and thereafter at intervals not to exceed twelve months in service from the last inspection. For assemblies with 3000 hours or 36 months in service: within one month's time in service after the effective date unless already accomplished within the last 23 months and thereafter at intervals of 2000 hours in service but not exceeding 24 months in service.
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Affected Aircraft
Grumman Models G-21 and G-21A Type Airplanes (Army OA-9, Navy JRF-1 through JRF-6B under TC654)
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Federal Register Abstract
Elevator and Rudder Torque Tube Failure
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_73-12-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-12-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Grumman Model G-21 and G-21A Type Airplanes Subject: Elevator and Rudder Torque Tube Failure Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/14/1973 Make: Grumman American Aviation Corporation Model: G-21 | G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 73-12-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1657 AD NUMBER: 73-12-06 SUBJECT HEADING: Airworthiness Directives; Grumman Model G-21 and G-21A Type Airplanes ACTION: SUMMARY: DATES: Effective June 14, 1973. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-12-06 GRUMMAN: Amdt. 39-1657. Applies to Grumman Models G-21 and G-21A Type Airplanes (Army OA-9, Navy, JRF-1 through JRF-6B under TC654) certificated in all categories. Compliance required as indicated: 1. To prevent hazards in flight associated with the failure of the elevator torque tube assembly P/N 12755, rudder torque tube assembly P/N 12756, L.H. and R.H. rudder pedal torque tube assemblies P/N's 12757, 12758 and hinge support assembly P/N 12725, located below the cockpit floor, visually inspect these assemblies for cracks and corrosion within one month after the effective date of this A.D. unless already accomplished within the last eleven months and thereafter at intervals not to exceed twelve months in service from the last inspection. 2. On assemblies having 3000 hours or more time in service or exceeding 36 months in service, within one month's time in service after the effective date of this A.D. unless already accomplished within the last 23 months and thereafter at intervals of 2000 hours in service but not exceeding 24 months in service, remove and disassemble the elevator torque tube assembly P/N 12755, rudder torque tube assembly P/N 12756, the L.H. and R.H. rudder pedal torque tube assembly P/N's 12757 and 12758, and hinge support assembly P/N 12725. Inspect all parts for corrosion or cracks, using visual and dye penetrant or magnaflux inspection methods. 3. Before further flight, repair or replace corroded parts and replace cracked parts with new parts or with a used part inspected in accordance with this AD or with an equivalent part approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region, except that the aircraft may be flown in accordance with FAR 21.197. 4. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Southern Region, may adjust the repetitive inspection interval specified in this AD. This AD supersedes AD 72-13-05. This amendment is effective June 14, 1973. FOOTER:
Document Text
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AD Final Rules - DRS_73-12-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-12-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Grumman Model G-21 and G-21A Type Airplanes Subject: Elevator and Rudder Torque Tube Failure Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/14/1973 Make: Grumman American Aviation Corporation Model: G-21 | G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 73-12-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1657 AD NUMBER: 73-12-06 SUBJECT HEADING: Airworthiness Directives; Grumman Model G-21 and G-21A Type Airplanes ACTION: SUMMARY: DATES: Effective June 14, 1973. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-12-06 GRUMMAN: Amdt. 39-1657. Applies to Grumman Models G-21 and G-21A Type Airplanes (Army OA-9, Navy, JRF-1 through JRF-6B under TC654) certificated in all categories. Compliance required as indicated: 1. To prevent hazards in flight associated with the failure of the elevator torque tube assembly P/N 12755, rudder torque tube assembly P/N 12756, L.H. and R.H. rudder pedal torque tube assemblies P/N's 12757, 12758 and hinge support assembly P/N 12725, located below the cockpit floor, visually inspect these assemblies for cracks and corrosion within one month after the effective date of this A.D. unless already accomplished within the last eleven months and thereafter at intervals not to exceed twelve months in service from the last inspection. 2. On assemblies having 3000 hours or more time in service or exceeding 36 months in service, within one month's time in service after the effective date of this A.D. unless already accomplished within the last 23 months and thereafter at intervals of 2000 hours in service but not exceeding 24 months in service, remove and disassemble the elevator torque tube assembly P/N 12755, rudder torque tube assembly P/N 12756, the L.H. and R.H. rudder pedal torque tube assembly P/N's 12757 and 12758, and hinge support assembly P/N 12725. Inspect all parts for corrosion or cracks, using visual and dye penetrant or magnaflux inspection methods. 3. Before further flight, repair or replace corroded parts and replace cracked parts with new parts or with a used part inspected in accordance with this AD or with an equivalent part approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region, except that the aircraft may be flown in accordance with FAR 21.197. 4. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Southern Region, may adjust the repetitive inspection interval specified in this AD. This AD supersedes AD 72-13-05. This amendment is effective June 14, 1973. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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