AD 61-21-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bombardier Inc. | CL-44D4 | Airworthiness Directives; CANADAIR Model CL-44D4 Aircraft |
Unsafe Condition
Failure of the tail pipe door structure due to fatigue cracking in the attachment holes of specific tail pipe compartment access panels.
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Required Actions
Inspect tail pipe compartment access panels with specified part numbers for fatigue cracking using dye penetrant or equivalent. Replace, repair, or reinforce cracked panels per Canadair Service Bulletin CL-44D4-138 or approved modification. Continue inspections at intervals not exceeding 35 hours' time in service if interim repairs are made. Discontinue inspections after approved modification.
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Compliance Time
Within the next 25 hours' time in service unless already accomplished within the last 10 hours' time in service and at intervals not to exceed 35 hours' time in service.
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Affected Aircraft
Bombardier Inc. Model CL-44D4 Aircraft, Serial Numbers 14, 16, 19 through 23, 25 and 26.
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Federal Register Abstract
Tail Pipe Door
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_61-21-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-21-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CANADAIR Model CL-44D4 Aircraft Subject: Tail Pipe Door Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/17/1961 Make: Bombardier Inc. Model: CL-44D4 Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 61-21-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-21-01 SUBJECT HEADING: Airworthiness Directives; CANADAIR Model CL-44D4 Aircraft ACTION: SUMMARY: DATES: Effective October 17, 1961. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-21-01 CANADAIR: Amdt. 348 Part 507 Federal Register October 17, 1961. Applies to Model CL-44D4 Aircraft, Serial Numbers 14, 16, 19 through 23, 25 and 26. Compliance required within the next 25 hours' time in service unless already accomplished within the last 10 hours' time in service and at intervals not to exceed 35 hours' time in service. To preclude failure of the tail pipe door structure, the following must be accomplished: (a) Inspect the following tail pipe compartment access panels for fatigue cracking using dye penetrant or equivalent in the area of the attachment holes. Part Numbers to be inspected are 44-10721, 44-10721-1, 44-10722, 44-10722-1, 44-10726, 44-10721-990, 44- 10721-991, 44-10722-990, 44-10722-991, 44-10726-990, 44-10751, 44-10751-1, 44-10752, 44- 10752-1, and 44-10753. (b) If cracks are found, panels must be replaced, repaired or reinforced in accordance with Canadair Service Bulletin No. CL-44D4-138 or equivalent, or modified in accordance with a Department of Transport and FAA approved modification prior to further flight except ferry flight in accordance with the provisions of CAR 1.76. Following the incorporation of the interim repair or reinforcement covered in Service Bulletin No. CL-44D4- 138, or replacement, the inspections specified in (a) must be continued at intervals not exceeding 35 hours' time in service. If further cracks are found after repair or reinforcement per Canadair Service Bulletin CL-44D4-138, the parts shall be replaced or modified in accordance with Canadian Department of Transport and FAA approved modification. (c) The special inspections required by this airworthiness directive may be discontinued after incorporation of the Canadian Department of Transport and FAA approved modification of the affected parts. (d) Upon request of the operator, an FAA maintenance inspector, subject to approval of the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator. This directive effective October 17, 1961. FOOTER:
Document Text
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AD Final Rules - DRS_61-21-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-21-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CANADAIR Model CL-44D4 Aircraft Subject: Tail Pipe Door Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/17/1961 Make: Bombardier Inc. Model: CL-44D4 Product Type: Aircraft Product Subtype: Large 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: 61-21-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-21-01 SUBJECT HEADING: Airworthiness Directives; CANADAIR Model CL-44D4 Aircraft ACTION: SUMMARY: DATES: Effective October 17, 1961. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-21-01 CANADAIR: Amdt. 348 Part 507 Federal Register October 17, 1961. Applies to Model CL-44D4 Aircraft, Serial Numbers 14, 16, 19 through 23, 25 and 26. Compliance required within the next 25 hours' time in service unless already accomplished within the last 10 hours' time in service and at intervals not to exceed 35 hours' time in service. To preclude failure of the tail pipe door structure, the following must be accomplished: (a) Inspect the following tail pipe compartment access panels for fatigue cracking using dye penetrant or equivalent in the area of the attachment holes. Part Numbers to be inspected are 44-10721, 44-10721-1, 44-10722, 44-10722-1, 44-10726, 44-10721-990, 44- 10721-991, 44-10722-990, 44-10722-991, 44-10726-990, 44-10751, 44-10751-1, 44-10752, 44- 10752-1, and 44-10753. (b) If cracks are found, panels must be replaced, repaired or reinforced in accordance with Canadair Service Bulletin No. CL-44D4-138 or equivalent, or modified in accordance with a Department of Transport and FAA approved modification prior to further flight except ferry flight in accordance with the provisions of CAR 1.76. Following the incorporation of the interim repair or reinforcement covered in Service Bulletin No. CL-44D4- 138, or replacement, the inspections specified in (a) must be continued at intervals not exceeding 35 hours' time in service. If further cracks are found after repair or reinforcement per Canadair Service Bulletin CL-44D4-138, the parts shall be replaced or modified in accordance with Canadian Department of Transport and FAA approved modification. (c) The special inspections required by this airworthiness directive may be discontinued after incorporation of the Canadian Department of Transport and FAA approved modification of the affected parts. (d) Upon request of the operator, an FAA maintenance inspector, subject to approval of the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator. This directive effective October 17, 1961. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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