AD 55-17-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Aircraft Corporation | 1049-54 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 1049B-55 (Navy R7V-1) | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 1049C-55 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 1049D-55 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 1049E-55 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 1049F-55 (USAF C-121C) | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 1049G-82 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 149-46 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 49-46 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 649-79 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 649A-79 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 749-79 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
| aircraft | Lockheed Aircraft Corporation | 749A-79 | LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes |
Unsafe Condition
Failure of wing flap torque tube assembly due to defective bolt P/N AN 23-19, suspected caused by initial overtorque.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect bolts P/N AN 23-19 on wing flap torque tubes to ensure proper installation and torque (10 to 20 inch-pounds). Replace overtorqued bolts and consider using P/N AN23-20 bolts or washers within specified limits if needed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
December 1, 1955, unless already accomplished
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Lockheed Models 49, 149, 649, 749, and 1049 airplanes
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Flap Torque Tube Bolts
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_55-17-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 55-17-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes Subject: Flap Torque Tube Bolts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Lockheed Aircraft Corporation Model: 1049-54 | 1049B-55 (Navy R7V-1) | 1049C-55 | 1049D-55 | 1049E-55 | 1049F-55 (USAF C-121C) | 1049G-82...Show more 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: 49, 149, 649, 749, and 1049 AIRWORTHINESS DIRECTIVES FINAL RULES: 55-17-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 55-17-01 SUBJECT HEADING: LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 55-17-01 LOCKHEED: Applies to All Models 49, 149, 649, 749, and 1049 Airplanes. Compliance required by December 1, 1955, unless already accomplished. A recent failure of wing flap torque tube assembly, P/N 326605-3, on a Model 1049C is attributed to a defective bolt, P/N AN 23-19. Initial overtorque of the bolt is suspected as the cause of failure of the bolt. It is therefore necessary that all Constellation and Super Constellation airplanes be inspected to ascertain proper installation of bolts, including bolt torque, on all wing flap torque tubes. Proper torque value for the AN 23-19 bolts is 10 to 20 inch-pounds. Nut torque must be checked with a torque wrench and all overtorqued bolts replaced. If necessary, the next size longer bolt (P/N AN23-20) may be used to facilitate installation within proper torque tolerances. Washers may be used as required, but not to exceed two under the head or two under the nut, to prevent the nut from bottoming on the shank. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_55-17-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 55-17-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes Subject: Flap Torque Tube Bolts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Lockheed Aircraft Corporation Model: 1049-54 | 1049B-55 (Navy R7V-1) | 1049C-55 | 1049D-55 | 1049E-55 | 1049F-55 (USAF C-121C) | 1049G-82...Show more 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: 49, 149, 649, 749, and 1049 AIRWORTHINESS DIRECTIVES FINAL RULES: 55-17-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 55-17-01 SUBJECT HEADING: LOCKHEED Models 49, 149, 649, 749, and 1049 Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 55-17-01 LOCKHEED: Applies to All Models 49, 149, 649, 749, and 1049 Airplanes. Compliance required by December 1, 1955, unless already accomplished. A recent failure of wing flap torque tube assembly, P/N 326605-3, on a Model 1049C is attributed to a defective bolt, P/N AN 23-19. Initial overtorque of the bolt is suspected as the cause of failure of the bolt. It is therefore necessary that all Constellation and Super Constellation airplanes be inspected to ascertain proper installation of bolts, including bolt torque, on all wing flap torque tubes. Proper torque value for the AN 23-19 bolts is 10 to 20 inch-pounds. Nut torque must be checked with a torque wrench and all overtorqued bolts replaced. If necessary, the next size longer bolt (P/N AN23-20) may be used to facilitate installation within proper torque tolerances. Washers may be used as required, but not to exceed two under the head or two under the nut, to prevent the nut from bottoming on the shank. 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
93-14-12
final ruleAirworthiness Directives; ESSEX PB&R CORPORATION (formerly E.I. DuPont de Nemours and Company \\nIncorporated) PELS Model 4566M37B Crewmember Protective Breathing Equipment (PBE) Units
Unsafe Condition: Leakage of the PBE neck seal could compromise the crew's ability to combat an aircraft fire.
71-07-02
final ruleLOCKHEED Models 49, 149, 649, 749, 1049, and 1649 Series Airplanes
Unsafe Condition: Failure to provide an acceptable obstacle clearance profile when computing the takeoff flight path.
67-03-05
final ruleLOCKHEED Models 649, 749, and 1049 Airplanes
Unsafe Condition: Propeller vibratory stresses due to continuous ground running between 2,300 and 2,650 r.p.m. with propeller governing and continuous static ground running in a crosswind above 2,650 r.p.m.
64-13-03
final ruleLOCKHEED Models 49, 149, 649, 649A, 749, 749A, 1049-54, 1049C, 1049D, 1049E, 1049G, and 1049H Series Aircraft
Unsafe Condition: Cracks and failure in the nose landing gear retract cylinder rod terminal ends (P/N 404052 or 1005032) due to fatigue.
