AD 60-07-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Martin-Marietta Corporation | 404 | MARTIN Model 404 Aircraft |
Unsafe Condition
The landing gear lock plunger P/N 404-4088121-3 can jam in the retracted position and flare out into a knife edge, causing cutting action in the forward bushings of the plunger cylinder.
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Required Actions
Replace lock plunger P/N 404-4088121-3 with new P/N 404-4900121-5 on each main landing gear by July 31, 1960. Visually inspect main and nose gear lock plungers at each 320 hours' time in service starting no later than May 15, 1960, for spalling or flaring, and chamfer corners if defects exist.
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Compliance Time
by July 31, 1960
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Affected Aircraft
Martin-Marietta Corporation Model 404 Aircraft, all serial numbers
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Federal Register Abstract
Landing Gear Lock Plunger
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_60-07-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 60-07-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: MARTIN Model 404 Aircraft Subject: Landing Gear Lock Plunger Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Martin-Marietta Corporation Model: 404 Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 60-07-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 60-07-06 SUBJECT HEADING: MARTIN Model 404 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 60-07-06 MARTIN: Amdt. 118 Part 507 Federal Register March 25, 1960. Applies to All Model 404 Aircraft. Compliance required as indicated. Investigation of a recent Model 404 wheels up landing disclosed that the landing gear lock linkage and lock plunger malfunctioned. Inspection of the jury strut revealed that when the lock plunger was pulled back to normal travel limits in operating the "free fall" actuating mechanism to "full travel", the plunger would periodically jam in the retracted position and consequently flare out in the form of a knife edge. Also, cutting action was evident in the forward bushings (in the plunger cylinder) in an area coincident with the two flared edges. To prevent further lock plunger malfunctioning, the following must be accomplished: (a) Replace lock plunger P/N 404-4088121-3 with new lock plunger P/N 404- 4900121-5 on each main landing gear by July 31, 1960. (b) At each 320 hours' time in service commencing not later than May 15, 1960, visually inspect main and nose gear lock plungers for a spalling or flaring condition. Check the lock plunger for free operation. The plunger should be free from dirt, dust, moisture, ice, etc. If spalling or flaring exists, the lock plunger must be chamfered (rounded out) at the corners of the plunger for the full length of the flat area. (Martin Service Bulletin No. 404-260 dated October 30, 1952, partially covers this subject.) FOOTER:
Document Text
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AD Final Rules - DRS_60-07-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 60-07-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: MARTIN Model 404 Aircraft Subject: Landing Gear Lock Plunger Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Martin-Marietta Corporation Model: 404 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: 60-07-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 60-07-06 SUBJECT HEADING: MARTIN Model 404 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 60-07-06 MARTIN: Amdt. 118 Part 507 Federal Register March 25, 1960. Applies to All Model 404 Aircraft. Compliance required as indicated. Investigation of a recent Model 404 wheels up landing disclosed that the landing gear lock linkage and lock plunger malfunctioned. Inspection of the jury strut revealed that when the lock plunger was pulled back to normal travel limits in operating the "free fall" actuating mechanism to "full travel", the plunger would periodically jam in the retracted position and consequently flare out in the form of a knife edge. Also, cutting action was evident in the forward bushings (in the plunger cylinder) in an area coincident with the two flared edges. To prevent further lock plunger malfunctioning, the following must be accomplished: (a) Replace lock plunger P/N 404-4088121-3 with new lock plunger P/N 404- 4900121-5 on each main landing gear by July 31, 1960. (b) At each 320 hours' time in service commencing not later than May 15, 1960, visually inspect main and nose gear lock plungers for a spalling or flaring condition. Check the lock plunger for free operation. The plunger should be free from dirt, dust, moisture, ice, etc. If spalling or flaring exists, the lock plunger must be chamfered (rounded out) at the corners of the plunger for the full length of the flat area. (Martin Service Bulletin No. 404-260 dated October 30, 1952, partially covers this subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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