AD 51-11-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Martin-Marietta Corporation | 202 | Martin Models 202 and 202A Airplanes |
| aircraft | Martin-Marietta Corporation | 202A | Martin Models 202 and 202A Airplanes |
Unsafe Condition
Modification Board Items
Required Actions
Decrease breaker rating for propeller anti-icing circuit to 5 amperes to accommodate No. 20 wire (Model 202 only). Install negative pressure scoop on battery vent line. Add manually operated charging valve in the emergency brake hydraulic system per Service Bulletin No. 185. Provide circuit protection for voltmeter, generator tip light circuit at main bus, and ammeter wires. Install circuit breaker in circuit breaker panel with wire routed back to auxiliary bus control relay.
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Compliance Time
Compliance required by August 16, 1951; November 16, 1951; December 1, 1951; and February 1, 1952 respectively.
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Affected Aircraft
Martin-Marietta Corporation Models 202 and 202A airplanes except as noted.
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Federal Register Abstract
Modification Board Items
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_51-11-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 51-11-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Martin Models 202 and 202A Airplanes Subject: Modification Board Items Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Martin-Marietta Corporation Model: 202 | 202A Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 51-11-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 51-11-01 SUBJECT HEADING: Martin Models 202 and 202A Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 51-11-01 MARTIN: Applies to All Models 202 and 202A Airplanes Except as Noted. Compliance required as specified herein. Compliance with this note cancels the requirements of AD 50-41-02. In order to comply with the recommendations of the Martin 202 Modification Board, the following items must be accomplished. In all cases, modifications which are demonstrated to provide a level of safety equivalent to that provided by the modifications listed herein will be acceptable in lieu of the listed modifications. Compliance required by August 16, 1951. 1. Decrease breaker rating for propeller anti-icing circuit to 5 amperes to accommodate No. 20 wire. (Applies to Model 202 airplanes only.) 2. Install negative pressure scoop on battery vent line. Compliance require by November 16, 1951. 1. Add manually operated charging valve in the emergency brake hydraulic system in accordance with Glenn L. Martin Co. Service Bulletin No. 185. Compliance required by December 1, 1951. 1. Provide circuit protection for voltmeter. 2. Provide circuit protection at main bus for generator tip light circuit. 3. Provide circuit protection for ammeter wires. Compliance required by February 1, 1952. 1. Install circuit breaker in circuit breaker panel with wire routed back to auxiliary bus control relay. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_51-11-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 51-11-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Martin Models 202 and 202A Airplanes Subject: Modification Board Items Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Martin-Marietta Corporation Model: 202 | 202A 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: 51-11-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 51-11-01 SUBJECT HEADING: Martin Models 202 and 202A Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 51-11-01 MARTIN: Applies to All Models 202 and 202A Airplanes Except as Noted. Compliance required as specified herein. Compliance with this note cancels the requirements of AD 50-41-02. In order to comply with the recommendations of the Martin 202 Modification Board, the following items must be accomplished. In all cases, modifications which are demonstrated to provide a level of safety equivalent to that provided by the modifications listed herein will be acceptable in lieu of the listed modifications. Compliance required by August 16, 1951. 1. Decrease breaker rating for propeller anti-icing circuit to 5 amperes to accommodate No. 20 wire. (Applies to Model 202 airplanes only.) 2. Install negative pressure scoop on battery vent line. Compliance require by November 16, 1951. 1. Add manually operated charging valve in the emergency brake hydraulic system in accordance with Glenn L. Martin Co. Service Bulletin No. 185. Compliance required by December 1, 1951. 1. Provide circuit protection for voltmeter. 2. Provide circuit protection at main bus for generator tip light circuit. 3. Provide circuit protection for ammeter wires. Compliance required by February 1, 1952. 1. Install circuit breaker in circuit breaker panel with wire routed back to auxiliary bus control relay. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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