AD 59-12-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Maryland Air Industries, Inc. | F-27 | Airworthiness Directives; Fairchild All Model F-27 Series Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27A | Airworthiness Directives; Fairchild All Model F-27 Series Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27B | Airworthiness Directives; Fairchild All Model F-27 Series Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27F | Airworthiness Directives; Fairchild All Model F-27 Series Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27G | Airworthiness Directives; Fairchild All Model F-27 Series Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27J | Airworthiness Directives; Fairchild All Model F-27 Series Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27M | Airworthiness Directives; Fairchild All Model F-27 Series Aircraft |
Unsafe Condition
A loose 'B' nut on the fuel line connection to the combustion heater fuel control unit caused fuel leakage around the shroud.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove and retain shroud assemblies P/N 27-774575-1 attached to specified tube assemblies. Inspect and torque fittings to specified values (135-150 in-lbs for P/N 27-774512-11 and 40-65 in-lbs for P/N 27-683051-151/-251). Reinstall shrouds after verifying no fuel leakage during heater operation.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
July 15, 1959, and every 100 hours thereafter until the permanent fix is incorporated.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Fairchild F-27 Series aircraft equipped with the heater system, including models F-27, F-27A, F-27B, F-27F, F-27G, F-27J, F-27M.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Combustion Heater Inspection
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_59-12-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-12-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Fairchild All Model F-27 Series Aircraft Subject: Combustion Heater Inspection Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Maryland Air Industries, Inc. Model: F-27 | F-27A | F-27B | F-27F | F-27G | F-27J | F-27M 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: 59-12-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-12-01 SUBJECT HEADING: Airworthiness Directives; Fairchild All Model F-27 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-12-01 FAIRCHILD: Applies to all F-27 Series aircraft equipped with the heater system. Compliance required by July 15, 1959, and every 100 hours thereafter until forthcoming permanent fix is incorporated. (1) An incident has been reported in which a loose "B" nut on the fuel line connection to the combustion heater fuel control unit caused fuel to leak out around the shroud. In order to preclude possibilities of leakage at the heater fuel system fittings, remove and retain shroud assemblies, P/N 27-774575-1, attached to tube assemblies, P/N's 27-683051-151 or -251 and 27-774512-11, connected to fuel control assembly, P/N 43C80. Also remove and retain shroud assembly, P/N 27-774575-1, attached to opposite end of tube assembly, P/N 27-774512-11, connected to heater assembly, P/N 49C65. (2) At locations where shrouds were removed, inspect and determine that fittings of tube assemblies are torqued to proper values and no evidence of fuel leakage exists. Torque fittings of tube assembly, P/N 27-774512-11 to 135 in. lbs. min. - 150 in. lbs. max., and tube assembly P/N 27-683051-151 or -251 to 40 in. lbs. min. - 65 in. lbs. max. (3) Operate heater to determine that no evidence of fuel leakage exists at tube assembly connections to fuel control and heater assemblies and reinstall shroud assemblies. (Fairchild F-27 Service Bulletin No. 21-48 dated April 22, 1959, covers this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_59-12-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-12-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Fairchild All Model F-27 Series Aircraft Subject: Combustion Heater Inspection Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Maryland Air Industries, Inc. Model: F-27 | F-27A | F-27B | F-27F | F-27G | F-27J | F-27M 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: 59-12-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-12-01 SUBJECT HEADING: Airworthiness Directives; Fairchild All Model F-27 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-12-01 FAIRCHILD: Applies to all F-27 Series aircraft equipped with the heater system. Compliance required by July 15, 1959, and every 100 hours thereafter until forthcoming permanent fix is incorporated. (1) An incident has been reported in which a loose "B" nut on the fuel line connection to the combustion heater fuel control unit caused fuel to leak out around the shroud. In order to preclude possibilities of leakage at the heater fuel system fittings, remove and retain shroud assemblies, P/N 27-774575-1, attached to tube assemblies, P/N's 27-683051-151 or -251 and 27-774512-11, connected to fuel control assembly, P/N 43C80. Also remove and retain shroud assembly, P/N 27-774575-1, attached to opposite end of tube assembly, P/N 27-774512-11, connected to heater assembly, P/N 49C65. (2) At locations where shrouds were removed, inspect and determine that fittings of tube assemblies are torqued to proper values and no evidence of fuel leakage exists. Torque fittings of tube assembly, P/N 27-774512-11 to 135 in. lbs. min. - 150 in. lbs. max., and tube assembly P/N 27-683051-151 or -251 to 40 in. lbs. min. - 65 in. lbs. max. (3) Operate heater to determine that no evidence of fuel leakage exists at tube assembly connections to fuel control and heater assemblies and reinstall shroud assemblies. (Fairchild F-27 Service Bulletin No. 21-48 dated April 22, 1959, covers this same subject.) 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.
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