AD 49-15-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Textron Aviation Inc. | Army AT-11 | Airworthiness Directives; Beech Model C18S and AT-11 Airplanes |
| aircraft | Textron Aviation Inc. | C18S | Airworthiness Directives; Beech Model C18S and AT-11 Airplanes |
Unsafe Condition
Fuel or vapors discharged from fuel tank vents entering the tail wheel well may cause fuel fumes to collect in hazardous concentrations in the cockpit and cabin.
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Required Actions
Install a placard adjacent to the fuel tank selector valve with specified text if equipped with a nose fuel tank. Extend rear fuel tank vents 7 inches below the wing skin with scarfed ends, or relocate vent outlets 27 inches outboard, or install a fumeproof panel over fuselage bulkhead No. 12. Remove the vent system with outlet below the wing unless item 2 is complied with for airplanes with dual vent systems.
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Compliance Time
not later than next annual inspection
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Affected Aircraft
Beech Model C18S and AT-11 aircraft equipped with nose fuel tank or wing fuel tank vents discharging below the wings.
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Federal Register Abstract
Fuel Tank Vent System
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_49-15-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 49-15-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Beech Model C18S and AT-11 Airplanes Subject: Fuel Tank Vent System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Textron Aviation Inc. Model: Army AT-11 | C18S Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 49-15-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 49-15-03 SUBJECT HEADING: Airworthiness Directives; Beech Model C18S and AT-11 Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 49-15-03 BEECH: Applies to All Models C18S and AT-11 Aircraft Equipped With: (1) Nose Fuel Tank or (2) Wing Fuel Tank Vents Which Discharge Below the Wings. Compliance required not later than next annual inspection. As a result of fuel or vapors discharged from fuel tank vents entering the tail wheel well, fuel fumes in hazardous concentrations may collect in the airplane's cockpit and cabin. To preclude this condition, the following must be accomplished: (1) If the airplane is equipped with a nose fuel tank, install adjacent to the fuel tank selector valve a suitable placard which reads "Use Nose Tank for Warm Up -Take-Off on Main Tanks -At Safe Altitude Use Nose Tank." (2) On airplanes with wing tank vents extending below the wing, accomplish either 2(a) or 2(b) or 2(c). (a) Using an adequate tube splice, extend the rear fuel tank vents to a distance of 7 inches below the wing skin. The ends of these vents are to be scarfed at 45 degrees with the scarfed surface facing aft. (b) Relocate the outlet end of each rear tank vent to a point approximately 27 inches outboard of its present position. (c) Install a suitably designed fabric or equivalent fumeproof panel over the opening of fuselage bulkhead No. 12 to act as a draft barrier. (3) If the wing fuel tanks are equipped with two vent systems (one system having the vent outlet below the wing and the other, above) the system with the vent outlet below the wing should be removed from the rear tanks unless item 2 is complied with. (Beech Service Bulletin No. C18-10 dated January 31, 1949 covers this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_49-15-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 49-15-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Beech Model C18S and AT-11 Airplanes Subject: Fuel Tank Vent System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Textron Aviation Inc. Model: Army AT-11 | C18S Product Type: Aircraft Product Subtype: Small 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: 49-15-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 49-15-03 SUBJECT HEADING: Airworthiness Directives; Beech Model C18S and AT-11 Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 49-15-03 BEECH: Applies to All Models C18S and AT-11 Aircraft Equipped With: (1) Nose Fuel Tank or (2) Wing Fuel Tank Vents Which Discharge Below the Wings. Compliance required not later than next annual inspection. As a result of fuel or vapors discharged from fuel tank vents entering the tail wheel well, fuel fumes in hazardous concentrations may collect in the airplane's cockpit and cabin. To preclude this condition, the following must be accomplished: (1) If the airplane is equipped with a nose fuel tank, install adjacent to the fuel tank selector valve a suitable placard which reads "Use Nose Tank for Warm Up -Take-Off on Main Tanks -At Safe Altitude Use Nose Tank." (2) On airplanes with wing tank vents extending below the wing, accomplish either 2(a) or 2(b) or 2(c). (a) Using an adequate tube splice, extend the rear fuel tank vents to a distance of 7 inches below the wing skin. The ends of these vents are to be scarfed at 45 degrees with the scarfed surface facing aft. (b) Relocate the outlet end of each rear tank vent to a point approximately 27 inches outboard of its present position. (c) Install a suitably designed fabric or equivalent fumeproof panel over the opening of fuselage bulkhead No. 12 to act as a draft barrier. (3) If the wing fuel tanks are equipped with two vent systems (one system having the vent outlet below the wing and the other, above) the system with the vent outlet below the wing should be removed from the rear tanks unless item 2 is complied with. (Beech Service Bulletin No. C18-10 dated January 31, 1949 covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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