AD 50-25-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Univair Aircraft Corporation | 108 | Airworthiness Directives; STINSON Model All Model 108 Series Aircraft |
| aircraft | Univair Aircraft Corporation | 108-1 | Airworthiness Directives; STINSON Model All Model 108 Series Aircraft |
| aircraft | Univair Aircraft Corporation | 108-2 | Airworthiness Directives; STINSON Model All Model 108 Series Aircraft |
| aircraft | Univair Aircraft Corporation | 108-3 | Airworthiness Directives; STINSON Model All Model 108 Series Aircraft |
Unsafe Condition
Fuel seepage into the space between the inner cabin trim and the outer fabric covering of the fuselage, resulting in soaking of insulating material in the cabin wall due to fuel spillage during filling, thermal expansion in full tanks, or tank leakage.
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Required Actions
Install a drip strip similar to that shown in Figure 1 on the underside of each wing to prevent fuel from flowing from the wing to the fuselage.
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Compliance Time
not later than September 1, 1950
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Affected Aircraft
Univair Aircraft Corporation Model 108, 108-1, 108-2, 108-3 aircraft
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Federal Register Abstract
Fuel drip strip
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_50-25-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 50-25-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; STINSON Model All Model 108 Series Aircraft Subject: Fuel drip strip Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Univair Aircraft Corporation Model: 108 | 108-1 | 108-2 | 108-3 Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 50-25-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 50-25-01 SUBJECT HEADING: Airworthiness Directives; STINSON Model All Model 108 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 50-25-01 STINSON: Applies to All Model 108 Series Aircraft. Compliance required not later than September 1, 1950. Reports have been received of fuel seepage into the space between the inner cabin trim and the outer fabric covering of the fuselage. This results in soaking of insulating material in the cabin wall. The source of the fuel can be spillage during filling of tanks, thermal expansion of fuel in full tanks, or tank leakage. This fuel runs to the under surface of the wing, adhering to the lower curved surface of the trailing edge of the wing at the flap well, thence inboard to the fuselage and across the rear window. Since the window seal is often not perfectly tight the fuel may then enter the cabin wall. To preclude the fire hazard of fuel soaked insulation within the cabin wall due to these causes, a drip strip similar to that shown in Figure 1 should be installed on the underside of each wing. This drip strip will prevent fuel from flowing from the wing to the fuselage. (Piper Service Bulletin No. 115, dated March 31, 1950, covers this same subject.) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_50-25-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 50-25-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; STINSON Model All Model 108 Series Aircraft Subject: Fuel drip strip Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Univair Aircraft Corporation Model: 108 | 108-1 | 108-2 | 108-3 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: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 50-25-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 50-25-01 SUBJECT HEADING: Airworthiness Directives; STINSON Model All Model 108 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 50-25-01 STINSON: Applies to All Model 108 Series Aircraft. Compliance required not later than September 1, 1950. Reports have been received of fuel seepage into the space between the inner cabin trim and the outer fabric covering of the fuselage. This results in soaking of insulating material in the cabin wall. The source of the fuel can be spillage during filling of tanks, thermal expansion of fuel in full tanks, or tank leakage. This fuel runs to the under surface of the wing, adhering to the lower curved surface of the trailing edge of the wing at the flap well, thence inboard to the fuselage and across the rear window. Since the window seal is often not perfectly tight the fuel may then enter the cabin wall. To preclude the fire hazard of fuel soaked insulation within the cabin wall due to these causes, a drip strip similar to that shown in Figure 1 should be installed on the underside of each wing. This drip strip will prevent fuel from flowing from the wing to the fuselage. (Piper Service Bulletin No. 115, dated March 31, 1950, covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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