68-20-05: Fuel Tank Inspection

68-20-05 AERONCA: Amendment 39-662. Applies to Models 15AC and S15AC, S/N's 15AC-1 and up. To be accomplished within 25 hours in service after the effective date of this AD and thereafter at intervals not to exceed 50 hours time in service from the last inspection. As a result of a number of forced landings due to fuel exhaustion caused by a collapsed fuel tank or siphoning of fuel, accomplish the following: (a) Determine that the wing fuel cells are lying flat and follow the contour of the wing cavity. (b) Inspect fuel cell filler caps for security and identification. Aeronca unvented spring loaded cap, P/N 1-3738 or FAA approved equivalent must be installed. A drawing of P/N 1-3738 is available from Aeronca, Inc., Middletown, Ohio 45042. (c) Determine that vent lines are open to both tanks by removing vent lines at tanks and blowing air through the lines. (d) Determine that the small auxiliary vent holes are located at the same height above the wing upper surface. (e) Determine that the vent line is securely clamped and the vent line hose connection has not deteriorated. (f) Determine that angular cut-off at the termination of the main vent line faces forward. The inspection required by this AD constitutes preventive maintenance and may be accomplished by persons so authorized under FAR 43.3. Aircraft log record entry must be made to reflect AD compliance in accordance with FAR 43.9. This amendment is effective October 3, 1968.