On June 12, 1998, about 1500 Alaska daylight time, a tundra tire equipped Aeronca 15AC airplane, N1023H, sustained substantial damage during a forced landing about 10 miles east of Homer, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) local area personal flight when the accident occurred. The certificated commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on June 22, 1998, at 1335, the pilot reported he was departing to the south from a remote area located near the Grewingk Glacier, in the Kachemak Bay, Alaska State Park. The departure area was oriented north/south, and was about 800 feet long. The pilot reported the right fuel tank contained nine gallons of fuel, the left fuel tank contained 6 gallons, and the right fuel tank was selected. The pilot said the airplane does not have a fuel selector position for "Both" fuel tanks. The airplane does not have a header tank installed in the fuel system. The pilot indicated a crosswind was blowing from the west about 15 knots, and that during the initial climb, a gust of wind "pushed the airplane sideways." He said the sideways motion sloshed fuel away from the right fuel tank line, and the engine quit about 150 feet above the ground. He reported he switched the fuel selector to the left fuel tank, but the engine did not restart. The pilot made an emergency landing in an area of large boulders. The main landing gear was sheared off. The airplane received damage to the left wing strut and fuselage. The airplane was equipped with two 18 gallon, wing mounted fuel tanks, installed under a supplemental type certificate (STC). Each tank has a fuel line attach point located at the lower, inboard edge of each tank. The tanks do not contain any internal baffles. The tank fuel lines are routed to a fuel tank selector valve. The airplane's original fuel selector valve was an "ON/OFF" valve, and selection of a particular tank was not possible. The accident airplane's fuel valve has three positions; "LEFT", "RIGHT", and "OFF." It was installed on October 12, 1994, by a certificated airplane mechanic, and approved by a Federal Aviation Administration (FAA) airworthiness inspector on October 14, 1994. The fuel valve installation was accomplished to replace a three-way valve that was not approved for use in aircraft. The nonapproved valve was installed in the airplane prior to the pilot purchasing the airplane.