HISTORY OF FLIGHT On July 18, 1993, at approximately 1730 Alaska daylight time, a tundra tire equipped Piper PA18 airplane, N1009A, crashed while maneuvering at low altitude near Chickaloon Creek, 20 miles southeast of the Anchorage airport. The private pilot and a passenger had departed Campbell Airstrip, Anchorage, Alaska, at approximately 1700 on a VFR flight for personal reasons. The flight was conducted in visual meteorological conditions under 14 CFR Part 91. No flight plan was filed. The pilot and passenger received serious injuries and the aircraft was destroyed by post- crash fire. At 1715, a local airman, who had just landed at his private airstrip near Chickaloon Creek, heard and saw the accident airplane approach at low altitude. He observed the airplane to make a low pass at a landing area which was marked with "closed" signs. The witness then heard a "distinct wump" and then silence. He said that he then ran to the crash site, arriving at approximately 1730. At approximately 1745, an Alaska Air National Guard (ANG) H60 helicopter crew, while on a routine training flight, sighted the fire from the accident airplane. INTERVIEW WITH PASSENGER On July 19, 1993, the NTSB interviewed Robert J. Lukacinsky in the burn unit of the Providence Hospital, Anchorage, Alaska. He said that he had been given morphine for pain but consented to an interview. He said that the aircraft had been maneuvering at low altitude, "maybe 100 feet" and that he could look down and see fish (salmon) in the creek. Recalling a turn to the right, he said that he felt "a little wind or something" and "we went over and straight down." (See interview summary with Mr. Lukacinsky.) The passenger could not comment on the specifics of the weather, but said that visibility was good at the time, and other than the sensation of "a little wind or something" at the time of the upset, weather conditions could not be recalled. CRASH KINEMATICS AND WRECKAGE AND IMPACT INFORMATION The NTSB examined still and video photographs of the crash scene, including those which were taken during rescue and the aircraft fire. Wing damage is consistent with the passenger's recollection that the aircraft "went straight down." The wing tip surfaces did not reveal impact damage. Damage is more or less uniform along the leading edge, revealing a flattening of the sheet metal under the fabric at nearly right angles to the wing chord. The wings came to rest on the trailing edges with the leading edges pointing vertically. Ailerons were approximately neutral. The cockpit, fuselage and center wing sections were destroyed by fire. The aircraft reportedly had 30 inch AIRSTREAK tundra tires which were destroyed in the fire. The propeller was snapped off at the hub and could be seen approximately 20 yards from the wreckage. The loss of the propeller at impact was consistent with the witness's statement that the engine sounded normal until impact. METEOROLOGICAL INFORMATION Photographs taken by a witness to the accident showed smoke to be rising nearly vertical to an undetermined altitude feet before changing direction to the southwest. The photographs showed a cloud base truncating local mountains at an undetermined elevation with visual meteorological conditions prevailing. No precipitation could be seen in the photographs. ADDITIONAL INFORMATION Due to extensive injuries and slow recuperation in a Seattle hospital, the pilot has been unable to provide information or the NTSB 6120.1/2 Pilot Report on this accident. The NTSB has been unable to learn more about the aircraft, its maintenance history, modifications, trim or rigging, or supplemental type certificates. It is unknown whether or not automobile gas or AVGAS was in the aircraft at the time, or the specific size or STC regarding the "tundra tires." The FAA Certification Office in Anchorage, Alaska, reported that there are no approvals on file, in either design or quality control for 30 inch Airstreak tires.