ANCHORAGE, AK, USA
N793C
Stinson 108
A commercial pilot departed a private lake in a float equipped airplane for a flight over a 12 mile wide area of water. He intended to pick up two friends staying at a cabin, whom he dropped off the day before. The airplane did not arrive at the lake, and was reported overdue. Six days later, the body of the pilot was found along the shore of the area of water the pilot intended to cross. He was wearing a flotation cushion that was carried in the airplane. The cause of death was hypothermia, and drowning. The airplane has not been found. For several months before the accident, the airplane had a recurring engine roughness, backfiring, and several engine fires during start-up. During an annual inspection, one month before the accident, a mechanic installed a six point engine primer system. During flights within two days of the accident, passengers who flew in the airplane, commented that the engine would backfire when the throttle was reduced. One day before the accident, prior to flying the two friends to the cabin, the pilot purchased 20 gallons of automotive fuel, and poured it into the right wing fuel tank. During taxi for departure, the engine quit, and the pilot had difficulty restarting the engine. Automotive fuel is not recommended, or approved, for the engine.
HISTORY OF FLIGHT On May 24, 1999, at an estimated time of 0645 Alaska daylight time, a float equipped Stinson 108 airplane, N793C, is presumed to have crashed into the water, about 8 miles southwest of Anchorage, Alaska. The airplane was reported overdue, and has not been located. The airplane was being operated as a visual flight rules (VFR) local area personal flight when the accident occurred. The airplane was registered to, and operated by, the pilot. The commercial certificated pilot, the sole occupant, received fatal injuries. He was located on May 30, 1999. Visual meteorological conditions prevailed in the area of the accident. A VFR flight plan was not filed. The flight originated from Campbell Lake, a private lake located on the south side of Anchorage, about 0630 on May 24, 1999. On May 23, 1999, the pilot flew two friends to a National Park Service cabin, located on the shore of Vogel Lake. The lake is located on the Kenai Peninsula, about 16 miles southwest of Anchorage. The pilot planned to return the following morning to pick up his passengers for a return flight to Anchorage. The route of flight from Campbell Lake to Vogel Lake is southbound, across the Turnagain Arm of the Cook Inlet. The distance over open water, from the south shore of Campbell Lake, to the north shore of the Kenai Peninsula, is about 12 miles. On May 24, 1999, about 0630, the accident airplane departed Campbell Lake, but failed to arrive at Vogel Lake. The pilot's office manager reported the airplane overdue at 1442, when the pilot failed to arrive at his office. An on-demand air taxi operator picked up the passengers at Vogel Lake about 1600. The air taxi pilot had been flying in the Turnagain Arm area about 0900. At that time, he said the wind was blowing from the southeast about 15 knots, and breaking waves with white caps were visible on the water. The accident occurred during the hours of daylight at an estimated location of latitude 61 degrees, 04.5 minutes north, and longitude 150 degrees, 11.25 minutes west. CREW INFORMATION The pilot held a commercial pilot certificate with airplane single-engine land, multiengine land, single-engine sea, and instrument airplane ratings. He held private pilot privileges with a glider rating. In addition, the pilot held a flight instructor certificate with airplane single-engine, and multiengine ratings. The most recent second-class medical certificate was issued to the pilot on April 17, 1999, and contained no limitations. No personal flight records were located for the pilot and the aeronautical experience listed on page 3 of this report was obtained from a review of the airmen Federal Aviation Administration (FAA) records on file in the Airman and Medical Records Center located in Oklahoma City. On the pilot's application for medical certificate, dated April 17, 1999, the pilot indicated that his total aeronautical experience consisted of 2,800 hours, of which 40 were accrued in the previous 6 months. AIRCRAFT INFORMATION Examination of the maintenance records revealed the most recent annual inspection of the engine and airframe was on May 5, 1999. At that time, the airframe had accrued 1,480.1 hours total time. The engine had accrued 885.7 hours since a major overhaul, completed on April 21, 1977. A McCauley propeller, model 2A34C203-C, was installed on August 3, 1998, under Supplemental Type Certificate (STC) number SA388NW. The propeller accrued 4 hours before the last annual inspection. A Teledyne Continental Motors, O-470-L engine, was installed the airplane on March 22, 1984, under STC number SA1199WE, as a replacement for the original engine. A review of the mechanic's discrepancy log sheet, utilized during the most recent annual inspection, revealed 28 airworthiness problems listed for repair. The number five discrepancy indicated "engine catches fire during starting." The repair for that problem was, "Repaired leaking exhaust, and install 6 point primer system." The number seven discrepancy was, "Fuel primer leaks". The primer was replaced. A friend of the pilot reported the right fuel tank was fueled on May 23, 1999, with 20 gallons of automotive fuel. Teledyne Continental Motors does not recommend the use of automotive fuel. No STC was found authorizing the use of automotive fuel in the accident airplane. METEOROLOGICAL INFORMATION The closest official weather observation station is Anchorage, which is located about 8 nautical miles northeast of the presumed accident site. On May 24, 1999, at 0653, an Aviation Routine Weather Report (METAR) was reporting in part: Wind, 136 degrees (magnetic) at 11 knots; visibility, 10 statute miles; clouds, few at 3,500 feet, 8,000 feet broken, 20,000 feet broken; temperature, 48 degrees F; dew point, 35 degrees F; altimeter, 29.51 inHg. COMMUNICATIONS No record of radio communication between the pilot and any FAA facility was located. If aircraft remain below 600 feet msl, a departure to the south from Campbell Lake does not require communication with the FAA. No record of a radar track was located. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the pilot was conducted under the authority of the Alaska State Medical Examiner, 5700 E. Tudor, Anchorage, Alaska, on June 1, 1999. The cause of death for the pilot was attributed to hypothermia and drowning. A toxicological examination was conducted by the Federal Aviation Administration (FAA) Civil Aeromedical Institute (CAMI) on June 14, 1999. The examination revealed the presence of cimetidine in the blood and urine. According to the Physician Desk Reference, cimetidine is the generic name for Tagamet, a medicine used to inhibit gastric acid secretion. SURVIVAL ASPECTS Search personnel reported that survival time, in water less than 40 degrees F, is typically less than one hour. The pilot, when found, had a float type cushion strapped to his back. It was secured around his chest by his pant belt, threaded through the handles of the cushion. SEARCH AND RESCUE Search personnel reported they conducted an extensive search along the pilot's anticipated route of flight over Turnagain Arm. The body of the pilot was located on May 30, 1999, in the waters of Chickaloon Bay, along the north shore of the Kenai Peninsula, about 15 miles south of Anchorage. No portion of the airplane has been found. ADDITIONAL INFORMATION Following the accident, one of the two friends dropped at Vogel Lake on May 23, 1999, reported he and the pilot flew to Vogel Lake with two other passengers (total of four persons) on Saturday, May 22, 1999. Before departure, the pilot inquired about each passenger's weight, and said "we're a little over-weight, but that's O.K." He provided a short briefing to the passengers about the location of the emergency locator transmitter (ELT), and the location of cushions that could provide flotation. The pilot departed from Campbell Lake down wind, and remained about 1,000 feet msl over the waters of Turnagain Arm. The pilot did not utilize the airplane radio. After landing on Vogel Lake, the airplane's engine backfired several times when power was reduced to idle. One passenger commented that the engine "sounded like my dad's old tractor." The second of the two friends dropped at Vogel Lake, reported he accompanied the pilot to an automotive service station before the flight on Sunday, May 23, 1999. The pilot utilized four, five gallon plastic gas cans that were sitting next to the pilot's dock. The gas cans had spouts attached to the cans, but the spouts were not capped. He said the pilot poured some liquid residue out of some of the containers before filling them at the service station. Upon returning to the airplane, the 20 gallons of fuel was poured into the right wing fuel tank. The pilot commented that the left fuel tank was full. The pilot then pumped water from the airplane's float compartments. He provided a short briefing about the location of the ELT, flotation cushions, and emergency escape procedures should the airplane capsize on the water. After the two friends boarded the airplane, the pilot started the engine and taxied out onto the lake. The engine suddenly quit running, and the pilot had some difficulty restarting the engine. The pilot commented "this has not happened before." Once the engine restarted, the pilot departed and flew about 900 feet msl over the Turnagain Arm. The pilot did not utilize the airplane radio. During the approach to Vogel Lake, the engine backfired several times as the throttle was reduced. After off-loading the passenger's gear, the pilot started up the engine without any noticeable problem, and departed for Anchorage. Following the accident, two certificated mechanics reported they were working on an airplane at Campbell Lake over the weekend before the accident flight. They observed, and heard the accident airplane while it was being operated around the lake. Both mechanics said the engine was running rough, producing popping sounds and backfiring, while the airplane was on the water and while airborne. An FAA airworthiness inspector, Anchorage Flight Standards District Office (FSDO) conducted several telephone interviews with witnesses who live around Campbell Lake. He was told the accident airplane's engine had been running rough, backfiring, and popping for several months before the accident. The inspector visited the automotive service station where the pilot purchased the fuel for the airplane. The outside of the gasoline pump contained the following warning: "The gasoline dispensed from this pump is oxygenated and will reduce carbon monoxide pollution from motor vehicles. The gasoline is oxygenated with ethanol and contains no more than 10 percent ethanol by volume. Its oxygen content is not less than 2.0 percent by weight. Warning: The Federal Aviation Administration prohibits the use of this fuel in aircraft."
Undetermined.
Source: NTSB Aviation Accident Database
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