This July 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Glastar SH-4. Injuries: 3 Fatal. Location: Kenai, Alaska. Aircraft damage: Destroyed.
What reportedly happened: The airplane was built by the pilot from a kit, and was designed by the kit manufacturer to have two side-by-side seats in the cockpit. A large cargo area was behind the two front seats. According to a neighbor, the accident airplane was equipped with a third seat, designed and built by the pilot. The third seat was installed in the cargo area and was designed to fold up for use, and was equipped with a seat belt. The kit manufacturer indicated that several builders have designed and built a third seat in the cargo compartment area of their airplanes. These seats had been individually designed, as there were no after-market or third-party suppliers of rear seats for the airplane.
The pilot and two passengers departed on a local flight in the amphibious, float-equipped experimental airplane. About 40 minutes after takeoff, the burning wreckage of the airplane was spotted by overflying aircraft. No maintenance records or construction build records were located for the airplane. No weight and balance data for the airplane was located. According to the manufacturer, the airplane’s gross weight was 2,100 pounds if equipped with floats. A calculation of the airplane’s estimated weight done by the NTSB’s Investigator-In-Charge came to an estimated 2,110 pounds without any fuel, which indicated that the airplane was over-gross at the time of the accident. The airplane appeared to have hit the ground in a left-wing- and nose-low attitude, an indication of an aerodynamic stall.
Probable cause: The pilot’s failure to maintain adequate airspeed during maneuvering flight, which resulted in an aerodynamic stall and uncontrolled descent to the ground. Contributing to the accident was the airplane’s over-gross weight condition.
For more information: NTSB.gov