SEA07LA209

After terminating his aerial photography flight early because of problems with the camera system, the pilot experienced a sudden total loss of engine power after retarding the throttle on downwind. Because the engine did not restart after he switched tanks, the pilot turned base early in an attempt to make it to the runway. During the pilot's attempt to reach the runway, the aircraft descended to an altitude where it contacted a standard rural power transmission line, and then shortly thereafter impacted the terrain off the approach end of the runway. After the aircraft came to a stop, a fire started, which eventually consumed a considerable portion of the airframe. The reason for the loss of power was unable to be determined.

On July 22, 2007, approximately 1650 mountain daylight time, a Cessna TU206F, N2089U, impacted a set of power lines during an attempted power-off forced landing at Nampa Municipal Airport, Nampa, Idaho. The airline transport pilot received minor injuries, his camera operator received serious injuries, and the aircraft, which is owned and operated by Remote Airborne Mapping Services, was destroyed by the post-crash fire. The 14 CFR Part 91 aerial mapping flight, departed Nampa Airport about three hours and twenty minutes prior to the accident. No flight plan had been filed. There was no report of an ELT activation.

According to the pilot, just after he rolled out on the downwind leg for a full-stop landing, the engine suddenly quit. Reportedly, the engine did not run rough or give any other indication of an impending problem, and because the engine stopped running while at a reduced power setting, the pilot did not at first realize what had happened. Once he realized what had happened, the pilot switched tanks, but when that did not help, he turned base early in an attempt to maneuver the aircraft to a forced landing on the active runway. During the no-power forced landing attempt, the aircraft descended to an altitude where it could not clear a set of power lines off the end of the runway. After hitting the power lines, the aircraft impacted the terrain, and soon thereafter burst into flames. Almost the entire airframe structure was destroyed by the fire.

In a post-accident interview, the pilot said that he was flying one of a series of aerial photography flights, all of which took place at 8,500 mean sea level (MSL). He said that all the flights followed a standard profile, and that they all lasted between three and one-half and four hours, and that he made sure that he was always on the ground by the four hour mark. On this particular flight, he had terminated the mission earlier than normal because there was a problem with the high-voltage system that operated the camera. He stated that on all the flights he used his wristwatch for tracking the total time of the flight, and he used a stopwatch to make sure that he switched between tanks every thirty minutes. Based on his timing, he estimated that he had between eight to ten gallons of fuel remaining when he rolled out on downwind.

An inspection of the engine and the remains of the airframe did not reveal any clear indication as to what sequence of events lead to the loss of power on downwind.