SEA03FA124

The modified single-engine, turboprop airplane had a commercial-rated pilot/owner in the right front seat who was the pilot in command (PIC), a private pilot in the left front seat, and a student pilot in the rear seat. The purpose of the flight was to proceed to a nearby airport in order to refuel the aircraft prior to a longer flight back to its home base. According to the private pilot in the left seat, after the engine was started, the after-market, panel-mounted, fuel management system/fuel flow meter indicated a "Fuel Remaining" of 235 pounds, and at that same point in time, the left main fuel tank gauge was at the top of the yellow arc (approximately 15 gallons), and the right main fuel tank gauge needle was at the bottom of the yellow arc (approximately empty). There was no operating restriction indicating the aircraft could not be operated in that fuel configuration. Believing that there was adequate fuel for the flight, the PIC departed for what should have been a flight of ten minutes or less. After departure, a climbing right turn was made followed by the aircraft leveling off approximately 2,000 feet above the terrain, and soon thereafter the right fuel tank "Fuel Low" light came on. About one minute later the engine lost power. The PIC was not able to restart the engine, and therefore found it necessary to execute a forced landing in a wheat field located among hilly terrain. Because there were power lines at the approach end of the field, the PIC was not able to touch down until the aircraft was just past half-way down the field. Although the touchdown was successful, the PIC was unable to stop the aircraft before it exited the far end of the field and rolled/slid into a deep ravine. Subsequent inspections of the airframe, and an inspection/test run of the engine, revealed no system malfunctions. A post-accident review revealed that the aircraft's fuel system had been significantly modified during a major alteration that was never approved by the FAA. As part of the alteration, the route by which the excess fuel in the header tank was rerouted through the fuel system was significantly lengthened, and no approved flight tests had been performed to ensure that, after the alteration, adequate fuel would be supplied to the engine at all attitudes, power settings, fuel load totals, and fuel load distributions. It was also determined that, during the installation of the after-market fuel management system/fuel flow meter by an avionics shop, an incorrect calibration factor was entered in the unit, which would result in displaying an erroneous indication of the amount of fuel used by about 9 percent less than the actual amount. With an unaltered fuel system, the aircraft should have arrived at its destination with about 11 minutes of fuel remaining, and because there were no major alteration-related amendments made to the Pilot’s Operating Manual, the pilot had no way of knowing that the engine would lose power en route.

History of flight

On July 4, 2003, approximately 1330 Pacific daylight time, a turbine-powered Beech A36TC, N279WP, impacted the terrain during a power-out forced landing in a wheat field about three miles northwest of Pangborn Memorial Airport, Wenatchee, Washington. The commercial pilot/owner in the right seat, who was acting as pilot-in-command of this flight, received fatal injuries, the private pilot in the left seat, who was flying the aircraft at the time of the power loss, received serious injuries, and a student pilot passenger in a back seat received minor injuries. The aircraft, which was owned and operated by the pilot-in-command, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Dryden Airport, Cashmere, Washington, about 5 minutes earlier, was being operated in visual meteorological conditions. No flight plan had been filed. There was no report of an ELT activation.

According to the two surviving occupants, the purpose of the flight to Pangborn Airport in Wenatchee was to refuel the aircraft prior to heading back to their home on Vashon Island, which is located in the Puget Sound near Seattle, Washington. Prior to departing Cashmere, the pilot-in-command of the upcoming flight performed a preflight inspection of the aircraft. Neither of the other two occupants remembered seeing the pilot-in-command drain fuel from the fuel system sumps, but they did not feel it was factually accurate to say that he did not. After completion of the preflight inspection, the pilot-in-command boarded the aircraft, and the engine was started in preparation for taxi. According to the pilot in the left seat, after the engine was started, the panel-mounted Shadin Miniflo fuel management system indicated a "Fuel Remaining" of 235 pounds, and at that same point in time, the left main fuel tank gauge was at the top of the yellow arc (approximately 15 gallons), and the right main fuel tank gauge needle was at the bottom of the yellow arc (approximately empty). The aircraft was then taxied to the end of the runway, and the private pilot in the left seat made the takeoff using runway 25. After takeoff, he executed a right climbing turn, and then headed toward the northern end of the town of Wenatchee. He then leveled off in smooth air about 2,000 MSL (Mean Sea Level), and established a cruise speed of about 130 knots. Sometime during the first two minutes after level-off, the right main tank "Fuel Low" light came on and stayed illuminated. Within one minute of the illumination of the Fuel Low light, the engine lost power and began to spool down. Soon after the engine started to lose power, the pilot-in-command activated the fuel pump switches and moved the engine start switch to the down position (starter motor and igniter activation). He also rocked the wings in what the other occupants thought was an attempt to free up any fuel possibly trapped in the fuel tanks. The restart attempt was not successful, and the engine continued to spool down at a rate that was slower and smoother than what would be experienced during a ground shutdown. Approximately 10 seconds after the first indication of a loss of power the propeller came to a full stop, and within 25 seconds it appeared to be in a fully feathered position. At that point the throw-over yoke was moved from the pilot in the left seat to the pilot-in-command in the right seat, so that he could take control of the aircraft for the anticipated power-off forced landing. Initially the pilot-in-command headed for Fancher Field, a previously active airfield that is now closed, but because the aircraft was not going to be able to glide that far, he made the decision to put the aircraft down on the northwest-to-southeast axis of a wheat field located about one mile northeast of the airstrip (see satellite photograph #1). As he neared the field at an airspeed of approximately 110 knots, the pilot-in-command saw that there were power lines just off the northern (approach) end of the field, so he would be unable to touch down near the edge of the field, and instead had to clear the wires prior to descending to a touchdown point. According to the other two occupants, after crossing the wires and descending to the ground, the pilot essentially flew the aircraft onto the terrain without any significant glide or float. According to the pilot in the left seat, at the point of touchdown, the airspeed was approximately 100 knots. After the touchdown, the occupants felt a deceleration rate that indicated to them that significant braking was taking place, but, as the aircraft reached the southeast end of the field, it exited the wheat, crossed about 150 feet of grassy terrain, and then slid over the edge of a steep-sided narrow ravine. After crossing the northern edge of the ravine, the aircraft became momentarily "airborne," and then descended to a point of impact near the bottom of the ravine's southern wall.

According to the back seat occupant, who had been sitting in one of the front seats during the previous flight, he recalled that the Miniflo had indicated between 240 and 250 pounds of fuel remaining while the aircraft had been in the pattern for its last landing, and the fuel tanks gauges were at or near the aforementioned indications during the approach for landing. According to this occupant, at some time during the approach for the previous landing, the pilot-in-command stated that in the past, with the fuel gauges in that same configuration, and the Shadin indicating between 240 and 250 pounds, he had flown for an additional hour. This occupant further stated that although his memory was fuzzy, he thought he had seen the right main fuel tank "Fuel Low" light blink during the descent for landing, but it did not stay on.

Wreckage and impact information

The aircraft initially touched down just over half way through the approximately 2,100 foot long wheat field, and then rolled/slid about 1,200 feet before going off the edge of the ravine. The ravine itself was about 50 feet deep, and had walls inclined at an angle of about 40 degrees. The aircraft came to rest upright on an easterly heading, with the tip of the left wing sitting at the very bottom of the ravine, and the right wing pointing uphill along the southern wall. Except for the most outboard section of both wings (containing the internal tip tanks), the entire wreckage was intact at this one location. The right wing tip, which had separated along the first full rivet line inboard of the tank, was laying on the ground under the aircraft's empennage (which was sitting elevated across the very bottom of the ravine). The left wing tip, which separated along the same rivet line, was found about 20 feet further up the ravine, and also at the ravine’s very bottom. The primary impact force had been attenuated through the lower right portion of the aircraft nose, with the forward baggage area being pushed backwards into the area directly forward of the instrument panel. In addition to that damage, the right wing, outboard of the flap-aileron junction, was crushed aft, with that portion of the wing bent upward at about 15 degrees. In addition, the left horizontal stabilizer and elevator where bent upward about 90 degrees at a point located at half of their span. The remainder of the airframe sustained mostly minor damage.

There were two areas of earth at the wreckage site that had been soaked with a liquid that had a smell and feel consistent with aviation Jet-A fuel. The first was below the point where the fuel line that feeds fuel from the fuel selector valve to the engine exited the lower left side of the cabin. This portion of the aircraft structure had been crushed up and aft, and fuel was dripping slowly from this area when investigators arrived at the scene about five hours after the accident. The fuel entering the sandy soil at this location had penetrated an area about three feet wide and one foot deep. The