20010310003929A

(.19) On March 10, 2001, at 1143 hours MST, an air tractor AT-802, N6059L, collided with a vehicle on landing at a private agricultural landing strip in Maricopa, Arizona. The commercial pilot was not injured. The flight was operated by sarita aerial contractors under 14 CFR part 137. The a/c was substantially damaged. The aircraft departed the private agricultural strip at an undetermined time and was returning to the same strip when the accident occurred. Visual meteorological conditions prevailed for the flight. No flight plan was filed. The pilot stated that during his landing flare, the propeller moved to the feather position when he closed the throttle. The resulting loss of drag caused him to float much farther than normal. He attempted to redirect the aircraft to a field, but was unable to avoid striking a vehicle parked at the end of the runway. (-23) pilot reported during landing aircraft propeller went to feather and that the a/c floated down the runway. The pilot then realized that he was going to land long and that he was going to run off into water at the end of the runway. He then decided to veer off the runway to the right at which time his left wing impacted a parked truck. The a/c then spun around and came to rest about 300' from point of impact. See attached pilot statement. A/c was taken back to the manufacturer where they performed an engine run with the oversight from the okc-mido. No defects were noted during this test. (.4) the orientation of the runway was 340 degrees. The weather at the nearest reporting station indicated that the winds were from 100 degrees at 6 knots. This would have resulted in a 4-knot rear quartering tailwind and a 2-knot crosswind from the right. Using the performance data listed in the airplane's pilot operating handbook, the landing distance was calculated to be 2,109 feet, without using reverse. The gila river west runway on which the accident occurred was 2,400 feet long. Assuming that the airplane was flown at the reference speed of 73 knots, with no wind, and touched down on the threshold, there would have been only 291 feet remaining on the runway. The tailwind present at the time of the accident would have increased the landing distance required, and thereby reducing the available runway. The presence of an irrigation sump at the end of the runway would have eliminated any margin for error, and made it impossible to overrun the runway safely. The placement of a truck along the side of the runway at the departure end further limits available options in the event of a long landing or overrun. Under the conditions at the time of the accident, there would have been no allowance for error either in pilot technique, or in a real or perceived mechanical malfunction. These factors would force the pilot to make sudden, last minute maneuvers to avoid obstacles at the end of the runway. During an engine inspection, performed by factory personnel, and witnessed by an inspector from the federal aviation administration southwest manufacturing district office (FAA mido-41), the engine was operated up to 30 percent of its power range with no anomalies noted. The power was reduced to idle several times and the propeller did not feather. The propeller operated throughout the operating range, including beta, with no defects noted. It was noted that with the power lever in the full aft position, the beta plunger was slightly depressed. This may have been enough to allow the propeller to go slightly past the low pitch stop, toward reverse, when the power lever was pulled back to the idle position. It was observed that rubbing had occurred between the two controls. The FAA inspector and assisting personnel attempted to force the throttle lever to move the propeller control lever aft. The two levers did move aft together, only when the power lever was pulled inboard against the propeller control lever. However, the propeller control lever could not be made to move past the feather detent. If the throttle had been closed, the propeller would move to the low pitch (high RPM) position even with the propeller control pulled aft to the control stop.