Accident Details
Probable Cause and Findings
A loss of engine power for reasons that could not be determined.
Aircraft Information
Registered Owner (Historical)
Analysis
On July 8, 2022, about 1530 eastern daylight time, an Air Tractor AT-502B, N50075, was substantially damaged when it was involved in an accident near Center Cross, Virginia. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 agricultural flight.
According to the pilot, before the spraying operation the airplane was fueled at Crabbe Airport (3NR4) Elizabeth City, North Carolina, before he flew to the staging airport in Tappahannock, Virginia, where he topped off the airplane with fuel and had it filled it with agriculture chemicals. Shortly after completing the final spray pass of the sixth load of the day, he turned and climbed about 350 ft agl when he heard a “bang,” and he could feel the engine lose power. He was unable to maintain altitude. The pilot lowered the airplane’s nose and maneuvered for a forced landing in an open area between trees. The pilot stated that the airplane’s speed was “too high” upon touchdown; the airplane bounced, and subsequently impacted trees and terrain before coming to rest upright.
Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the fuselage was buckled, the leading edges of both wings were crushed, and the right elevator was bent upward. The fuel tanks remained intact. When the airplane was moved during recovery, fuel flowed from the left and right wing root areas; the fuel was confirmed to be Jet-A. Flight control continuity was confirmed to all flight control surfaces from the cockpit. The rudder remained attached, and the vertical stabilizer was bent at a 90° angle to the right about midspan. The right flap was retracted, and the left flap appeared to be partially extended at a slight angle. The left wing was partially displaced. Continuity of the engine and propeller controls was confirmed. No engine debris were located within the exhaust or intakes; there was no sign of catastrophic engine failure.
A detailed examination of the engine components and accessories revealed that rotation of the power section was not possible. Smooth and noise-free rotation of the compressor was possible using the accessory gear box. The pneumatic lines were found intact and secured and the filter was free of contamination. The power turbine control was in good condition. The chip detectors, oil filter, and fuel filter were free of contamination.
Closer examination of the propeller blades revealed that each exhibited features consistent with some rotation at impact. Two propeller blades exhibited chordwise/rotational abrasion. One blade was bent aft and twisted towards low pitch near the tip. Another blade was bent aft about 90 deg and exhibited wave bends in the leading edge consistent with tree/branch strikes. The third blade was fractured about 10-12 inches from the tip. The damage was consistent with rotation and not feathered at impact.
One blade tip of the compressor turbine was broken and found adjacent to the blade indicative of impact damage. The power turbine section was in good condition and the blade tips displayed evidence of rubbing on the adjacent turbine shroud. The compressor rotated freely and was free of any abnormal noise or limitations. There was no visible damage present. The reduction gearbox rotated freely and displayed no evidence of defect. The fuel pump and fuel control unit could not be evaluated. Fuel was discovered in the engine compartment filter drain. The fuel selector valve contained residual fuel and operated normally between the detents with no binding or limitations and the detents were distinctive. Based on the engine and component examination, there was no indication of any pre-impact mechanical anomalies.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ERA22LA302