What happened
On July 10, 2009, an Ayres Corporation S2R-T34, registration N357CA, crashed in a cornfield near Craig Craft Airport in Hertford, North Carolina. The flight was being conducted for agricultural work under visual meteorological conditions. The pilot, a 37-year-old commercial pilot with extensive experience in other agricultural aircraft, was performing practice spray passes in the turbine-powered airplane.
Earlier that day, the pilot had completed a 14-minute flight performing water spray passes. For the accident flight, the pilot filled the left fuel tank with Jet A and added 225 gallons of water to the hopper tank. After several successful passes, the pilot indicated to a nearby colleague that he intended to perform more maneuvers to gain a better feel for the aircraft.
A witness observing the maneuvers reported that the propeller sound during the final pull-up and turn was unusual. While the sound typically transitioned from low to a higher pitch, during the final maneuver, the high-pitched sound persisted longer than usual, followed by a single loud impact. Shortly after, the chief pilot of the operator observed a wisp of smoke and discovered the aircraft resting inverted in a cornfield.
The investigation
Investigators examined the wreckage and found the aircraft had sustained substantial damage, with the left wing showing extensive crushing and the engine separated from the airframe. The power lever was found in the reverse position, and the propeller control was at midrange. One propeller blade had separated from the hub.
Technical analysis of the engine revealed severe impact damage to the reduction gearbox, accessories, and the gas generator case. The compressor turbine and power turbine also showed significant damage, including displaced blade platforms and fractures. Examination of the propeller showed that while the blades were in their normal operating range at the time of impact, the spinner dome had been damaged by contact with the blade counterweights.
Review of the aircraft's records showed that a PT6A-27 engine was installed, which was not specifically called for in the type certificate for the S2R-T34, though it is approved for the nearly identical S2R-T15 model. Additionally, the propeller had been reinstalled only four days prior to the accident following the replacement of a spinner dome.
GPS data from the aircraft indicated that during the final 22 seconds of flight, the altitude decreased from approximately 292 feet to 48 feet above ground level, while the groundspeed increased from 137 mph to 152 mph. The aircraft came to rest approximately 1,220 feet from the last recorded GPS position.
Findings
- The pilot was performing practice spray runs in his first flight in this specific turbine-powered model.
- The aircraft was equipped with an engine model not officially listed in the type certificate for that specific airframe.
- The pilot was killed due to multiple blunt trauma resulting from the crash.