Accident Overview
Two agricultural turbine-powered aircraft, a bi-plane and a low-wing airplane, collided in-flight while en route to their respective destinations. The weather was reported as visual flight rules (VFR). No witnesses to the event were reported.
Aircraft and Pilots
The bi-plane was a Grumman G-164A. Its pilot held a commercial certificate and had 5,700 total flight hours. The low-wing airplane was an agricultural turbine-powered low-wing aircraft; its pilot also held a commercial certificate with 12,300 total flight hours.
Circumstances
The bi-plane pilot had completed an aerial application run and was returning on a northerly heading to the municipal airport to pick up another load of fertilizer. According to the aircraft owner, it was typical for the pilot to fly between 200 and 300 feet above ground level en route. The low-wing pilot departed a private airstrip west of the municipal airport, heading in a southeasterly direction to deliver an aerial application load. The two aircraft collided while en route.
GPS Data
The bi-plane was not equipped with a GPS logging unit at the time of the accident. The GPS memory card from the low-wing airplane was sent to the manufacturer for download, but the unit was not recording information, so no data were available.
Toxicology
The Federal Aviation Administration's Civil Aerospace Medical Institute conducted toxicology tests on the remains of the Grumman G-164A pilot. Tetrahydrocannabinol (THC, the active component of marijuana) was detected in heart and lung tissue. Tetrahydrocannabinol carboxylic acid (THC-COOH, a marijuana metabolite) was detected in lung, heart, and urine samples. The testing indicated that the pilot had recently used marijuana, which resulted in his impairment.