Accident Overview
On an instrument flight rules (IFR) cross-country flight, an airline transport pilot and a pilot-rated passenger departed runway 4 in a Cessna 340A. Concurrently, a private pilot and a pilot-rated passenger departed runway 36 in a Cessna 172M on a visual flight rules repositioning flight. The airport was non-towered, and the runways converged and intersected near their departure ends. Visual meteorological conditions prevailed.
Witness and Pilot Reports
A witness reported that both aircraft announced their takeoff intentions on the common traffic advisory frequency (CTAF), but the transmissions were not recorded. The Cessna 340A pilot's transmission occurred about 10 to 15 seconds before that of the Cessna 172M pilot. The witness stated the Cessna 172M pilot's transmission was not clear, though the witness was distracted at the time. Both occupants of the Cessna 172M later stated they were monitoring the CTAF constantly but did not hear the Cessna 340A pilot's transmission, nor did they see any aircraft. Airport video captured the takeoffs: the Cessna 172M had just lifted off and was over runway 36 approaching the intersection with runway 4, while the Cessna 340A was just above runway 4 in a wings-level attitude with landing gear extended, approaching the intersection with runway 36. Immediately after, the Cessna 340A began a climbing left turn with an increasing bank angle, while the Cessna 172M continued straight ahead. The Cessna 340A then rolled inverted and impacted the ground in a nose-low, left-wing-low attitude. The Cessna 172M was undamaged and continued to its destination, landing uneventfully.
Aircraft Performance Factors
The Cessna 340A was likely being flown at the published takeoff and climb speed of 93 knots indicated airspeed (KIAS). The published stall speed for the airplane in a 40° bank was 93 KIAS. When the airplane reached that bank angle, it likely exceeded the critical angle of attack and entered an aerodynamic stall.
Wreckage and Toxicological Examination
Examination of the Cessna 340A wreckage revealed no preimpact mechanical malfunctions that would have precluded normal operation. A postcrash fire prevented determination of the radio and audio panel configuration. No discrepancies were reported with the Cessna 172M radios, and no difficulties were noted with communication between the Cessna 340A and the FAA facility that issued its IFR clearance. No known issues related to the CTAF were identified. Toxicological testing detected unquantified amounts of atorvastatin, diphenhydramine, and naproxen in the Cessna 340A pilot's liver. The use of atorvastatin or naproxen would not have impaired his ability to hear radio announcements, see the other aircraft, or affect his performance once the threat was detected. Without an available blood level of diphenhydramine, it could not be determined whether the drug was impairing or contributed to the circumstances.