Cessna 310Q | N8242Q

The DTSB determines the Probable Cause of this accident to be Pilot Error, in that the accident pilot did maneuver the aircraft well below DMMS speed, whereupon he stalled and the aircraft spun, at an altitude from which a recovery was not possible. The accident pilot had purchased the plane from Alaska and had made numerous similar flights in anticipation of the start of the annual inspection by a third party. Previous flight path altitudes and speeds were very similar, always involving a pattern of straight and level flight, followed by a 360 degree turns. On the accident flight, the pilot returned to his departure airport and flew straight in visual approach for runway 33. As he approached the field, his speed was normal and another flight training aircraft also reported to be inbound for the same runway from the southwest. Unable to acquire the 310 visually, the flight training aircraft initiated a left hand turn to fly away from the airport. At 1.6 nm southeast of the runway, the accident aircraft slowed significantly and announced on the Unicom frequency “making a right 360” and then initiated a right hand turn. However, only 180 degrees of the turn was completed and the accident aircraft flew southeast at a very slow speed. At about 3.4 nm southeast of the runway, the accident aircraft initiated another right hand turn to rejoin final, but went significantly through the extended centerline of runway 33. The flight training aircraft acquired the accident aircraft visually just prior to the crash and observed the rotation of the spin to impact, and the resultant smoke. The accident aircraft gave no indication of any abnormal or emergency via radio. It is likely that the accident pilot became alarmed upon becoming aware of another aircraft in the vicinity, and began to focus on altering his approach, and searching for the other aircraft. The flight obviously operated significantly below blue line on this twin during the final moments of flight. Blue line is the same approximate speed as DMMS in most piston twins, and is often referred to as the min speed to be honored until on final. Somehow, the accident pilot lost his speed awareness, and possibly overbanked in an effort to rejoin final after going through final.

The DTSB recommends that all pilots of all aircraft rehears and condition themselves to be aware of any distractions, and to mark DMMS speed, and to honor DMMS speed. The DTSB also recommends that pilots operating at uncontrolled fields specifically do “not” make 360 degree turns in the traffic pattern as a method of collision avoidance. Below 2500 AGL: Max 30 degrees angle of bank, minimum speed to fly is DMMS, do not initiate 360 turns in the pattern.