Background and Event Sequence
The pilot was unable to start the aft engine before flight. A witness suggested delaying the flight until a new starter could be obtained, but the pilot insisted on taking off, stating that he had previously performed single-engine takeoffs in the same airplane. The pilot selected an abort point on the dry, gravel runway, which was 1,940 feet long and at an elevation of 90 feet MSL. He decided to abort if the aircraft was not airborne by that point. According to the witness, as the aircraft passed the abort point, the nose wheel was lifting off the ground. The aircraft climbed to an estimated height of 50 feet, at which point the wings rocked slightly. It then passed out of sight behind a low hill and subsequently impacted in a lake.
Aircraft Configuration and Performance
The landing gear was retracted in flight, and the gear doors were shut. The rear propeller was not feathered. The Cessna 337C Owner's Manual specifies that the best rate of climb airspeed is 100 mph. For a single-engine climb with the landing gear retracted and the rear engine feathered, the manual states a rate of climb of 425 ft/min at sea level and 4,000 pounds gross weight. However, the emergency procedures for a single-engine failure after takeoff or during climb caution that the landing gear should not be retracted until all immediate obstacles are cleared, regardless of which engine is out. Additionally, the drag penalty with landing gear doors opened and gear partially extended is greater than with gear fully extended, leading to rate-of-climb penalties of -240 ft/min and -110 ft/min, respectively. There is no published procedure for taking off with either engine inoperative.
Pilot Toxicology
Postmortem toxicology samples revealed the presence of Chlorpheniramine, an over-the-counter medication known to cause drowsiness and impair cognitive and motor tasks.