Accident Overview
On December 19, 2017, at approximately 1500 eastern standard time, a Piper PA-23-250 multi-engine airplane, registration N40285, sustained substantial damage during a forced landing following a loss of engine power on the left engine. The accident occurred near Knoxville Downtown Island Airport (KDKX) in Knoxville, Tennessee. The aircraft was operated by Lakelizard Aviation Training Company, LLC, under 14 CFR Part 91 as an instructional flight in visual meteorological conditions. No flight plan had been filed.
Flight Details
Three occupants were on board: a multi-engine rated pilot receiving instruction in the left seat (serious injuries), a certified multi-engine flight instructor (MEI) in the right seat (minor injuries), and an additional certified flight instructor (CFI) observing from the back seat (minor injuries). The purpose of the flight was to practice maneuvers for the rated pilot's upcoming commercial multi-engine check ride.
Events Leading to the Accident
After completing maneuvers, the flight returned to KDKX for a Localizer approach to Runway 26. During the approach, the MEI retarded the left engine's manifold pressure to 12 inches to simulate a left engine failure. Following the missed approach point, they circled to land on Runway 26 but were too high. The student reduced the right engine to idle, selected full flaps, and began a rapid descent, crossing the runway threshold at about 500 ft above ground level. The MEI called for a go-around. The student applied full power to the right engine and attempted to fly the traffic pattern with a simulated engine failure. Shortly after initiating the go-around during the left crosswind turn, the left engine lost all power, and the propeller stopped.
Emergency Response
Upon loss of left engine power, the MEI took control, checked that the throttles, propellers, and mixture controls were full forward, and attempted to retract the flaps. However, the only hydraulic pump was powered by the left engine, and he elected not to use the emergency hand pump. He then attempted to restart the left engine but could not reach the controls from the left seat, so he asked the student to accomplish the restart while he flew the airplane. The MEI held an airspeed at Vmc (80 mph) while banking into the right engine to avoid terrain. Unable to restart the engine, he attempted to maneuver for landing on Runway 8 but could not complete the required 180° turn, flying through the extended centerline toward rising terrain. To avoid a house, he maneuvered the airplane, which subsequently impacted trees. The trees stopped forward movement, and the airplane fell to the ground, coming to rest atop an automobile. After the accident, the MEI noticed the left fuel selector was between the on and off positions.
Post-Accident Examination
Examination of the left engine revealed no mechanical anomalies or malfunctions that would have precluded normal operation. Both magnetos produced spark, and internal components showed no evidence of failure. The fuel system contained some fluid and debris, but the fuel pump was intact and free of debris. The left propeller was feathered and had separated from the crankshaft; the right propeller and hub remained attached, with one blade bent aft and the other rotated and bent forward. No evidence of mechanical malfunction was found in the airframe or engine. The gross weight at the time of the accident was 4,071 pounds. According to the Pilot's Operating Manual, single-engine climb performance with the left engine inoperative would have been about 520 ft per minute at the estimated density altitude.
Weather recorded at KDKX at 1553 included wind from 260° at 7 knots gusting 12, visibility 10 statute miles, broken clouds at 7,000 ft, temperature 61°F, dew point 46°F, and altimeter setting 30.11 inHg.