History of Flight
On February 23, 2019, about 1243 eastern standard time, a STOL Aircraft Corp UC-1 amphibious airplane, N65NE, was substantially damaged when it impacted a house in Winter Haven, Florida. The flight instructor was fatally injured, the commercial pilot receiving instruction sustained minor injuries, and one person on the ground was seriously injured. The flight was conducted under 14 Code of Federal Regulations Part 91 as an instructional flight for initial multiengine-sea training.
The pilot receiving instruction stated that before takeoff, the instructor advised a simulated engine failure would be introduced during takeoff or climb. Shortly after takeoff, at about 200 to 300 ft above ground level, the instructor reduced the left engine throttle, and the left engine subsequently lost all power. The pilot and instructor identified the failed engine, and the instructor took control, selecting a forced landing site. The pilot reported they were unable to achieve single-engine climb performance; he was retracting the landing gear but did not have time to retract the flaps.
During descent, the instructor attempted to restart the engine unsuccessfully and determined the airplane would not reach the initially selected site. The instructor then chose a lake to the airplane's left as an alternate site. The pilot stated that during the left descending turn, the airplane slowed to Vmc (minimum control speed with one engine inoperative), the left wing dropped, and the airplane impacted a house, seriously injuring an occupant.
A witness at the departure airport reported observing the airplane fly overhead with both propellers rotating, then the left propeller stopped. She saw the airplane sink in a descending left turn until it disappeared from view.
Aircraft Information
On January 23, 2019, one month before the accident, the engine total time since major overhaul was 2,113.9 hours. A Lycoming Service Instruction specified a time between overhaul of 2,000 hours for that engine model.
Wreckage and Impact Information
The airplane came to rest inside a house in a near-vertical, nose-down attitude. All major components were accounted for. The cockpit area was destroyed and crushed inward; the top of the fuselage between the engines was crushed inward. The fuselage beyond the fifth seat was intact and undamaged. The throttle quadrant separated during impact. The wings remained attached but were removed for recovery. The flaps were found in the takeoff position. Control continuity was traced from the cockpit through several cable breaks to all flight control surfaces.
The right wing leading edge inboard of the engine was crushed inward; the front and inboard side of the cowling was crushed. The right engine propeller blades displayed chordwise scratching and tip curling. The right wing outboard of the engine was undamaged. The left wing leading edge inboard of the engine was crushed; the left propeller blades were feathered and undamaged. The outboard portion of the left wing displayed wrinkled skin and upward folding, and the wingtip was crushed inward.
Both engines were rotated by hand at their propeller hub, and continuity was confirmed through the powertrain to the valve train and accessory section. Compression was confirmed on all cylinders. All ignition harness leads were intact. The right engine's magnetos produced spark at all terminal leads when manually rotated. A test run of the left engine was attempted using an external battery, controls, and fuel supply; the engine started immediately, accelerated smoothly, and ran continuously at all selected power settings. No evidence of preimpact mechanical malfunction was noted.
Additional Information
FAA pamphlet FAA-P-8740-66, *Flying Light Twins Safely*, defines the critical engine as the one whose failure most adversely affects performance or handling qualities. On twin-engine airplanes with conventional clockwise rotation (viewed from the cockpit), the left engine is critical. Vmc is the minimum flight speed at which directional control is possible with a bank of no more than 5° when the critical engine is inoperative and the remaining engine is at takeoff power. The pamphlet notes that light twins with one engine inoperative perform marginally and may not climb at all; there is no requirement for maintaining altitude in takeoff or landing configuration with one engine inoperative. It advises that low-altitude engine failure is risky and that simulated failures below 400 ft agl should be approached with extreme caution, with failures below 200 ft agl reserved for simulators.
Medical and Pathological Information
Autopsy of the flight instructor by the Polk County Medical Examiner determined the cause of death as blunt impact injuries. Toxicology testing at the FAA Forensic Sciences Laboratory was negative for carbon monoxide and ethanol. Amlodipine, a non-impairing prescription blood pressure medication, was identified.