On October 4, 2019, at 1713 eastern daylight time, a Piper PA46-310P, N4385K, was substantially damaged when it was involved in an accident near Harrisburg, Pennsylvania. The private pilot and a passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
In a written statement, the pilot stated that he conducted a thorough preflight inspection and had the airplane serviced with 30 gallons of 100LL aviation gasoline. He estimated that the 122-gallon fuel system contained 77 gallons of fuel at the time of departure.
The pilot described the flight as "unremarkable." Upon arriving at the destination airport, he was cleared for a visual approach and stated that he referenced the localizer and glideslope indications for the instrument landing system (ILS) approach during the descent.
The pilot stated that he had lowered the landing gear and extended the flaps when the engine “cut out.” He switched fuel tanks and attempted to restart the engine, but was unsuccessful, and he subsequently retracted the landing gear and performed a forced landing to the Susquehanna River.
The airplane was submerged in the Susquehanna River until October 16, 2019, before it was recovered. Examination of the wreckage following recovery revealed that the airplane was intact, but the fuselage was deformed aft of the cabin door. Both wings were cut at their roots by recovery personnel. Before removal of the wings, each wing was drained of fuel and water. The left wing contained 12.5 gallons of fuel and 10 gallons of water. The right wing contained 17 gallons of fuel and 15 gallons of water.
Flight control continuity was confirmed from the flight controls to all flight control surfaces. Fuel system continuity was confirmed from the roots of each wing to the fuel metering unit. Electrical power was applied to the fuel boost pumps in each wing, and both operated when energized.
The engine spark plugs were removed from the top of each cylinder. Each spark plug displayed normal wear and evidence of exposure to water. The engine was rotated by hand at the propeller; both magneto impulse couplings "snapped," and spark was produced at the ignition leads of the top six spark plugs.
The engine examination was suspended, and the engine was removed for examination at the manufacturer’s facility. Prior to placement in the test cell, some engine components required repair or replacement due to water submersion, damage, or contamination. The engine starting motor was replaced when rotation of the propeller revealed “binding.” Ignition timing was confirmed on the left and right magneto prior to removal for drying. Once dried, they were reinstalled and timed to their as-found timing values.
Once placed in the test cell, an engine start was attempted without success. Investigation revealed that the fuel manifold was contaminated and blocked due to water submersion. The manifold was removed, disassembled, cleaned, reassembled, and reinstalled.
An engine start was attempted, and the engine started immediately, accelerated smoothly, and ran continuously at all power settings without interruption. The examination and test run revealed no pre-impact anomalies that would have prevented the engine’s ability to produce rated horsepower.
Examination of the airplane’s flight track and data downloaded from its engine data monitor revealed the airplane experienced an increase in lateral g-forces as it aligned with the final approach (localizer) course. The airplane continued its approach left of the localizer course in a right-wing down or slip configuration, consistent with compensation for the gusting wind from its right side.
According to the pilot’s operating handbook for the airplane:
Prolonged slips or skids which result in excess of 2000 feet of altitude loss or other radical or extreme maneuvers which could cause uncovering of the fuel outlet must be avoided as fuel flow interruption may occur when the tank being used is not full.