CESSNA 402B — Aguadilla, PR

What happened

About 3 months before the accident, the twin-engine airplane underwent an annual maintenance inspection during which the mechanic identified numerous discrepancies with both engines and the airframe. The airplane was not subsequently approved for flight and the owner was provided a list of the discrepancies. The purpose of the accident flight was to relocate the airplane to another airport where the pilot planned to have the discrepancies addressed. The mechanic reported that he had advised the pilot that he needed to apply for a ferry permit from the FAA in order to complete the accident flight, but there was no evidence that the pilot had obtained one.

On the day of the accident flight, air traffic control data showed that the pilot departed and climbed the airplane to about 1,500 ft mean sea level (msl). About 2 miles from the departure airport the pilot advised air traffic control of his intent to return to the departure runway due to a vibration of the right engine. The controller immediately cleared the pilot to enter the left downwind for the departure runway. The airplane then turned to the left and began a descent toward the left downwind leg of the traffic pattern. When the airplane was about a mile from the airport, the pilot reported that the airplane had an “engine failure” and that he intended to land on the departure runway, but in the opposite direction. Recorded flight track data showed that the airplane then turned directly toward the approach end of that runway and that during the final 30 seconds of track data, the airplane’s altitude and groundspeed decreased rapidly. Surveillance video captured the final few seconds of flight, and showed the airplane in a steep vertical descent and a right roll. The airplane impacted a residential area into trees, powerlines, and propane fuel tanks. After the impact, the airplane sustained significant postimpact fire damage.

Postaccident examination of the airplane revealed no evidence of any preimpact mechanical malfunctions or failures of the airplane’s flight controls. Although the right engine’s fuel manifold was damaged by thermal forces, it contained visible corrosion and remains of diaphragm material when opened. Below the fuel screen at the fuel inlet within the manifold was a large quantity of debris and foreign material that was likely present before the accident. Based on the available evidence, it is possible that this contamination resulted in the total loss of engine power to the right engine that was reported by the pilot; however, given the multiple discrepancies that had been documented with the engine prior to the flight, and the extent of the post impact fire damage to the engine, it is possible that the loss of reported loss of engine power may have been due to other unresolved maintenance issues.

The final recorded position showed the airplane about .3 miles the runway threshold at 200 ft msl and 73 kts groundspeed, on a heading of 209°. The Pilot’s Operating Handbook for the accident airplane model listed the minimum controllable airspeed as 82 knots indicated airspeed. Considering the wind information provided by air traffic control to the pilot of 090° at 10 knots, gusting to 14 knots, it is likely that the airplane’s airspeed likely decreased below its minimum controllable airspeed which resulted in a loss of control from which the pilot was not able to recover.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.