Accident Summary
On February 21, 2008, at 1148 eastern standard time, an amateur-built Vans RV-9A, registration N159AS, was substantially damaged when it impacted trees and terrain during a forced landing shortly after takeoff from Princeton Airport (39N) in Princeton, New Jersey. The certificated commercial pilot was seriously injured, while the passenger was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 Code of Federal Regulations Part 91.
Pilot's Account
The pilot reported that shortly after takeoff, while turning onto the crosswind leg of the traffic pattern, the engine lost power and the propeller stopped. The pilot had already activated both fuel pumps and the dual ignition switches for takeoff, so no additional emergency switches were available. The electrical system appeared to function normally, as the electronic flight instrument system and communication radios remained operational. The pilot noted that the airplane had accumulated approximately one flight hour since he had performed work on the engine and propeller reduction gearbox. With no suitable landing area within gliding range, the airplane was substantially damaged during the forced landing in a dense forest.
Post-Accident Examination
A Federal Aviation Administration (FAA) inspector at the scene observed fuel that had leaked from the airplane's fuel tanks. During the recovery process, some of the leaked fuel ignited, partially burning the wreckage. The fire was extinguished, and the wreckage was transported to the airport.
On March 4, 2008, two representatives of the engine manufacturer, under FAA supervision, examined the engine. They confirmed continuity from the rear pulley to the propeller and compression on all six cylinders. However, the wiring and other components of the electronic ignition system were heavily fire-damaged.
The FAA inspector and engine manufacturer representatives reported that the pilot/owner had recently installed a new aftermarket fuel injection/ignition system. According to the aftermarket schematic, the pilot retained an original-equipment diode bridge to provide dual electrical paths to the engine control unit (ECU) and wired it per the schematic. The original ignition system drew between 4 and 6 amperes, while the aftermarket system drew between 8 and 12 amperes. The only manifestation of a failure of the diode bridge would be on engine operation; the remainder of the electrical system would continue to function normally.
Weather Conditions
The 1153 weather observation at Trenton Mercer Airport (TTN), located approximately 10 nautical miles southwest of the accident site, included winds from 310 degrees at 6 knots, clear skies, temperature -2 degrees Celsius, dewpoint -15 degrees Celsius, and an altimeter setting of 30.41 inches of mercury.