Amateur-built Glassair III N2YT accident near Manassas, Virginia

Probable cause

The pilot's failure to maintain aircraft control while attempting an emergency landing after takeoff. Contributing to the accident was the pilot's inadequate preflight inspection and distraction due to a separated fuel cap in flight.

NTSB analysis

The pilot/owner stated that he conducted a "thorough pre-flight inspection" of the experimental amateur-built airplane, which was fully fueled for the accident flight. Engine start, taxi, and all other preflight activities were unremarkable. Just after takeoff from the controlled airport, the passenger noticed fuel venting as the right wing fuel cap had separated from the filler neck, and he informed the pilot of his observation. The pilot requested an emergency landing on the departure runway, in the direction opposite the takeoff direction. The two tower controllers saw the airplane start to turn, and then descend "fast" into trees just beyond the airport. Total flight duration was approximately 1 minute. The pilot told investigators that the airplane handled "erratically" due to the venting fuel, and that he "decided to perform a forced off field landing." Postaccident examination revealed that the fuel caps and filler necks were not placarded in accordance with the kit manufacturer's guidance concerning cap orientation. Subsequent testing of the right main fuel cap did not reveal any anomalies. Available evidence did not support the pilot's perception that the fuel venting constituted an extremely time-critical situation that rapidly resulted in a significant fuel imbalance, and a lateral control problem. The pilot's response to the fuel venting resulted in his preoccupation with requesting and executing an immediate return to the airport.

Text from the NTSB. Open the NTSB docket for ERA09LA370 for the full record.