On November 13, 1995, at 1345 eastern standard time, a Beech, E55, N36SV, impacted the ground shortly after liftoff from runway 16L at Manassas Regional Airport, Manassas, Virginia. The pilot, the sole occupant, received minor injuries and the airplane was destroyed. An Instrument Flight Rules (IFR) flight plan was filed and visual meteorological conditions prevailed at the time of the accident. The flight was conducted under 14 CFR Part 91 and the intended destination was Montgomery County Airpark in Gaithersburg, Maryland. The pilot reported that earlier on the day of the accident, he flew from Concord, New Hampshire, to the Manassas Regional Airport. He stated that when he departed New Hampshire, the airplane had full fuel tanks (132 gallons useable fuel). The pilot stated that the flight from New Hampshire took approximately 2.5 to 3 hours. He calculated that he had about 60 gallons of fuel remaining, so he decided not to refuel before the short flight from Manassas to Gaithersburg, Maryland. The pilot stated that of the 60 gallons remaining, more than two thirds was in the main tanks. The pilot reported that before he departed from Manassas Regional Airport, he conducted a normal preflight inspection and followed checklist procedures to start the airplane. He stated that all preflight checklist items were performed as listed, with one exception: he switched the fuel selector valves from the "MAIN" to "AUXILIARY" position. He stated that he intended to use the fuel in the auxiliaries while on the ground for warm up and taxi, in order to retain maximum useable fuel in the main tanks for the flight to Gaithersburg. The pilot stated that his intentions were to switch back to the main tanks prior to takeoff. Postaccident investigation revealed that in November, 1993, Beech issued Mandatory Service Bulletin #2449, which stated: "Beechcraft Baron airplanes manufactured prior to 1974 and all Travel Air airplanes were equipped with auxiliary fuel tanks that were placarded for and limited to level flight only. If the auxiliary tanks are incorrectly selected for takeoff or go around from landings...it is possible for air to enter the auxiliary tank outlet, leading to power interruption. Auxiliary fuel tanks are to be used during level flight only and not for takeoff or landing." The Beech E55 Pilot Operators Handbook (POH) stated: "Takeoff and land on main fuel tanks only." A placard between fuel selector handles stated "...use aux tanks and cross feed in level flight only." One item in the BEFORE STARTING checklist states: fuel selector valves - CHECK OPERATION THEN SET TO MAIN. A witness who helped the pilot out of the wreckage recorded switch positions prior to turning all switches off. He recorded that the fuel selector valves for both engines were in the aux tank position. The pilot reported that he forgot to switch the fuel selector valves from the auxiliary position back to the main tanks prior to takeoff. He stated: "I believe that the tanks were not switched to the mains, resulting in the sudden loss of left engine power at low altitude and airspeed. The power loss caused the aircraft to snap roll to an inverted attitude at low altitude. The unusual attitude and loss of engine power resulted in the crash."