On Thursday afternoon, September 2, 1993, at 1750 mountain daylight time, a Cessna 150M, N3305V, operated by Northstar Aviation, impacted terrain and nosed over during an emergency forced landing at Missoula, Montana. There was no flight plan filed for the local student training flight, conducted under 14 CFR 91 in visual meteorological conditions, that originated at the Missoula Airport on September 2, 1993, at 1642. The instructor pilot and the student pilot were not injured in the accident. The aircraft was destroyed. There was no fire. The instructor pilot reported the student pilot was practicing takeoff and landings on runway 25 at the Missoula Airport, and the aircraft lost engine power about 400 feet above the ground while the student was turning crosswind in the traffic pattern. The instructor initiated an emergency forced landing and the aircraft impacted rough terrain about one mile from the airport. The landing gear collapsed on impact and the aircraft nosed over. The FAA Airworthiness Inspector who examined the wreckage reported the left fuel tank contained less than 1/2 gallon of fuel and the right tank contained about 2.5 gallons of fuel. The owner's manual indicates the total capacity of the aircraft fuel tanks is 26 gallons, of which 3.5 gallons is unusable.