On July 1, 1996, at 1000 central daylight (cdt) a Bellanca 17-30 Viking, N838MM, was substantially damaged during a gear up landing following a total loss of power while on base leg for landing. The airplane landed on the clearway area next to runway 22 (4,800' X 75' dry asphalt) at Chandler Field, Alexandria, Minnesota. The airplane was piloted by a commercially certificated flight instructor who was giving a checkout in the airplane to a private pilot. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 dual instructional flight was not operating on a flight plan. The private pilot reported serious injuries and the flight instructor reported no injuries. The flight departed Alexandria, Minnesota, at 0900 cdt. The airplane's owner said he was receiving dual instruction to act as pilot-in-command in the Bellanca 17-30. He said the instructor was flying the airplane as it turned onto base leg for runway 22 when the engine stopped running. The owner said the instructor landed "...within the airport perimeter, making wheels up landing." He said the instructor checked "...one of the right wing tanks, and indicated that he had plenty of gas." The instructor's written statement said they had flown "...around for approximately an hour..." before returning to the airport. During an interview with the instructor it was revealed he had allowed the owner to do an unsupervised preflight inspection. He said a mechanic reviewed the fuel system with the owner for about 45 minutes. When asked if he gave the owner any preflight ground instruction the instructor said he had spent about 6 to 10 minutes covering the flight maneuvers for the flight. The instructor said the owner had a timer that sounded an alarm when the fuel tanks needed to be switched. He said the alarm sounded during the flight and that he believed the owner had switched the fuel tank selector. He said he didn't check the owner's response to the alarm. N838MM's engine quit when the airplane was maneuvering to make its first landing. He said the owner became frustrated and that he helped him with the emergency procedures. The instructor said he switched the fuel selector from the right to left main fuel tank. The on-scene investigation revealed empty main fuel tanks. The right and left auxiliary fuel tanks were full. The Federal Aviation Administration (FAA) Principal Maintenance Inspector (PMI) stated the mechanic who gave the airplane its annual inspection said the left main tank was empty. There was no record of any fuel being added to the airplane before the accident flight. According to the PMI, each main tank holds 15.5 gallons of usable fuel. The airplane consumes about 14 gallons per hour according to the PMI. The PMI said it was estimated that the airplane had about 19 gallons of fuel in its right tank before departing on the accident flight.