On May 3, 2003, at 1500 central daylight time, a Piper PA-18A-150 single-engine tailwheel-equipped airplane, N9789D, sustained substantial damage during a forced landing following a loss of engine power during takeoff climb, while executing touch and go landings from the Northwest Regional Airport, near Roanoke, Texas. The certified flight instructor (CFI) was not injured, and the private pilot receiving instruction sustained minor injuries. The airplane was registered to Land Aviation LLC, of Argyle, Texas, and operated by Marcair, of Roanoke, Texas. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 instructional flight. The local flight departed Northwest Regional Airport approximately 1425. The 260-hour private pilot was receiving a checkout for a tailwheel endorsement. The private pilot reported that prior to the flight, according to the cockpit fuel sight gauges, the left fuel tank indicated approximately 3/4 full of fuel, and the right tank indicated approximately 1/2 full of fuel. During the takeoff climb of the 3rd or 4th touch and go, "the engine lost power and began to sputter." The private pilot stated that the fuel selector was selected to the left fuel tank at the time the engine lost power. After the engine began to lose power, the CFI switched the fuel selector to the right tank position; however, no change in engine power was noted, and the CFI initiated a forced landing to a field. During the forced landing, the airplane impacted trees and terrain, and came to rest on its nose. An FAA inspector, who responded to the accident site, reported that the right wing and the fuselage sustained structural damage. The FAA inspector stated that the fuel system was intact, the left main fuel tank was empty, the right main fuel tank contained "plenty of fuel," and the fuel was clear of contaminants.