On June 18, 1996, at 2010 central daylight time, a Piper PA-28-180, N6634J, registered to and operated by Aero Dynamics Inc., of Arlington, Texas, under Title 14 CFR Part 91, collided with a fence and a vehicle during engine start at Arlington Municipal Airport, Arlington, Texas. The commercial pilot/flight instructor and the student pilot were not injured and the airplane sustained substantial damage. Visual meteorological conditions prevailed for the planned local instructional flight and a flight plan was not filed. During interviews, conducted by the investigator-in-charge, the flight instructor, operator and the student pilot reported the following information. The airplane, parked at the tiedown area of the ramp, faced a fence and parking lot. This was the student pilot's first lesson in this airplane (equipped only with hand brakes) and he was not aware of the lack of toe brakes. Previous airplanes flown by the student were equipped with hand brakes and toe brakes. During the start procedure, the instructor read the checklist, including "set brakes." The student responded "brakes" and applied pressure on the upper portions of the rudder pedals. The throttle was set at "1/2" open and when the engine started, the airplane rolled forward and to the left toward the fence. The instructor applied full aft yoke, right rudder, and hand braking; however, the airplane struck the fence and a parked vehicle. The left wing structures, the propeller, fence, and vehicle were damaged.