On March 16, 2006, about 1400 eastern standard time, a Cessna 172P, N737TR, registered to and operated by Avion Air Academy, as a Title 14 CFR Part 91 instructional flight, impacted with a taxiway sign during landing at the Leesburg Regional Airport, Leesburg, Florida. Visual meteorological conditions prevailed at the time and a visual flight rule flight plan was filed. The student pilot was not injured and the airplane incurred substantial damage. The flight had originated from the Gainesville Regional Airport, Gainesville, Florida, earlier that day, about 1325 The student pilot stated he performed a normal landing. After all three wheels were down; the airplane began to veer toward the left side of the runway. He tried to applying right rudder but could not control the airplane in time before it hit a taxiway sign on the left side of the runway. The airplane then went across the runway and stopped on the grass. He secured the airplane before exiting. The flight instructor who endorsed the solo flight stated the student pilot was not authorized to land at the accident airport. The operator stated there were no mechanical failures or malfunctions to the airplane or any of its systems prior to the accident.