CHI95LA145

The pilot reported in his written statement that he was conducting an engine runup because the engine would not develop full power. He decided to taxi down the runway with no intention of taking off, but inadvertently became airborne. Shortly after the unintentional takeoff, the engine lost partial power, turned to the right and impacted terrain. Post-accident examination of the engine revealed evidence of heat damage and abnormal piston ring wear. There were scrape markings on the piston, piston rings, and cylinder wall. The pilot stated that he performed the cylinder and ring change and was not aware that the cylinder and ring combination were not compatible.

On May 2, 1995, at 1827 eastern standard time, a Franklin EAA Bi- Plane/P1, registered to a private owner, of Rockville, Indiana, received substantial damage on impact with terrain following a takeoff to the west and experiencing a loss of engine power. The personal 14 CFR Part 91 flight was operating in visual meteorological conditions. The pilot reported minor injuries. No flight plan was on file. The local flight was on departure from the Bulter Airport, Rockville, Indiana, at the time of the accident.

The pilot reported in his written statement, that he was conducting an engine runup, because the engine would not develop full power. He decided to taxi down the runway with no intention of taking off, but inadvertently became airborne. The engine sustained a power loss shortly after liftoff.

Witnesses stated that the takeoff appeared normal until at the end of the runway, the engine sounded like it was reduced to idle power.

Postaccident examination of the engine was conducted. An FAA Inspector's report stated, "...evidence of heat damage and abnormal piston ring wear. There were scrape markings on the piston, piston rings, and cylinder wall...". The pilot said that he performed a cylinder and piston ring change and was not aware that the rings and cylinder were not compatible.