On May 20, 1996, about 1435 eastern daylight time, a Piper PA-32, N9164B, registered to SAF T Flyers Inc., operating as a 14 CFR Part 91 personal flight, crashed during a forced landing in the vicinity of Jacksonville, Florida. Visual meteorological conditions prevailed and an IFR flight plan was filed. The airplane sustained substantial damage. The commercial pilot sustained serious injuries, and the two passengers sustained minor injuries. The flight originated from Craig Municipal Airport, Jacksonville, Florida, about 5 minutes before the accident. The pilot stated to the FAA, he departed Craig, IFR en route to Vero Beach, Florida. Shortly after being handed off to departure control, he advised the controller that two engine cylinders had stopped producing power. The controller provided radar vectors back to Craig, and he made a visual no flap approach to runway 32. The approach was "extremely hot." He attempted to reduce engine power with negative results. The airplane touched down half way down the runway at about 80 knots, and started sliding and fishtailing from left to right. He initiated a go-around, became airborne, and made a climbing right turn in an attempt to return to the airport; however the engine was not producing sufficient power to sustain flight, and he elected to make a forced landing to a highway. The airplane appeared to descend rapidly as if in a stall, and impacted with trees and the ground. The General Aviation Manager for the Jacksonville Port Authority, located at Craig Airport, stated he was at the fire station when the control tower informed them about N9164B. He left the fire station in a fire truck and went to the vicinity of runway 32. N9164B was observed on about a 1 mile final. The airplane crossed the end of the runway very fast , touched down about 1,000 feet down the runway on the nose wheel, and "wheel barrowed" for some distance. "The aircraft reached the end of runway 32, and lifted back into the air and climbed straight ahead to approximately 100 to 200 feet and started a right turn. I knew the airplane would not make it because of the nose high attitude and lack of airspeed. The airplane started to descend and the right turn increased, and the nose dropped to about 30 to 40 degrees nose low and went into the trees." Review of the engine logbook revealed the engine has not been disassembled since it was manufactured. The engine has accumulated 920 total hours. Examination of the crash site by the FAA revealed the airplane collided with trees in a nose low attitude and came to rest on a heading of 190 degrees magnetic. The propeller and engine assembly separated and was displaced to the right of the main wreckage. Torsional twisting, "s" bending and chordwise scarring was present on all propeller blades. All propeller blades were bent aft and two propeller blade tips were curled forward. The left wing separated at the wing root and the right wing remained attached to the cabin structure. The left fuel tank was ruptured, and the right fuel tank was not ruptured. Examination of the airframe, flight control system, and flight control quadrant revealed no evidence of a precrash mechanical failure or malfunction. All components necessary for flight were present at the crash site. Continuity of the flight control system was confirmed for pitch, roll, and yaw. Examination of the engine assembly by the FAA revealed the rocker arms on the No. 1 and No. 2 cylinders would not operate when the crank shaft was rotated by hand. All engine cylinders were removed to examine cam shaft condition and operation. The piston in the No. 5 cylinder had a large section of the piston skirt and internal areas of the piston pin boss missing. The piston pin plugs were installed on the forward side of the piston allowing the unprotected ends of the pins to rub against the cylinder. Examination of the No. 3 piston revealed the piston pin plugs were installed in the same configuration, however, the piston bosses had not failed. The remaining cylinder assemblies were correctly installed. Examination of the No.3 and No. 5 cylinder assemblies was performed by the NTSB materials laboratory. The examination revealed that the two piston plugs were installed on the forward sides of both pistons allowing the unprotected ends of the pins to rub against the cylinder walls. The No. 5 cylinder outer portion of the pin boss was broken off on the aft side of the cylinder. Binocular microscopic examination revealed that the fracture was not covered with combustion deposits and contained no evidence of preexisting cracking. Further examination disclosed that the inner portions of both the aft and forward pin bosses were also broken off indicative of fatigue cracking. (For additional information, see NTSB Metallurgist's Factual Report No. 96-163.) The No. 3 and No. 5 cylinder and piston assemblies were released to Faith A. Collins, Sample International, on October 7, 1996.