On July 20, 2003, about 1050 eastern daylight time, a Piper PA-28-181, N8199D, was substantially damaged during a go-around at the Griffing-Sandusky Airport (SKY), Sandusky, Ohio. The certificated private pilot and three passengers were seriously injured. Visual meteorological conditions prevailed and no flight plan had been filed for the flight that departed Fort Wayne International Airport (FWA), Fort Wayne, Indiana. The personal flight was conducted under 14 CFR Part 91. The airplane was on approach to runway 27, a 3,559-foot-long, 60-foot-wide, asphalt runway. The pilot reported that while turning onto the final approach path, he observed a twin-engine airplane on a taxiway near the runway. The pilot was not certain if the airplane was going to utilize the runway, and elected to go-around. The pilot pushed the throttle full-forward and kept his right hand on the power quadrant. The airplane was configured with two notches of flaps during the approach, and the pilot retracted one notch of flaps. The pilot looked over his left shoulder and observed the twin-engine airplane passing under his airplane's left wing, which was approximately 300 feet above the ground, and climbing. The engine then began to "stumble," and he felt the yoke in his left hand becoming very heavy. He looked down at the power quadrant and noticed that the engine mixture control was pulled back. The pilot pushed mixture control in and lowered the airplane's nose to avoid a stall; however, the airplane struck trees about 1/2 mile beyond the departure end of the runway. The wreckage was moved to a hangar at SKY, where it was examined under the supervision of a Federal Aviation Administration (FAA) inspector. The examination did not revealed any pre-impact malfunctions of the engine and associated controls. The engine was rotated by hand and thumb compression was obtained on all cylinders. All spark plugs were removed. Their electrodes were intact and light gray in color. The right magneto generated a spark through all four of its leads when rotated. The left magneto sustained impact damage and could not be tested. The engine driven fuel pump and carburetor were disassembled with no discrepancies noted. The pilot reported 338 hours of total flight experience, which included 67 hours in the same make and model airplane as the accident airplane.