On September 21, 1996, at about 2000 eastern daylight time, a Cessna 182C, N2731G, sustained substantial damage when it departed the right side of the grass runway and collided with parked road grading equipment at Hanover Airport, in Hanover, Pennsylvania. The commercial pilot, the sole occupant, reported no injuries. Visual meteorological nighttime conditions prevailed for the flight, no flight plan was filed. The flight operated under 14 CFR Part 91, and originated from Hanover, Pennsylvania, at approximately 1940. The purpose of the flight was to drop parachutists. The pilot stated that he departed from Hanover with 4 skydivers on board the airplane. After the skydivers exited the airplane at 10,000 feet mean sea level, the pilot returned to land at Hanover. He stated that he landed normally on runway 9, but "...following the landing I noticed an area of rough ground...before I could react, I ran into a piece of heavy equipment... ." The right wing of the airplane struck the front of the parked road grading equipment. The pilot stated that it was dark night and winds were calm when the accident occurred. The Federal Aviation Administration Inspector stated that the road grading equipment was located about 50 feet south of the 100 foot wide grass runway 9. He stated that there were only four functioning runway lights on runway 9, "...two lights at the approach [end] and two lights along the north edge of runway 9."