On August 10, 2000, at 1230 hours Pacific daylight time, a Piper PA-28R-200, N200EG, landed short of the approach end of runway 22 at the Catalina Island Airport, Avalon, California. During the sequence the right wing was damaged and the right main gear was sheared off. The airplane, owned and operated by the pilot under 14 CFR Part 91, sustained substantial damage. The private pilot and two passengers were not injured. Visual meteorological conditions prevailed for the flight, and no flight plan was filed. The flight departed the John Wayne-Orange County Airport, Santa Ana, California, about 1145 as a flight to Catalina Island for lunch. The Catalina Island airport is located on the top of a mountain near the island's isthmus at an elevation 1,602 feet msl. Steeply down sloping terrain surrounds the airport on three sides and the terrain at the approach end of runway 22 is very precipitous down to the ocean below. The first 2,000 feet of runway 22 slopes up, with the remainder level, and is equipped with a pulsating visual approach slope indicator. The steady white on glide path indication provides a 3-degree glide path. The pilot stated the approach was perfectly normal with the visual approach indicator solid white and a normal approach speed of 80 mph. He estimated the winds to be 10 knots about 45 degrees off the runway heading. As the aircraft approached the cliff near the end of runway 22, it was forced down by a downdraft or wind shear causing a sudden loss of altitude. The pilot applied full power and increased pitch but was unable to prevent contact with a weeded area short of the runway. He also stated there was nothing mechanically wrong with the airplane. In an interview with a deputy from the Los Angeles County Sheriff's Department, the pilot stated that as he came over the cliff edge for landing, the airplane was caught in a downdraft. He estimated that he lost approximately 30 feet of altitude and could not arrest the descent rate prior to contacting the ground. The airplane landed hard approximately 20 feet short of the approach end of the runway, the right wing struck the ground, and the right main landing gear was sheared off. The airplane came to rest in bushes at the approach end of the runway.