A twin engine Gulfstream One turbo-prop made a belly landing about 100 feet short of a North Las Vegas runway at 0914 5 May. One of the two passangers aboard - who had no flight experience in a multi engined aircraft - took control of the aircraft, after the pilot took ill while en route to San Diego. Reports indicated that the pilot suffered a heart attack during flight and subsequently died at a local Las Vegas hospital. The passanger is intimated as having had in a previous life stick time in gliders (but never in any powered aircraft -...