An experimental aircraft crashed into a house and exploded shortly after takeoff Friday, killing the pilot and two people inside the home, authorities said. The pilot of the home-built plane radioed that he was in trouble shortly after taking off from the North Las Vegas Airport, said Ian Gregor, a Federal Aviation Administration spokesman in Hawthorne, California. A review of tower audio tapes showed the pilot told air controllers that he was going down, Gregor said. Gregor said the plane couldn't gain altitude. Firefighters quickly doused an intense fire in the single-family home in a neighborhood southeast of a main runway at the airport.