 A SCARE IN THE AIR AFTER A UNITED AIRLINES BOWING JET LOST THE MAIN LANDING GEAR WHEEL DURING TAKEOFF IN LOS ANGELES. 174 PASSENGERS AND 7 CREW MEMBERS WERE ON BOARD. UNITED SAID THE PLANE LANDED SAFELY IN DENVER. THE AIRLINE SAYS THE WHEEL WAS RECOVERED AND AN INVESTIGATION IS NOW UNDERWAY. THIS COMES AFTER A UNITED FLIGHT IN MARCH ALSO LOST A TIRE MID-AIR AFTER A TAKEOFF FROM SAN FRANCISCO. NO ONE WAS HURT IN EITHER INCIDENT.