The number of helicopters destroyed or damaged during the operation shocked the proponents of U.S. Army aviation and prompted a reevaluation of basic airmobile doctrine. The 101st Airborne Division alone, for example, had 84 of its aircraft destroyed and another 430 damaged. During the operation American helicopters had flown more than 160,000 sorties and 19 U.S. Army aviators had been killed, 59 were wounded and 11 were missing at its conclusion. South Vietnamese helicopters had flown an additional 5,500 missions. U.S. Air Force tactical aircraft had flown more than 8,000 sorties during the incursion and had dropped 20,000 tons of bombs and napalm. B-52 bombers had flown another 1,358 sorties and dropped 32,000 tons of ordnance. Seven U.S. fixed-wing aircraft were shot down over southern Laos: six from the Air Force (two dead/two missing) and one from the Navy (one aviator killed).