Iller was proficient in the -A, -B, -C, -D, and -H models of the Bell UH-1. Did he have a preference? "Well, the -B was the workhorse for us the whole time," he says. "But I liked flying the C-model because I was able to shoot back." The Vietnam Helicopter Pilots Association estimates that of the 696 UH-1Cs that served in Vietnam, 415 were destroyed, and 325 crew members were killed.