All the "Century Series" fighters were pretty tough on the pilot population, and although most types were deployed to Viet Nam, over their service lives the losses to aviation mishaps vastly exceeded combat losses (not counting the F-105 fighter-bomber, which was not a fighter first, but primarily a bomber). The delta design of the 102 and 106 required sustained high speed to fly at all, and if the powerplant hiccupped the pilot was very likely going to have a real bad day at the office, especially if that happened on departure or approach at under 500' in those days before the zero-altitude ejection seat was developed.