This week in Edwards history Published May 9, 2018 By 412th Test Wing Public Affairs EDWARDS AIR FORCE BASE, Calif. -- On May 10, 1972, Fairchild Republic’s YA-10A Thunderbolt II made its first flight, flown by company chief test pilot Howard “Sam” Nelson. The twin-engine, twin-tailed ground attack aircraft was designed around the GAU-8 Avenger 30 mm rotary cannon.