Only two YA-9A prototypes were built by Northrop Aviation, serial numbers 71-1367 and 71-1368. Together they completed 123 flights, totaling 146.0 flight hours during the ground attack aircraft selection. After the A-10A 'Warthog' was selected, these A-9A were transferred to the NASA Dryden Research Center before being completely retired from service on April 2, 1973. Both YA-9A's still exist today. March Field Air Museum's 71-1368 is on display, its sister ship is at Edwards AFB. The March Field Air Museum received its YA-9A in 1981 as a loan from the US Air Force.

Photo by Bob Nelson on Thursday, August 11, 1994 at the March Air Force Base, Riverside, CA.