Losing out to the A-10-the little-remembered Northrop YA-9....

It also ran; this aircraft was Northrop's entry into the competition for the Air Force's attack aircraft; for more info., see my article at: http://inflight.squarespace.com/aviation-ancestry/?currentPage=4

Photo by Scott Schwartz, all rights reserved. 
This aircraft is on display at the March Field Air Museum.