Martin Mars prototype at the Martin factory, repaired following the #3 engine fire on 5 December 1941, but still before its first flight. It is seen here still in its original configuration as a patrol bomber, complete with gun turrets and provisions for bombing. However, the aircraft was soon to be converted to XPB2M-1R transport aircraft, which involved removing all armament and armored plating, and adding extra cargo hatches, cargo loading equipment and reinforcing the decking. Photo from public domain.
This photo was added on 17 February 2019, and has since been viewed 13 times.