Lockheed Model 10A Electra, NC233Y, Northwest Airlines fleet number 60, prototype, after modification (SDASM) Published on February 24, 2014 in 24 February 1934Full resolution (1672 × 1336) ← Previous Next → The prototype Lockheed Model 10 Electra, NC233Y, after cockpit windshield modifications by Northwestern Airways, Inc. (San Diego Air and Space Museum Archives)