We tend to ignore the 'also rans'. When the US entered the European War in 1940, there was a scramble to re-equip with twin-engined attack bombers. The single-engined Northrop A-17As were clearly inadequate and the twin-engined Douglas A-20s were not yet coming off the lines. The best-known outcome of this was the rushing into USAAC service of the Martin A-22 which was being built for export to the French. Less well-known was an unsolicited bid to the Air Corps from an unusual source.
The Bell-Lockheed Aircraft Company was a joint venture firm formed specifically to develop a Bell concept which would use unchanged components supplied by Lockheed Vega. In brief, Bell Aircraft proposed to rapidly develop a new attack aircraft by combining a new, slimmer fuselage with the tail surfaces, wings, powerplants, and undercarriage of the Lockheed Model 14 airliner. A military derivative of the Model 14 - the
Hudson - had already entered British service as a patrol bomber. Bell's version was to be faster and better streamlined.
The initial draft was effectively a slimmed-down version of Bell's
Airacuda multi-seat fighter married to Lockheed flying surfaces. The fuselage design went through several permutations, none of which much impressed the Air Corps. Eventually, Lockheed Vega's Burbank drafting office took over from Bell and undertook a major re-design. The 4-seat Bell concept was reduced to a crew of three - with the pilot also acting as bomb-aimer, the navigator handling twin waist-blister guns, and the radio-operator manning a belly gun position.
Although intrigued by the 're-use' of airliner components, the USAAC concluded that the Bell-Lockheed BV-14M concept offered nothing not already found in the Martin A-22. However, the Model 14
did later see Air Corps service - in the form of the A-28. Despite its attack designation, this A-28 was an 'Americanized'
Hudson patrol aircraft.
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(Added) It occurred to me, belatedly, that my RW Martin 177A project could have also been an 'also-ran'. For those interested in the M-177A:
http://beyondthesprues.com/Forum/index.php?topic=351.msg162320#msg162320