Bell YFM-1 Airacuda
The Airacuda was unveiled in the late 1930s. People in the aviation world, which was still developing at the time, were excited to unveil this monster to the public due to its "revolutionary" qualities. It was equipped with a wide array of guns and engines that could easily qualify it as a fighter jet.
The flaws of the jet outweighed the positives. It would overheat quickly which put the gunner in a very precarious and dangerous position. Whenever the weapons were used, the exhaust and smoke would quickly fill up the cabin. Needless to say, it was a bust.