Bell FM-1 Airacuda
Designed by Robert J Woods, the FM-1 Airacuda was a five-seat long-range bomber destroyer powered by two engines mounted as pushers. The Airacuda accommodated two gunners in forward extensions of the engine nacelles, with access along wing crawlways to the fuselage in the event that it proved necessary to evacuate the nacelle gun positions.
Airacuda with Larry Bell (3rd from right)
Initially, Larry Bell envisioned his aircraft to fly 300 miles per hour at about 20,000 feet with turbosupercharged Allison engines. This was drastically cut when the Air Corps ordered a scaled-down Allison to be used instead with the reason being that the turbosupercharger proved quite volatile and explosive in the YFM-1 when tested. This effectively destroyed any performance the Airacuda could achieve, bring the ceiling down to 12,000 feet and a top speed barely reaching 270 miles per hour.
The Airacuda was built around the ability carry a 37mm cannon in each nacelle position, manned by a crewmember. Additional weaponry consisted of 2 x 12.7mm heavy caliber air-cooled machine guns and 2 x 7.62mm general purpose machine guns.
It was found that a considerable amount of smoke filled the nacelle crewmembers position when the 37mm cannon armament was fired.
The prototype, the XFM-1 powered by two 1150hp Allison V-1710-13 12-cylinder liquid-cooled engines driving three-blade propellers via 1.62m extension shafts, was flown on 1 September 1937. Twelve evaluation models were ordered, nine as YFM-1s and three as YFM-1As which differed in having tricycle undercarriages. Power was provided by 1,150hp Allison V-1710-23s, but three YFM-1s were completed with V-1710-41s of 1,090hp as YFM-1Bs. The 12 YFMs were delivered to the USAAC between February and October 1940, and their armament was one 37mm T-9 cannon with 110 rounds in each engine nacelle, one 7.62mm M-2 machine gun with 500 rounds in each of the retractable dorsal turret and ventral tunnel positions, and one 12.7mm M-2 gun firing from each of the port and starboard beam positions. Twenty 13.6kg bombs could be accommodated internally.
Despite the shortcomings - and at least two being lost to accidents - the Airacuda fielded one entire operational squadron though only operating in 1938 through 1940 and were eventually removed from service in 1942 - used as ground crew trainers. Beyond several photo opportunities across the country, the Airacuda never fulfilled its purpose of bomber-interceptor and destroyer and never would see combat action in the Second World War. All were eventually scrapped with only 1 prototype and 12 production models ever existing.