IJN A7M1 Reppu (Type 17 Sam)

The final masterpiece of Jiro Horikoshi and the Mitsubishi engineering team, the Reppu. It was designed to meet the M-50 requirements which was an internal Mitsubishi specification aiming to create the successor of Zero. In July 1942 the Imperial Navy adopted the requirements into the 17-Shi specification. The airplane was expected to achieve the speed of 640 km/h at 6 000m, reach the altitude of 6 000m in 6 minutes be able of flying for 2,5 hour at 463 km/h and have the maneuverability of A6M3. The design envisioned by engineer Horikoshi was expecting the airplane to be equipped with the 18-cylinder version of the Kinsei engine which was supposed to produce 2 200BHP. As the design of the engine was delayed the Navy insisted on installing the NK9 engine on the plane and submitting it for trial. Trial handled by combat pilots confirmed that the maneuverability of the airplane at level with A6M5 and greater then A6M3. However, the airplane was lacking power and the climb to 6 000m was taking 9m 54s. At 6 450m the engine was producing 1 300bhp while 1 700bhp was expected by the engineering team to reach 17-Shi speed requirements. Due to that IJN deprioritized the work on Reppu, however the Mitsubishi team was sure that with the MK9 engine their airplane would meet all the requirements of 17-Shi and this is how A7M2 was born.