The Aichi B7A Ryūsei (流星, "Shooting Star") (Allied reporting name "Grace"), was a large carrier-borne torpedo-dive bomber designed and produced by Japanese aircraft manufacturer Aichi Kokuki. It was operated by the Imperial Japanese Navy Air Service (IJNAS) during the Second World War. Designed to replace the Yokosuka D4Y dive bomber and the Nakajima B6N torpedo bomber, work began on developing the B7A in 1941, just prior to the start of the Pacific War. The B7A was furnished with dive brakes and a folding wing, while power was provided by a single Nakajima NK9C Homare 12 18-cylinder radial engine. Armaments were stowed both in an internal bomb bay and on external attachment points, permitting the carriage of munitions such as the Type 91 torpedo, while the defensive weapons comprised a pair of cannons and a single flexibly-mounted machine gun. In spite of its size and weight, the B7A was a relatively fast and agile aircraft. In May 1942, the prototype B7A performed its maiden flight; while engine-related difficulties delayed quantity production of the type, the aircraft demonstrated strong performance in both handling and speed once fitted with an appropriate powerplant. By the time the B7A entered service in late 1944, Japan's military circumstances had declined substantially. Specifically, there was a shortage of suitably-equipped aircraft carriers (most of the IJN's carriers lacked the appropriate arresting gear), especially after the losses of Taihō and the Shinano in 1944, which meant that the type would operate primarily from land bases instead. Furthermore, the B7A was only produced in only small numbers, in part due to the destruction of Aichi's facility in Funakata. Thus, it had relatively little chance to distinguish itself in combat prior to the Surrender of Japan in August 1945.