The Koizumi Se100K is a modification of the KS9K Carrier-Based fighter, manufactured by the Koizumi Aircraft Company and operated by the Empire of Japan from 1944 to 1948. It was created for the Imperial Japanese Army. Despite the large amount of modifications, it still kept its A7K designation, as it too was serviced by the Navy.
Design and Development
In the Koizumi designation "Se100K", "Se" refers to Land-based fighter series, and "K" indicated the designer of the aircraft, Koizumi.
Developed from the A7K2 Naval fighters, the Se100K is a land-based interceptor fitted with a heavier engine which boosts its performance on higher altitudes. It also has an increased wingspan.
The IJAAS found the A7K fighters fit for their needs of combat, however they needed modifications that allows the fighter itself to intercept high altitude American bombers. Adding the Koizumi B7 engine attached to Koizumi Heavy Fighters and increasing the wingspan converts the A7K Naval fighters into Land based interceptors perfect for the role.
Created as a mid-altitude interceptor, the A7K4 has an armament of two 20mm cannons and one 30mm cannon. This is the first variant that used an inline engine to use a 30mm nose cannon.
Listed as the enhanced variant of the A7K4, the Kyusen-II is a mid-high altitude interceptor with an armament of four 20mm cannons and a 30mm cannon, It uses a stronger engine than the variant before and was noted for its loud engine sound instilling fear to fighters and bombers nearby.