Nakajima P-1

The Nakajima P-1 was a Japanese single-engine, single-seat biplane built in the early 1930s for night mail flights. Nakajima developed it from its E4N3 reconnaissance seaplane after winning a January 1933 contract from Nihon Koku Yuso for eight mailplanes to fly a new night mail service. It was a mixed wood and metal landplane with fabric covering, a single-bay wing, fixed landing gear with helmet fairings, landing lights and parachute flares for night safety, and a radio receiver and beacon. Power came from a nine-cylinder Nakajima Jupiter VI radial, with some later fitted with the Kotobuki 2-kai-1. The first aircraft was completed in May 1933 and the Tokyo, Osaka and Fukuoka route opened that August. The strain on a lone pilot in a single-engined aircraft at night led to its replacement over about two years by larger twin-engined aircraft with bigger crews. Nine were built, the ninth for the Ministry of Communications.