Mitsubishi B1M, c. 1925-35
From the wiki: “The Mitsubishi 1MT was a Japanese single-seat triplane torpedo bomber built by Mitsubishi for the Imperial Japanese Navy Air Service. Designed by the former Sopwith designer Herbert Smith, it was intended for use aboard the Japanese aircraft carrier Hōshō, the world’s first commissioned ship that was designed and built as an aircraft carrier.
“The 1MT1N (the ‘N’ designated a naval aviation configuration) flew for the first time in August 1922 and it entered service as the Navy Type 10 Torpedo Bomber or Carrier Attacker. Twenty aircraft were built.
“It could climb to almost 20,000 feet thanks to its 450-horsepower Napier Lion engine, and was capable of carrying a 1-ton torpedo, but had two major problems: the triplane was hard to fly, and (amazingly) it could not take off while carrying a torpedo. The IJN decided not to commission the 1MT into service, and Mitsubishi enjoyed more success the next year with the B1M biplane torpedo bomber.”
Maximum speed: 209 km/h
Service ceiling: 6,000 m