B4Y file photo [13853]


ManufacturerYokosuka Naval Air Technical Arsenal
Primary RoleTorpedo Bomber


ww2dbaseThe B4Y carrier torpedo planes were designed by Sanae Kawasaki at the First Naval Air Technical Arsenal at Yokosuka, Japan as the response to the 1932 and 1934 Japanese Navy requirements for a new torpedo bomber to replace the aging B3Y design. These new biplanes had metal structures and mixed metal-fabric skin; they were each manned by a crew of three, with the pilot in the open front cockpit and the navigator and the radio operator/gunner in the enclosed rear cockpit. After the naval arsenal in Yokosuka produced the first five prototypes, production responsibilities were given to Nakajima (built 37 between 1937 and 1938), Mitsubishi in Nagoya (built 135 between 1937 and 1938), and the 11th Naval Air Arsenal in Hiro (built 28 in 1938); a total of 205 aircraft were built. They were equipped aboard carriers Akagi, Hosho, Kaga, Ryujo, Soryu, and Unyo, and with the ground-based 13th and 15th Air Groups. At the opening chapters of the Second Sino-Japanese War, B4Y1 biplanes were the aircraft responsible for the attack of gunboat USS Panay in Nanjing, China on 12 Dec 1937. They remained primary carrier torpedo bombers of the Japanese Navy until 1940 when they were replaced by the B5N design. Between 1940 and 1943, they were largely relegated to the rear as trainer aircraft, with the exception that they remained aboard Hosho and Unyo. Those aboard Hosho participated during the Battle of Midway.

ww2dbaseThe Allied codename for this aircraft was "Jean".

ww2dbaseSource: Wikipedia

Last Major Revision: Jan 2012


MachineryOne Nakajima Hikari-2 9-cyl air-cooled radial engine rated at 840hp
Armament1x7.7mm rear Type 92 machine gun, 1x800kg torpedo or 500kg of bombs
Span15.00 m
Length10.15 m
Height4.36 m
Wing Area50.00 m
Weight, Empty2,000 kg
Weight, Loaded3,600 kg
Speed, Maximum278 km/h
Service Ceiling6,000 m
Range, Normal1,575 km


B4Y aircraft at rest at an airfield, date unknownB4Y torpedo bomber of carrier Kaga, circa late 1930sJapanese Navy Type 96 biplane fighter flying over carrier Kaga, off China, 1937-1938A5M2b fighters and B4Y1 torpedo bombers of the Japanese Navy 12th Air Fleet at rest, 1943-1945

Did you enjoy this article? Please consider supporting us on Patreon. Even $1 per month will go a long way! Thank you.

Share this article with your friends:


Stay updated with WW2DB:

 RSS Feeds

Posting Your Comments on this Topic

Your Name
Your Email
 Your email will not be published
Comment Type
Your Comments
Security Code


Note: We hope that visitor conversations at WW2DB will be constructive and thought-provoking. Please refrain from using strong language. HTML tags are not allowed. Your IP address will be tracked even if you remain anonymous. WW2DB site administrators reserve the right to moderate, censor, and/or remove any comment. All comment submissions will become the property of WW2DB.

Search WW2DB & Partner Sites
B4Y Torpedo Bomber Photo Gallery
B4Y aircraft at rest at an airfield, date unknown
See all 4 photographs of B4Y Torpedo Bomber

Famous WW2 Quote
"The raising of that flag on Suribachi means a Marine Corps for the next 500 years."

James Forrestal, Secretary of the Navy, 23 Feb 1945