The Yokosuka P1Y ''Ginga'' (銀河, "Galaxy") was a twin-engine, land-based

bomber A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped from an air ...

developed for the

Japanese Imperial Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. It was the successor to the

Mitsubishi G4M The Mitsubishi G4M was a twin-engine, land-based medium bomber formerly manufactured by the Mitsubishi Aircraft Company, a part of Mitsubishi Heavy Industries, and operated by the Imperial Japanese Navy from 1940 to 1945. Its official designat ...

and given the Allied reporting name "Frances".

Design and development

The P1Y was designed by the

Yokosuka Naval Air Technical Arsenal had many names, each depending on the period of its existence, and the circumstances at that time. Many of the names were acronyms that were derived from its military name or designation, which changed from time to time. The arsenal was sometim ...

to Navy specification 15-''Shi'', calling for a fast bomber with speed matching the

Zero 0 (zero) is a number representing an empty quantity. In place-value notation such as the Hindu–Arabic numeral system, 0 also serves as a placeholder numerical digit, which works by Multiplication, multiplying digits to the left of 0 by th ...

, range matching the G4M, a 907 kg (2,000 lb) bombload, and the ability to dive-bomb as well as carry

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, ...

es. As the result, the construction suffered from excess complexity, difficulty of manufacture, and poor serviceability. Problems with the availability of enough reliable Nakajima ''Homare'' engines led to their replacement by the Mitsubishi ''Kasei'' in the P1Y2-S night-fighter version. The streamlined design of the ''Ginga'' is attributed to

Miki Tadanao Miki may refer to: Places * Miki, Hyōgo, a city in Hyōgo Prefecture, Japan * Miki, Kagawa, a town in Kagawa Prefecture, Japan * Miki, Azerbaijan, a village in Astara Rayon, Azerbaijan People * Miki (given name) * Miki (surname) * Miki Núñez ...

, an engineer who after

went on to create a similar

aerodynamic Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...

design for Japan's earliest bullet trains (

Shinkansen The , colloquially known in English as the bullet train, is a network of high-speed railway lines in Japan. Initially, it was built to connect distant Japanese regions with Tokyo, the capital, to aid economic growth and development. Beyond l ...

), while working with the Japan National Railways (JNR).

Operational history

The first flight was in August 1943. Nakajima manufactured 1,002 examples, which were operated by five '' Kōkūtai'' (Air Groups), and acted as land-based

medium Medium may refer to: Science and technology Aviation * Medium bomber, a class of war plane * Tecma Medium, a French hang glider design Communication * Media (communication), tools used to store and deliver information or data * Medium ...

and

torpedo bomber A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...

s from airfields in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the no ...

, the

Mariana Islands The Mariana Islands (; also the Marianas; in Chamorro: ''Manislan Mariånas'') are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, betw ...

, the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, the

Ryukyu Islands The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands (further divided into the Miyako and Yaeyama Islands), with Yon ...

Shikoku is the smallest of the four main islands of Japan. It is long and between wide. It has a population of 3.8 million (, 3.1%). It is south of Honshu and northeast of Kyushu. Shikoku's ancient names include ''Iyo-no-futana-shima'' (), '' ...

, and

Kyūshū is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...

. During the last stages of the war the P1Y was used as a ''

kamikaze , officially , were a part of the Japanese Special Attack Units of military aviators who flew suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, intending ...

'' aircraft against the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

during the

Okinawa is a Prefectures of Japan, prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 Square kilometre, km2 (880 sq mi). ...

Campaign in Operation Tan No. 2. A

night fighter A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time after the Second World War) is a fighter aircraft adapted for use at night or in other times of bad visibility. Night fighters began to be used i ...

version, the P1Y2-S ''Kyokko'' (極光, "Aurora"), with Mitsubishi ''Kasei'' engines, was equipped with

radar Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, Marine radar, ships, spacecraft, guided missiles, motor v ...

and ''

Schräge Musik ''Schräge Musik'', which may also be spelled ''Schraege Musik'', was a common name for the fitting of an upward-firing autocannon or machine gun, to an interceptor aircraft, such as a night fighter. The term was introduced by the German '' ...

''-style upward-firing as well as forward-firing 20 mm

cannon A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder ...

. A total of 96 were produced by Kawanishi, but due to inadequate high-altitude performance against the

B-29 Superfortress The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 ...

, many were converted back to ''Ginga'' bombers.

Survivors

A P1Y1 survives at the Smithsonian's Paul Garber Facility of its

National Air and Space Museum The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States. Established in 1946 as the National Air Museum, it opened its main building on the N ...

. While only the fuselage has been photographed several times and can be found on the internet, the wings and engines are confirmed to exist. This was one of three P1Ys that were brought back to the United States after World War II for evaluation.

Variants

The Maru Mechanic (1984), pp. 109–110.Famous Airplanes of the World (2000), pp. 29–31. ;P1Y1 ''Experimental Type 15 land-based bomber'' (15試陸上爆撃機, ''15-Shi Rikujō Bakugekiki'') : 3 of prototypes and 9 of supplementary prototypesFamous Airplanes of the World (2000), p. 26. with 1,357 kW (1,820 hp) NK9C Nakajima NK9B ''Homare'' 11 engines. Prototype #3 was later used for

Ishikawajima Tsu-11 The Ishikawajima Tsu-11 was a motorjet produced in small numbers in Japan in the closing stages of World War II. It was principally designed to propel the Japanese Yokosuka MXY7 Ohka flying bomb, a kamikaze weapon. Design and development The ...

testbed. ;P1Y1 ''Ginga'' ("Milky Way") ''Model 11'' (銀河11型, ''Ginga 11-gata'') : First model of the series. Mounted ''Homare'' 11 or ''Homare'' 12. ;;P1Y1a ''Ginga Model 11A'' (銀河11甲型, ''Ginga 11 Kō-gata'') : Mounted ''Homare'' 12, and fitted 1 × 13 mm (.51 in) Type 2 machine gun in the back defensive position. ;;P1Y1b ''Provisional name Ginga Model 11B'' (仮称銀河11乙型, ''Kashō Ginga 11 Otsu-gata'') : Converted from P1Y1a, mounted ''Homare'' 12, and fitted 2 × 13 mm (.51 in) Type 2 machine guns in the back defensive position. ;;P1Y1c ''Provisional name Ginga Model 11C'' (仮称銀河11丙型, ''Kashō Ginga 11 Hei-gata'') : Converted from P1Y1b, mounted ''Homare'' 12, and fitted 1 × 13 mm (.51 in) Type 2 machine gun in the forward position, prototype only. ;;P1Y1 ''Ginga Model 11'' Night-fighter variant (銀河11型改造夜戦, ''Ginga 11-gata Kaizō yasen'') : Converted from P1Y1. Armed with 2 × 20 mm Type 99 cannons. Equipped 302nd Kōkūtai only. This is not a naval regulation equipment. ;;P1Y1-S ''Provisional name Ginga Model 21'' (仮称銀河21型, ''Kashō Ginga 21-gata'') : Night fighter variant. Armed with 4 × 20 mm Type 99 cannons firing obliquely forward, and 1 × 13 mm (.51 in) Type 2 machine gun in the back defensive position. Only a project. ;;P1Y1 Ground attack variant : Converted from P1Y1/P1Y1a, installed up to 20 × 20 mm Type 99 cannons in the bomb bay for land strikes against B-29 bases in the Marianas. Approx. 30 rebuilt. ;P1Y2-S ''Provisional name Ginga Model 26/Test production Kyokkō'' ("

Aurora An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of bri ...

") (仮称銀河26型/試製極光, ''Kashō Ginga 26-gata''/''Shisei Kyokkō'') : Night fighter variant. Initial named ''Hakkō'' ("

Corona Corona (from the Latin for 'crown') most commonly refers to: * Stellar corona, the outer atmosphere of the Sun or another star * Corona (beer), a Mexican beer * Corona, informal term for the coronavirus SARS-CoV-2, which causes the COVID-19 di ...

", 白光) in October 1943, renamed ''Kyokkō'' in March 1944.Model Art (2001), p. 50–53 Converted from P1Y1/P1Y1a. Fitted Mitsubishi MK4T-A Kasei 25 engines. Armed with 2 × 20 mm Type 99 cannons and 1 × 30 mm

Type 5 cannon The 30 mm Type 5 cannon was a Japanese Navy autocannon used near the end of World War II. It was an indigenous 30 mm design with better performance than the Navy's earlier Oerlikon-derived Type 2 or the Imperial Army's Browning-derived Ho-155, al ...

. Later, almost all were converted to P1Y2. 96 or 97 produced.Famous Airplanes of the World (2000), p. 31 ;;P1Y2 ''Provisional name Ginga Model 16'' (仮称銀河16型, ''Kashō Ginga 16-gata'') : Land based bomber. Converted from P1Y2-S. Mounted 1,380 kW (1,850 hp) Mitsubishi MK4T-A Kasei 25 Kō engines. ;;P1Y2a ''Provisional name Ginga Model 16A'' (仮称銀河16甲型, ''Kashō Ginga 16 Kō-gata'') : Converted from P1Y1a. Mounted Mitsubishi MK4T-A Kasei 25 Kō engines. ;;P1Y2b ''Provisional name Ginga Model 16B'' (仮称銀河16乙型, ''Kashō Ginga 16 Otsu-gata'') : Converted from P1Y1b. Mounted Mitsubishi MK4T-A Kasei 25 Kō engines. ;;P1Y2c ''Provisional name Ginga Model 16C'' (仮称銀河16丙型, ''Kashō Ginga 16 Hei-gata'') : Converted from P1Y1c. Mounted Mitsubishi MK4T-A Kasei 25 Kō engines. ;;P1Y2 ''Ginga Model 16'' Night-fighter variant (銀河16型改造夜戦, ''Ginga 16-gata Kaizō yasen'') : Converted from P1Y2. Armed with 2 × 20 mm Type 99 machine guns or 1 × 30 mm Type 5 cannon. Equipped 302nd Kōkūtai only. This is not a naval regulation equipment. ;P1Y3 ''Provisional name Ginga Model 13'' (仮称銀河13型, ''Kashō Ginga 13-gata'') : Converted from P1Y1. Mounted ''Homare'' 21 engines. ;P1Y4 ''Provisional name Ginga Model 12'' (仮称銀河12型, ''Kashō Ginga 12-gata'') : Converted from P1Y1. Mounted ''Homare'' 23 engines. ;P1Y5 ''Provisional name Ginga Model 14'' (仮称銀河14型, ''Kashō Ginga 14-gata'') : Converted from P1Y1. Mounted Mitsubishi Ha-43 engines. ;P1Y6 ''Provisional name Ginga Model 17'' (仮称銀河17型, ''Kashō Ginga 17-gata'') : Converted from P1Y2. Mounted Mitsubishi MK4T-C Kasei 25 Hei engines. ;''Provisional name Ginga Model 33'' (仮称銀河33型, ''Kashō Ginga 33-gata'') : Long-range bomber variant. Crew: 4, bombs= up to 3,000 kg. Only a project. ; ''Test production Tenga'' (試製天河, ''Shisei Tenga'') :Proposed jet-powered bomber variant, mounted Ishikawajima Ne-30. Discontinued in 1945. ;MXY10 Yokosuka Navy Bomber ''Ginga'' : Ground decoy non-flying replica of Yokosuka P1Y1.

Number built by Nakajima and Kawanishi

Operators

; *

Imperial Japanese Navy Air Service The was the air arm of the Imperial Japanese Navy (IJN). The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War. The Japanese military acquired their first aircraft in 1910 ...

The Maru Mechanic (1984), p. 110Model Art (1993), p. 135Famous Airplanes of the World (2000), p. 32–38 ** 302nd Kōkūtai: Equipped night fighter variant only. ** 521st Kōkūtai ** 522nd Kōkūtai ** 523rd Kōkūtai ** 524th Kōkūtai ** 701st Kōkūtai ** 706th Kōkūtai ** 752nd Kōkūtai ** 761st Kōkūtai ** 762nd Kōkūtai ** 763rd Kōkūtai ** 765th Kōkūtai ** 1001st Kōkūtai ** 1081st Kōkūtai ** Miyazaki Kōkūtai ** Toyohashi Kōkūtai ** Yokosuka Kōkūtai ** Kogeki 262nd Hikōtai ** Kogeki 401st Hikōtai ** Kogeki 405th Hikōtai ** Kogeki 406th Hikōtai ** Kogeki 501st Hikōtai ** Kogeki 708th Hikōtai

Specifications (P1Y1a)

References

Notes

Bibliography

* *

Design and development

Operational history

Survivors

Variants

Number built by Nakajima and Kawanishi

Operators

Specifications (P1Y1a)

See also

References

Notes

Bibliography

Further reading