Nakajima B5N

Japanese attack aircraft family

B5N

A Nakajima B5N2 "Kate" in flight

General information
Type| Carrier-based torpedo bomber/high-level bomber
National origin| Japan
Manufacturer| Nakajima Aircraft Company
Status| Retired
Primary user| Imperial Japanese Navy Air Service
Number built| 1,149[1]
History
First flight| January 1937
Retired| 1945

The Nakajima B5N (Japanese: 中島 B5N, Allied reporting name "Kate") was the standard carrier-based torpedo bomber of the Imperial Japanese Navy (IJN) for much of World War II. It also served as a high level bomber.

Although the B5N was substantially faster and more capable than its Allied counterparts, the American Douglas TBD Devastator monoplane (the U.S. Navy's first all-metal, carrier-borne monoplane of any type with retracting gear), and the British Fairey Swordfish and Fairey Albacore torpedo biplanes, it was nearing obsolescence by 1941. Nevertheless, the B5N operated throughout the whole war, due to the delayed development of its successor, the B6N.

In the early part of the Pacific War, when flown by well-trained IJN aircrews and as part of well-coordinated attacks, the B5N achieved particular successes at the battles of Pearl Harbor, Coral Sea, Midway, and Santa Cruz Islands.[2][3]

## Design and development

[edit]

The B5N was designed by a team led by Katsuji Nakamura in response to a 1935 specification by the Navy for a torpedo bomber to replace the Yokosuka B4Y. Internally designated Type K by Nakajima, it successfully competed with the Mitsubishi B5M for a production contract. The first prototype flew in January 1937 and was ordered into production soon afterwards with the full designation Type 97 Carrier Attack Bomber[4] (九七式艦上攻撃機) (kyū-nana-shiki kanjō kōgeki-ki or kankō for short).[5]

Combat experience during the Second Sino-Japanese War revealed several weaknesses in the original B5N1 production model. These were mainly concerned with the lack of protection that the design offered its crew and its fuel tanks. Keen to maintain the high performance of the type, the Navy was reluctant to add weight in the form of armor, and instead looked to obtaining a faster version of the aircraft in the hopes of outrunning enemy fighters. The B5N2 was given a much more powerful engine - Nakajima's own Sakae Model 11, 14-cylinder twin-row radial, as used in the initial models of the Mitsubishi A6M fighter – and various modifications were made to streamline it. Although its performance was only marginally better, and its weaknesses remained unremedied, this version replaced the B5N1 in production and service from 1939.

## Equipment

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Type 88 bombsight, torpedo release lever, and manual bomb release from a Nakajima B5N2 "Kate" at the Pearl Harbor Aviation Museum

The navigator/bombardier/observer position was equipped with a Type 90 bombsight, which was a long vertical tube located in the front-left of the seat. There was also a Type 3 reflector compass for precise navigation that was mounted on the top of the cockpit frame. The radio-operator/gunner position was equipped with one of the standard-issue radio sets for navy three-seater aircraft (Type 96 Mk3 earlier and Type 2 Mk3 later) that was mounted in front of the radio-operator/gunner's seat and behind the navigator/bombardier/observer's seat.[6][7]

The radio-operator/gunner also operated one flexible 7.7 mm (.303 in) Type 92 machine gun at the rear end of the cockpit. One Type 91 torpedo could be mounted on the racks that were fixed eccentrically to the right at the bottom of the fuselage. Alternatively, racks could be replaced to carry either one 800 kg bomb (e.g., Type 99 No 80 armor-piercing bomb) or two 250 kg bombs (e.g., Type 98 No 25 land bomb) or six 60 kg bombs (e.g., Type 2 No 6 land bomb). Replacing the racks and exchanging between the torpedo and bombs was not a trivial process and could take more than two hours to complete.[8]

Initially, most of the B5N bombers were painted in silver, which was the color used throughout the early stages of the Second Sino-Japanese War. The color eventually changed to dark green before the start of the Pacific War.[9]

## Operational history

[edit]

A captured Nakajima B5N2 "Kate" being flown over Maryland, 1943 A crashed Nakajima B5N2 "Kate" (tail marking "EI-306") from Shōkaku A B5N1 "Kate" parked in front of a hangar

The B5N was primarily employed as a carrier-based aircraft and occasionally as a land-based bomber. It carried a crew of three: pilot, navigator/bombardier/observer, and radio-operator/gunner.[10] As with other IJN multi-seat aircraft, an individual bomber was commanded by the senior ranking crew member aboard, which could be the observer rather than the pilot.[11]

The initial model B5N1 first saw action in the Second Sino-Japanese War in 1938. The updated B5N2 played a major role in the Attack on Pearl Harbor. One of the B5N2s carried Mitsuo Fuchida, the commander of the attack, with one high-level bomber from the carrier Hiryū credited with sinking the American battleship Arizona. The B5N2 torpedo bombers also sank the battleships West Virginia, California, Oklahoma and Utah. Five torpedo bombers were shot down in the first wave. Apart from this raid, the greatest successes of the B5N2 were the key roles it played in sinking the United States Navy aircraft carrier Lexington at the Battle of the Coral Sea and the aircraft carrier Hornet at the Battle of the Santa Cruz Islands, and the disabling of the aircraft carrier Yorktown at the Battle of Midway, later sunk by the Japanese submarine I-168.[2][3]

B5N2 torpedo bombers normally performed a coordinated attack on enemy carriers with Aichi D3A dive bombers. Ideally, dive bombers would help to suppress the ship's anti-aircraft fire, which improved the chances of success for the slow-flying torpedo bombers.[11] During the Battle of the Eastern Solomons, the IJN tried to minimize losses to torpedo bombers and initially sent only the dive bombers to attack and cripple US carriers for the subsequent torpedo strike, this proved unsuccessful, as the torpedo bombers did not launch until the battle was over.[12]

The B5N served as the basis for a follow-on design, the B6N, which eventually replaced it in front-line service. The B5N continued to fly in secondary roles, such as training, target towing, and anti-submarine warfare. Some of the aircraft used for this latter purpose were equipped with early radars and magnetic anomaly detectors. B5Ns were also used as bombers during the unsuccessful defense of the Philippines in October 1944, suffering severe losses. Later in the war, they were used for kamikaze attacks.

## Variants

[edit]

* Type K: Prototype.
* B5N1: First production model.
* B5N1-K: Many B5N1s were converted into advanced training aircraft.
* B5N2: Improved version.

## Operators

[edit]

Japan

* Imperial Japanese Navy

## Surviving aircraft

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Nakajima B5N2 "Kate" reconstruction at the Pearl Harbor Aviation Museum in 2019. The original Hinomaru is still visible on the starboard wing underside.

None of the 1,150 production B5Ns survived World War II intact. Only two partially-recovered B5Ns are known to exist, neither of them airworthy.

Replicas of the B5N2s were made using stretched fuselages from U.S. Canadian Car and Foundry "Harvard" - a variant of the North American T-6 Texan trainers, which were modified to represent Japanese aircraft for the movie Tora! Tora! Tora!, and have been used in a number of movies and airshows since to depict the aircraft.

One recovered B5N2 is at the Wings Museum in Balcombe, West Sussex, UK.[13] This large portion was recovered from the Kuril Islands by a British private collector in 2003.[citation needed]

A B5N was unveiled at the Pacific Aviation Museum in Honolulu, Hawaii on 18 April 2016.[14]

## Specifications (Nakajima B5N2)

[edit]

Nakajima B5N1

Data from Japanese Aircraft of the Pacific War [15]

General characteristics

* Crew: 3
* Length: 10.3 m (33 ft 10 in)
* Wingspan: 15.518 m (50 ft 11 in)
* Height: 3.7 m (12 ft 2 in)
* Wing area: 37.7 m2 (406 sq ft)
* Airfoil: root: NN-5 mod (16%); tip: NN-5 mod (8%)[16]
* Empty weight: 2,279 kg (5,024 lb)
* Gross weight: 3,800 kg (8,378 lb)
* Max takeoff weight: 4,100 kg (9,039 lb)
* Powerplant: 1 × Nakajima Sakae 11 14-cylinder air-cooled radial piston engine, 750 kW (1,000 hp) for take-off

720 kW (970 hp) at 3,000 m (9,800 ft)

* Propellers: 3-bladed constant-speed metal propeller

Performance

* Maximum speed: 378 km/h (235 mph, 204 kn) at 3,600 m (11,800 ft)
* Cruise speed: 259 km/h (161 mph, 140 kn) at 3,000 m (9,800 ft)
* Range: 978 km (608 mi, 528 nmi)
* Ferry range: 1,991 km (1,237 mi, 1,075 nmi)
* Service ceiling: 8,260 m (27,100 ft)
* Rate of climb: 6.5 m/s (1,280 ft/min)
* Time to altitude: 3,000 m (9,800 ft) in 7 minutes 40 seconds
* Wing loading: 100.8 kg/m2 (20.6 lb/sq ft)
* Power/mass: 0.196 kW/kg (0.119 hp/lb)

Armament

* Guns: 1 × 7.7 mm Type 92 machine gun 'Ru' (Lewis) in rear dorsal position, fed by hand loaded drum magazines of 97 rounds. A number of B5N1s were equipped with 2 × 7.7 Type 97 machine guns in the wings.
* Bombs: 1 × 800 kg (1,760 lb) Type 91 torpedo or 1 × 800 kg (1,760 lb) bomb or 2 × 250 kg (550 lb) bombs or 6 × 60 kg (132 lb) bombs[17]

## See also

[edit]

* Nakajima B6N

Aircraft of comparable role, configuration, and era

* Douglas TBD Devastator
* Fairey Barracuda
* Mitsubishi B5M

Related lists

* List of aircraft of World War II
* List of military aircraft of Japan

## References

[edit]

### Notes

[edit]

1. ^ Angelucci, Enzo (1988). Combat aircraft of World War II. p. 18\. ISBN 0-517-64179-8.
2. ^ a b Lundstrom 2005a.
3. ^ a b Lundstrom 2005b.
4. ^ Francillon 1970, pp. 412–413
5. ^ Parshall & Tully 2007, p. 80
6. ^ Mikesh 2004.
7. ^ Tagaya 2003.
8. ^ Chambers 2017, p. 43.
9. ^ Chambers 2017, p. 11.
10. ^ Chambers 2017, p. 8.
11. ^ a b Tagaya 2011.
12. ^ Chambers 2017, p. 67.
13. ^ "Ghosts of the Tundra". Wings Museum. 28 September 2015. Retrieved 24 April 2022.
14. ^ "Nakajima B5N2 'Kate' Unveiled at Pacific Aviation Museum Pearl Harbor". Warbirds News. 21 April 2016. Retrieved 29 April 2016.
15. ^ Francillon 1970, p. 416
16. ^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.
17. ^ Wieliczko, Leszek (in Polish). Nakajima B5N (Kate). „Lotnictwo” No. 5/2018(199), p. 87.

### Bibliography

[edit]

* Angelucci, Enzo and Paolo Matricardi. World Aircraft: World War II, Volume II (Sampson Low Guides). Maidenhead, UK: Sampson Low, 1978. ISBN 0-562-00096-8.
* Chambers, Mark A. (2017). Nakajima B5N 'Kate' and B6N 'Jill' Units. Vol. Combat Aircraft #119. Osprey Publishing. ISBN 978-1472818744.
* Francillon, René J. (1970). Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd. ISBN 0-370-30251-6.
* Francillon, René J. Japanese Bombers of World War Two, Volume One. Windsor, Berkshire, UK: Hylton Lacy Publishers Ltd., 1969. ISBN 0-85064-022-9.
* Lundstrom, John B. (2005a). The First Team: Pacific Naval Air Combat from Pearl Harbor to Midway (New ed.). Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-471-X.
* Lundstrom, John B. (2005b). First Team and the Guadalcanal Campaign: Naval Fighter Combat from August to November 1942 (New ed.). Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-472-8.
* Mikesh, Robert C. (2004). Japanese Aircraft Equipment: 1940-1945. Schiffer Publishing. ISBN 0764320971..
* Parshall, Jonathan; Tully, Anthony (2007). Shattered Sword: The Untold Story of the Battle of Midway. Washington D.C.: Potomac Books Inc. ISBN 978-1-57488-924-6.
* Tagaya, Osamu (2003). Imperial Japanese Naval Aviator 1937-45. Osprey Publishing. ISBN 1841763853.
* Tagaya, Osamu (2011). Aichi 99 Kanbaku 'Val' Units of World War 2. Botley, UK: Osprey Publications. ISBN 978-1-84176-912-7.

## External links

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Wikimedia Commons has media related to Nakajima B5N.

* https://www.pearlharboraviationmuseum.org/pearl-harbor-blog/nakajima-b5n2/ Archived 2018-12-04 at the Wayback Machine
* Nakajima B5N, Joao Paulo Julião Matsuura
* Pictorial of B5N in multiplayer air-combat simulation of Battle of Coral Sea.

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Nakajima aircraft

Imperial Japanese Navy types|

| Carrier fighters|

* A1N
* A2N
* A3N
* A4N

|

Carrier Torpedo Bombers|

* B3N
* B4N
* B5N
* B6N

Reconnaissance aircraft|

* C2N
* C3N
* C6N

Dive bombers|

* D3N

Reconnaissance floatplanes|

* E2N
* E4N
* E8N

Land-based Attack Bombers|

* G5N
* G8N
* G10N

Interceptors|

* J1N
* J5N
* Nakajima Kikka

Transports|

* L1N

Floatplane fighter|

* A6M2-N

Other|

* LB-2
* P-1

Imperial Japanese Army types|

| Army manufacturer type code system|

* Nieuport 83/Nakajima 甲2 (Ko 2)
* Nieuport 24/Nakajima 甲3 (Ko 3)
* Nieuport-Delage NiD 29/Nakajima 甲4 (Ko 4)

|

Army type-year|

* Type 91 fighter
* Type 94 reconnaissance aircraft
* Type 95 training aircraft
* Type 97 fighter
* Type 97 transport
* Type 100 heavy bomber
* Type 1 fighter
* Type 2 single-seat fighter
* Type 4 fighter

Kitai (airframe #)|

* Ki-4
* Ki-6
* Ki-8
* Ki-11
* Ki-12
* Ki-13
* Ki-16
* Ki-19
* Ki-27
* Ki-31
* Ki-34
* Ki-37
* Ki-41
* Ki-43
* Ki-44
* Ki-49
* Ki-52
* Ki-53
* Ki-58
* Ki-62
* Ki-63
* Ki-68
* Ki-75
* Ki-80
* Ki-82
* Ki-84
* Ki-87
* Ki-101
* Ki-106
* Ki-113
* Ki-115
* Ki-201
* Ki-230

WW2 Allied reporting names|

* Abdul
* Bob
* Dave
* Frank
* Helen
* Irving
* Jill
* Jim
* Kate
* Liz
* Myrt
* Clint
* Nate
* Oscar
* Rita
* Rufe
* Thora
* Tojo

* v
* t
* e

Hiro Naval Arsenal

Aircraft designed and produced by Hiro|

* H1H
* H2H
* H4H
* G2H

Prototypes and experimental aircraft|

* R-3
* H3H1
* H10H

Aircraft designed by others produced at Hiro|

* Kugisho B3Y
* Nakajima B5N "Kate"
* Aichi E13A "Jake"
* Yokosuka D4Y "Judy"

Engines designed and produced by Hiro|

* Type 14
* Type 61
* Type 91
* Type 94

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Imperial Japanese Navy aircraft designations (short system)

Fighters (A)|

* Nakajima A1N
* Nakajima A2N
* Nakajima A2N
* Nakajima A4N
* Mitsubishi A5M
* Mitsubishi A6M Zero
* A7He
* Mitsubishi A7M
* Seversky A8V

* AXB1
* AXD1
* AXG1
* AXH1
* AXHe1
* AXV1

Torpedo bombers (B)|

* Mitsubishi B1M
* Mitsubishi B2M
* Nakajima B3N
* Kugisho B3Y
* Mitsubishi B4M
* Nakajima B4N
* Yokosuka B4Y
* Mitsubishi B5M
* Nakajima B5N
* Nakajima B6N
* Aichi B7A

* BXN1

* C6N1-B2

Shipboard reconnaissance (C)|

* Mitsubishi C1M
* Nakajima C2N
* Nakajima C3N
* Aichi C4A
* Mitsubishi C5M
* Nakajima C6N

* CXP1

* Yokosuka D4Y1-C2
* Nakajima E4N2-C2

Dive bombers (D)|

* Aichi D1A
* Nakajima D2N
* Yokosuka D2Y
* Aichi D3A
* Mitsubishi D3M
* Nakajima D3N
* Yokosuka D3Y
* Yokosuka D4Y

* DXD1
* DXHe1

Reconnaissance seaplanes (E)|

* Yokosuka E1Y
* Nakajima E2N
* Aichi E3A
* Nakajima E4N
* Kawanishi E5K
* Yokosuka E5Y
* Yokosuka E6Y
* Kawanishi E7K
* Aichi E8A
* Kawanishi E8K
* Nakajima E8N
* Watanabe E9W
* Aichi E10A
* Kawanishi E10K
* Aichi E11A
* Kawanishi E11K
* Aichi E12A
* Kawanishi E12K
* Nakajima E12N
* Aichi E13A
* Kawanishi E13K
* Watanabe E14W
* Yokosuka E14Y
* Kawanishi E15K
* Aichi E16A

Observation seaplanes (F)|

* Aichi F1A
* Mitsubishi F1M

* J1N1-F2

Land-based bombers (G)|

* Mitsubishi G1M (I)
* Mitsubishi G1M (II)
* Hiro G2H
* Mitsubishi G3M
* Mitsubishi G4M
* Nakajima G5N
* Mitsubishi G4M
* Mitsubishi G7M
* Nakajima G8N
* Kawanishi G9K
* Nakajima G10N

Flying Boats (H)|

* Hiro H1H
* Hiro H2H
* Hiro H3H
* Kawanishi H3K
* Hiro H4H
* Yokosuka H5Y
* Kawanishi H6K
* Yokosuka H7Y
* Kawanishi H8K
* Aichi H9A
* Hiro H10H
* Kawanishi H11K

* HXC1
* HXD1
* HXP1

Land-based Fighters (J)|

* Nakajima J1N
* Mitsubishi J2M
* Kawanishi J3K
* Mitsubishi J4M
* Nakajima J5N
* Kawanishi J6K
* Kyushu J7W
* Mitsubishi J8M
* Nakajima J9N3

* N1K1-J/N1K2-J2

Trainers (K)|

* Yokosuka K1Y
* Yokosuka K2Y
* Mitsubishi K3M
* Yokosuka K4Y
* Yokosuka K5Y
* Kawanishi K6K
* Mitsubishi K6M
* Watanabe K6W
* Mitsubishi K7M
* Kawanishi K8K
* Nippi K8Ni
* Nihon K8P
* Watanabe K8W
* Kyushu K9W
* Kyushu K10W
* Kyushu K11W

* KXA1
* KXBu1
* KXC1
* KXJ1
* KXHe1
* KXL1
* A5M4-K2
* A6M2-K2
* B5N1-K2
* D3Y1-K2
* E13A1-K2
* F1M2-K2
* G6M1-K2
* M6A1-K2
* Q1W1-K2

Transports (L)|

* Nakajima L1N
* Showa/Nakajima L2D
* Mitsubishi L3Y
* Mitsubishi L4M
* Nihon L7P

* LXC1
* LXD1
* LXF1
* LXG (KR-2)1
* LXG (G-21)1
* LXHe1
* LXJ (Ju 60)1
* LXJ (Ju 86)1
* LXK1
* LXM1

* G5N2-L2
* G6M1-L2
* H6K2-L/H6K4-L2
* H8K1-L/H8K2-L/H8K4-L2
* H11K1-L2
* K3M3-L2

Special-purpose (M)1|

* Aichi M6A

* Nihon MXJ1
* Yokosuka MXY1
* Yokosuka MXY2
* Yokosuka MXY3
* Yokosuka MXY4
* Yokosuka MXY5
* Yokosuka MXY6
* Yokosuka MXY7
* Yokosuka MXY8
* Yokosuka MXY9
* Yokosuka MXY10
* Yokosuka MXY11
* Mizuno MXZ1

Floatplane fighters (N)|

* Kawanishi N1K

* Nakajima A6M2-N2

Land-based bombers (P)|

* Yokosuka P1Y
* Mitsubishi P2M

Patrol (Q)|

* Kyushu Q1W
* Mitsubishi Q2M
* Kyushu Q3W

Land-based reconnaissance (R)|

* Yokosuka R1Y
* Yokosuka R2Y

* Yokosuka D4Y2-R2
* Nakajima J1N1-R2

Night fighters (S)|

* Aichi S1A

* Nakajima C6N1-S2
* Yokosuka D4Y2-S2
* Aichi E13A1a-S/E13A1b-S2
* Nakajima J1N1-S2
* Yokosuka P1Y1-S/P1Y2-S2

1 X as second letter is for experimental aircraft or imported technology demonstrators not intended for service, 2 Hyphenated trailing letter (-J, -K, -L, -N or -S) denotes design modified for secondary role, 3 Possibly incorrect designation, but used in many sources

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World War II Allied reporting names for Japanese aircraft

Aircraft in Japanese service|

* Abdul
* Alf
* Ann
* Babs
* Baka
* Belle
* Betty
* Bob
* Buzzard
* Cedar
* Cherry
* Clara
* Claude
* Cypress
* Dave
* Dick
* Dinah
* Dot
* Edna
* Emily
* Eva
* Eve
* Frances
* Frank
* Gander
* George
* Glen
* Goose
* Grace
* Gwen
* Hamp
* Hank
* Hap
* Helen
* Hickory
* Ida (Ki-36)
* Ida (Ki-55)
* Irving
* Jack
* Jake
* Jane
* Jean
* Jerry
* Jill
* Jim
* Judy
* Kate
* Kate 61
* Laura
* Lily
* Liz
* Lorna
* Loise
* Louise
* Luke
* Mabel
* Mary
* Mavis
* Myrt
* Nate
* Nell
* Nick
* Norm
* Oak
* Oscar
* Pat
* Patsy
* Paul
* Peggy
* Perry
* Pete
* Pine
* Rex
* Rita
* Rob
* Rufe
* Ruth
* Sally
* Sally III
* Sam
* Sandy
* Slim
* Sonia
* Spruce
* Stella
* Steve
* Susie
* Tabby
* Tess
* Thalia
* Thelma
* Theresa
* Thora
* Tina
* Tillie
* Toby
* Tojo
* Tony
* Topsy
* Val
* Willow
* Zeke
* Zeke 32

Foreign aircraft
thought to be in Japanese service|

* Bess (Heinkel He 111)
* Doc (Messerschmitt Bf 110)
* Fred (Focke Wulf Fw 190)
* Irene (Junkers Ju 87)
* Janice (Junkers Ju 88)
* Mike (Messerschmitt Bf 109)
* Millie (Vultee V-11)
* Trixie (Junkers Ju 52)
* Trudy (Focke-Wulf Fw 200)

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