Military Factory logo

Nakajima B5N (Kate)

Imperial Japan (1941)
Picture of Nakajima B5N (Kate) Carrier-Borne Torpedo Bomber

By the time of World War 2, the Nakajima B5N of the Imperial Japanese Navy was regarded as the best carrier-borne torpedo bomber anywhere in the world.


Detailing the development and operational history of the Nakajima B5N (Kate) Carrier-Borne Torpedo Bomber.  Entry last updated on 5/10/2016. Authored by Staff Writer. Content ©www.MilitaryFactory.com

The Nakajima B5N series of torpedo bombers originating from Japan were considered the best of their type anywhere in the world by the time of the American entry into the conflict during late-1941. The aircraft saw development against an Imperial Japanese Navy (IJN) requirement in 1935 and a first-flight followed in January of 1937. It was in operational service at the outbreak of World War 2 (1939-1945) and was one of the more crucial and effective aircraft deployed by the Japanese Navy in its various attacks - including the assault on Pearl Harbor, Hawaii in December of 1941. The B5N was produced across 1,149 examples and saw service through most of the global conflict.

The aircraft's general arrangement was conventional for the period and fitted the single air-cooled radial engine in the nose. The wing mainplanes were low-mounted along the fuselage sides and fitted slight ahead of midships. The tail used a single vertical plane with two low-mounted horizontal planes. The crew of three - pilot, bombardier-navigator, and rear machine gunner - were seated in line under a long-running "greenhouse-style" canopy. The main legs of the undercarriage were retractable and the tail wheel stayed exposed during flight.

The B5N was powered by a single in-house Nakajima radial piston engine - B5N1 models were given "Hikari" radials while B5N2s carried "Sakae 11" radials of 1,000. The B5N2 managed a maximum speed of 235 miles-per-hour, ranged out to 1,240 miles, and could reach a service ceiling of 27,100 feet.

Armament consisted of a single 7.7mm Type 92 machine gun set on a trainable mounting at the rear gunner's position. Some B5N1 models were equipped with 2 x 7.7mm Type 97 machine guns in the wings for a broader frontal "punch". For offensive work, the aircraft was cleared to carry a single Type 91 torpedo of 1,760lb or, in its place, 2 x 550lb bombs along with 6 x 295lb bombs for conventional bombing sorties.

The initial B5N form became the "Type K" prototype of 1937 and this was followed in 1938 by combat-quality B5N1 production models. The B5N1-K designation was used to signify B5N1s converted for the training role. The improved B5N2 - with more powerful Sakae engines and smaller cowlings - appeared in 1939 and marked the final production form.

Initial combat actions placed the B5N over China and these were used both as carrier-based attackers and land-based warplanes. The aircraft was quick to earn the respect of the world with its striking ability and accuracy and made up a portion of the Japanese attack force used at Pearl Harbor on December 7th, 1941. At least 144 B5N2 aircraft took part in the assault. The aircraft would find future successes at Coral Sea, Midway, and over the Santa Cruz Islands in the campaigns that followed - destroying many Allied vessels across the Pacific Theater and credited with the sinking of the important American aircraft carriers USS Hornet, USS Lexington, and the USS Yorktown.

Once Allied pilots became combat-tested and handed much improved fighters, the B5N's inherent deficiencies shown through - they were weakly-armed defensively, poorly protected overall, and suffered from weight issues when carrying their potent war loads. This meant that those unlocky enough to find themselves in the crosshairs of Allied gunners could very easily fall prey. As such, losses began to mount and the last major engagements involving B5N aircraft were recorded over the Philippine Islands during 1944. The series was being phased out towards the end of the war but active aircraft - due to their still-excellent operational ranges - were used in non-direct-combat roles such as anti-ship, reconnaissance, and maritime patrol sorties. Some were featured as Kamikaze attackers leading up to the war's final months.

The Nakajma B6N "Jill" (detailed elsewhere on this site) became the B5N's direct successor and appeared in August of 1943. It was produced to the tune of 1,268 examples and managed its own wartime combat record.

Any available statistics for the Nakajima B5N (Kate) Carrier-Borne Torpedo Bomber are showcased in the areas immediately below. Categories include basic specifications covering country-of-origin, operational status, manufacture(s) and total quantitative production. Other qualities showcased are related to structural values (namely dimensions), installed power and standard day performance figures, installed or proposed armament and mission equipment (if any), global users (from A-to-Z) and series model variants (if any).






Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

Image of collection of graph types

Relative Maximum Speed Rating
Hi: 300mph
Lo: 150mph
    This entry's maximum listed speed (235mph).

    Graph average of 225 miles-per-hour.
Relative Operational Ranges
NYC
 
  LON
LON
 
  PAR
PAR
 
  BER
BER
 
  MOS
MOS
 
  TOK
TOK
 
  SYD
SYD
 
  LAX
LAX
 
  NYC
Graph showcases the Nakajima B5N2 (Kate)'s operational range (on internal fuel) when compared to distances between major cities.
Aviation Era Impact
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
1149
1149


  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.


Altitude Visualization
Small airplane graphic
  Compare this entry against other aircraft using our Comparison Tool  
Supported Mission Types:
Air-to-Air
Interception
Unmanned
Ground Attack
Close-Air Support
Training
Anti-Submarine
Anti-Ship
Airborne Early Warning
MEDEVAC
Electronic Warfare
Maritime/Navy
Aerial Tanker
Utility/Transport
Passenger Industry
VIP Travel
Business Travel
Search/Rescue
Recon/Scouting
Special Forces
X-Plane/Development
National Flag Graphic
National Origin: Imperial Japan
Service Year: 1941
Classification Type: Carrier-Borne Torpedo Bomber
Manufacturer(s): Nakajima - Imperial Japan
Production Units: 1,149
Global Operators:
Imperial Japan
Structural - Crew, Dimensions, and Weights:
Unless otherwise noted the presented statistics below pertain to the Nakajima B5N2 (Kate) model. Common measurements, and their respective conversions, are shown when possible.

Operational
CREW


Personnel
3


Dimension
LENGTH


Feet
33.79 ft


Meters
10.3 m


Dimension
WIDTH


Feet
50.92 ft


Meters
15.52 m


Dimension
HEIGHT


Feet
12.14 ft


Meters
3.7 m


Weight
EMPTY


Pounds
5,024 lb


Kilograms
2,279 kg


Weight
LOADED


Pounds
9,039 lb


Kilograms
4,100 kg

Installed Power - Standard Day Performance:
1 x Nakajima NK1B Sakae 11 radial piston engine developing 1,000 horsepower.

Performance
SPEED


Miles-per-Hour
235 mph


Kilometers-per-Hour
378 kph


Knots
204 kts


Performance
RANGE


Miles
1,237 mi


Kilometers
1,990 km


Nautical Miles
1,075 nm


Performance
CEILING


Feet
27,100 ft


Meters
8,260 m


Miles
5.13 mi


Performance
CLIMB RATE


Feet-per-Minute
1,230 ft/min


Meters-per-Minute
375 m/min

Armament - Hardpoints (1):

STANDARD:
1 x 7.7mm Type 92 machine gun in trainable position at rear cockpit.
2 x 7.7mm Type 97 machine guns in wings (some B5N1 models).

OPTIONAL:
1 x 1,760 lb torpedo OR 2 x 550lb bombs with 6 x 295lb bombs.
Visual Armory:

Graphical image of an aircraft medium machine gun
Graphical image of an aircraft aerial torpedo
Graphical image of an aircraft conventional drop bomb munition
Variants: Series Model Variants
• B5N - Base Model Series Designation
• Type K - Prototype Designation
• B5N1 - Initial Production Model
• B5N1-K - B5N1 aircraft converted for the training role.
• B5N2 - Improved B5N1 with Sakae 11 radial engine and revised engine cowling.