World War II Vehicles, Tanks and Airplanes, picture of P-51 Mustang
World War II Vehicles, Tanks and Airplanes, picture of T-34/85
World War II Vehicles, Tanks and Airplanes, picture of Fw-190
World War II Vehicles, Tanks and Airplanes, picture of Churchill
wwiivehicles.com ©2017
Search:
Japan's Imperial Navy flag

Japan's Yokosuka D4Y Suisei ("comet") dive bomber
Navy Type 2
Allied Code Name: Judy

Design

The design for the Yokosuka D4Y was based on the purchased design of the German He 118 (DXHe1).

When the original He 118V4 was destroyed, the Imperial Japanese Navy as the Dai-Ichi Kaigun Koku Gijitsusho (First Technical Arsenal of Naval Aviation) in Yokosuka to design a replacement following the design of the He 118.

The requirements of the D4Y were:

  • Cruising Speed: 265 mph
  • Speed: 322 mph
  • Range with 551 lb / 250 kg bombs: 921 miles
  • Range with no bombs: 1,381 miles
  • Operate from small carriers

Chief Engineer Masao Yamana headed the design team. The D4Y design was smaller and lighter than the He 118.

The D4Y was supposed to replace the Aichi D3A but it wasn't well armed and the engines were unreliable.

Armament

The D4Y carried its bomb load internally.

Construction

The construction of the D4Y was all metal.

Crew

There was no armor protection for the crew or fuel tanks.

Engine

The engine was based on an imported Daimler-Benz DB 600G engine. Initially there were problems with the Aichi Atsuta model, the DB 601A, and this delayed the D4Y.

The D4Y was one of two mass produced aircraft that used liquid cooled engines in the Japanese military, the Ki-61 Hien being the other.

The engines were the D4Y's Achilles heel.

Wings

The wing span was made short enough to not need to be folded on carriers.

There were three electric powered dive brakes in each wing.

Prototype

The He 118 was flown at Yokosuka. The Imperial Japanese Navy was impressed with its performance but it fell apart in a test flight.

The D4Y1 prototype was finished in November 1940.

The D4Y1 prototype first flew in December 1940 / 1941. The wings had a flutter and the wing spars started to crack during dive bombing tests.

Production

Aichi's Nagoya plant produced the D4Y1-C. 660 were delivered by the spring of 1942.

The D4Y3 was test flown in May 1944.

  • Prototypes: 5
    • Manufacturer: Dai-Ichi Kaigun Koku Gijitsusho at Yokosuka
    • Production: 1940 - 1941
  • Yokosuka D4Y: 2,033
  • Yokosuka D4Y1:
    • Manufacturer: Dai-Ichi Kaigun Koku Gijitsusho (11th Naval Air Arsenal) at Hiro, Aichi Kokuki K.K. at Eitoku Plant, Nagoya (660, Spring 1942 - April 1944)
  • Yokosuka D4Y2 Model 12:
    • Manufacturer: Dai-Ichi Kaigun Koku Gijitsusho (11th Naval Air Arsenal) at Hiro, Aichi Kokuki K.K. at Eitoku Plant, Nagoya (326, April - August 1944)
    • Production: October 1944 - ?
  • Yokosuka D4Y3: 536
    • Manufacturer: Dai-Ichi Kaigun Koku Gijitsusho (11th Naval Air Arsenal) at Hiro, Aichi Kokuki K.K. at Eitoku Plant, Nagoya (536, May 1944 - February 1945)
  • Yokosuka D4Y4: 296
    • Manufacturer: Dai-Ichi Kaigun Koku Gijitsusho (11th Naval Air Arsenal) at Hiro, Aichi Kokuki K.K. at Eitoku Plant, Nagoya (296, February - August 1945)
    • Production: 1945
  • Total: 2,033, 2,038
    • Manufacturer: Aichi, Aichi Kokuki K.K., Dai-Ichi Kaigun Koku Gijitsusho (11th Naval Air Arsenal) at Hiro (215, April 1944 - August 1945)
    • Production: Spring 1942 - August 1945

Variants

  • Prototype: Powered by Daimler-Benz DB 600G (950 HP).
  • Yokosuka D4Y1: First production model.
  • Yokosuka D4Y1 Model 11, Suisei Carrier Bomber Model 11: Strengthened wing spars. Improved dive brakes.
  • Yokosuka D4Y1 KAI: Had catapult equipment installed to allow for use from small carriers.
  • Yokosuka D4Y1-C, Navy Type 2 Carrier Reconnaissance Plane Model 11: Reconnaissance. Had a K-8 camera placed in the rear of the fuselage. Two 72.6 gallon / 330 liter drop tanks could be installed under the wings.
  • Yokosuka D4Y1-Ca:
  • Yokosuka D4Y2, Yokosuka D4Y2 Model 12, Suisei Carrier Bomber Model 12: Had a Aichi Atsuta 32 engine (1,400 HP).
  • Yokosuka D4Y2 KAI, Suisei Carrier Bomber Model 12A: Had 13 mm Type 2 in rear cockpit.
  • Yokosuka D4Y2a KAI: Had catapult equipment installed.
  • Yokosuka D4Y2-S, Suisei-E Night Fighter: Night fighter. Wasn't successful against B-29s as it had no radar. Had 20 mm Type 99 Type 2 cannon mounted obliquely in fuselage.
  • Yokosuka D4Y3, Yokosuka D4Y3 Model 33, Suisei Carrier Bomber Model 33: Had Kinsei 62 radial engine.
  • Yokosuka D4Y3a, Suisei Carrier Bomber Model 33A: Had 13 mm Type 2 in rear cockpit.
  • Yokosuka D4Y4, Suisei Special Attack Bomber Model 43: Suicide bomber. Had one crewman. Had Kinsei 62 radial engine. Carried 1,764 lb / 800 kg bomb under the fuselage.
  • Yokosuka D4Y5, Suisei Carrier Bomber Model 54: Was to have Nakajima Nk9C Homare (1,825 HP) engine. Never produced.

Usage

Preproduction models were deployed in April 1942 on the Soryu. Due to its capabilities the D4Y1-Cs were deployed for reconnaissance.

Units

Midway

The first aircraft to be lost were on the Soryu when it was sunk at Midway in June 1942.

Battle of the Philippine Sea

The 1st, 2nd, and 3rd Kodu Sentais were equipped with 174 D4Ys (141 Suisei, 33 D4Y1-C). They sustained heavy casualties before any could reach the American carriers.

One D4Y, piloted by Rear Admiral Arima, was possibly the first used in a suicide attack against the USS Franklin.

Last Futile Attack

On August 15, 1945, eleven D4Ys were used in Kamikaze attacks off of Okinawa. Included in these was one D4Y4 flown by Admiral Ugaki.

Specifications

  Yokosuka D4Y Suisei
Type Carrier dive bomber , carrier reconnaissance
Crew 2
Dimensions  
Span 37' 8.75"
11.5 m
Length 33' 6.5"
10.22 m
Height 12' 3.25"
3.74 m
  Yokosuka D4Y1 Suisei
Type Bomber, Dive Bomber
Crew 2; Pilot, Radio Operator
Engine (Type) Aichi AE1A Atsuta, Aichi AE1A Atsuta 12 (Daimler-Benz DB 601A)
Cylinders Inverted V-12, V-12
Cooling Liquid
Net HP 1,200
Propeller blades 3, 3 metal constant speed
Dimensions  
Span 37' 8", 37' 8.75"
11.5 m
Length 33' 6", 33' 6.375", 33' 6.5"
10.22 m
Height 12' 0.6875", 12' 1", 12' 3.25"
3.675 m, 3.74 m
Wing area 254.027 sq ft
23.6 sq m
Weight  
Empty 5,379 lb
2,440 kg
Loaded 8,047 lb
3,650 kg
Loaded - Maximum 9,370 lb
4,250 kg
Performance  
Speed at 15,585' / 4,750 m 343 mph
552 kph
Speed - Cruising at 9,845' / 3,000 m 265 mph
Climb to 9,840' / 3,000 m 5.2 minutes, 5 minutes 14 seconds
Service ceiling 32,480'
9,900 m
Range 975 - 2,417 miles, 978 miles
1,570 - 3,890 km
Range - Maximum 2,417 miles
Armament 3: MG
Nose 2: 7.7 mm MG, 7.7 mm Type 97
Cockpit - rear 1: 7.92 mm MG, 7.92 mm Type I
Bombs 683 lb, 1,234 lb
560 kg
  Yokosuka D4Y2 Suisei
Type Dive Bomber, Reconnaissance
Crew 2
Pilot, Navigator/Radio Operator
Engine (Type) Aichi Atsuta 31 (DB 601E), Aichi AE1P Atsuta 32
Cylinders V-12
Cooling Liquid
Net HP 1,380, 1,400
Propeller blades 3, 3 metal constant speed, 3 metal Mitsubishi-Hamilton constant speed
Dimensions  
Span 37' 8.75", 37' 10"
11.5 m
Length 33' 6.375", 33' 6.5", 33' 7"
10.2 m, 10.22 m
Height 12' 3.25"
3.74 m
Wing area 254 sq ft, 254.027 sq ft
23.6 sq m
Weight  
Empty 5,420 lb, 5,514 lb
2,460 kg, 2,501 kg
Loaded 8,276 lb, 8,610 lb
3,754 kg, 3,910 kg
Loaded - Maximum 10,267 lb
4,657 kg
Performance  
Speed at 17,225' / 5,250 m 360 mph
Speed at 19,680' / 6,000 m 361 mph
578 kph
Speed - Cruising - 75% Power 205 mph
328 kph
Speed - Cruising at 6,560' / 2,000 m 265 mph
Climb 2,270' per minute
690 m per minute
Climb to 9,845' / 3,000 m 4 minutes 36 seconds
Climb to 20,000' / 6,000 m 9.2 minutes
Service ceiling 32,400', 35,105'
9,880 m, 10,700 m
Range 909 miles
Range at 205 mph / 328 kph 1,320 miles
2,110 km
Range - Maximum 2,239 miles
Armament  
Nose 2: 7.7 mm MG, 7.7 mm Type 97 MG
Cockpit - Rear 1: 7.7 mm MG
1: 7.92 mm MG, 7.92 mm Type 1 MG
Bombs 1,234 lb
560 kg
Bombs - Internal 1,100 lb
500 kg
Bombs - Wings Light Bombs
  Yokosuka D4Y3 Suisei
Type Carrier dive bomber
Crew 2
Engine (Type) Mitsubishi MK8P Kinsei 62, Mitsubishi MK8P Kinsei
Cylinders Radial, 14, Radial 14
Cooling Air
Net HP 1,560
Propeller blades 3, 3 metal constant speed
Dimensions  
Span 37' 8.75"
11.5 m
Length 33' 6.375", 33' 6.4", 33' 6.5"
10.22 m
Height 12' 3.2", 12' 3.25"
3.74 m
Wing area 254.027 sq ft, 254.03 sq ft, 254.04 sq ft
23.6 sq m
Weight  
Empty 5,514 lb
2,501 kg
Loaded 8,276 lb
3,754 kg
Loaded - Maximum 10,267 lb
4,657 kg
Performance  
Speed at 19,849' / 19,850' / 6,050 m 357 mph
575 kph
Speed - Cruising at 9,845' / 3,000 m 207 mph
Climb to 9,840' / 9,845' / 3,000 m 4 minutes 35 seconds, 4.55 minutes, 4.6 minutes
Service ceiling 34,449', 34,450'
10,500 m
Range 944 miles, 945 miles, 945 - 1,796 miles
1,520 km, 1,520 - 2,890 km
Range - Maximum 1,796 miles
Armament  
Nose 2: 7.7 mm MG, 7.7 mm / 0.303" Type 97 MG
Cockpit - Rear 1: 7.92 mm MG, 7.92 mm Type 1 MG
1: 13.2 mm / 0.5" Type 2
Bombs 1,234 lb, 1,235 lb
560 kg
  Yokosuka D4Y4 Suisei
Type Dive Bomber
Crew 1
Engine (Type) Mitsubishi MK8P Kinsei
Cylinders Radial 14
Cooling Air
Net HP 1,560
Propeller blades 3, 3 metal constant speed
Dimensions  
Span 37' 8.75"
11.5 m
Length 33' 6.375", 33' 6.5"
10.22 m
Height 12' 3.25"
3.74 m
Wing area 254.027 sq ft
23.6 sq m
Weight  
Empty 5,809 lb
2,635 kg
Loaded 10,013 lb
4,542 kg
Loaded - Maximum 10,463 lb
4,746 kg
Performance  
Speed at 19,355' / 5,900 m 350 mph
Speed - Cruising at 9,845' / 3,000 m 230 mph
Climb to 16,405' / 5,000 m 9 minutes 22 seconds
Service ceiling 27,725'
8,450 m
Range 1,024 miles
Range - Maximum 1,611 miles
Armament  
Nose 2: 7.7 mm Type 97 MG
Bombs 1,764 lb
800 kg

Sources:

  1. Fighting Aircraft of World War II, Editor: Karen Leverington, 1995
  2. Aircraft of WWII, Stewart Wilson, 1998
  3. World War II Airplanes Volume 2, Enzo Angelucci, Paolo Matricardi, 1976
  4. The Encyclopedia of Weapons of World War II, Chris Bishop, 1998
  5. Japanese Aircraft of the Pacific War, René J Francillon, 1970
20th Century American Military History Crucial Site