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Japan's Nakajima Ki-49 Donryu (storm dragon) bomber¹
Nakajima Ki-49 Donryu (dragon swallower) bomber²
Army Type 100
Allied Name: "Helen"^1,2

Nakajima Ki-49, "Helen" bomber:

Nakajima Ki-49, "Helen" bomber:

Nakajima Ki-49, "Helen" bomber:

Nakajima Ki-49, "Helen" bomber:

Nakajima Ki-49, "Helen" bomber:

Design

The Nakajima Ki-49 was intended to replace the Ki-21 and was designed in 1938.^1,2

Unfortunately, the Ki-49 was said to be difficult to handle by the crews.¹

Protecting the Crew

Unusual for a Japanese aircraft, but the Ki-49 did have armor and self sealing fuel tanks to help protect the crews.¹

Prototype

The prototype of the Ki-49 first flew in August 1939.^1,2

The Ki-49-III prototype first flew in March 1943.²

The Ki-58 first flew in December 1940.²

The Ki-80 first flew in October 1941.²

Production

Production ended in December 1944.²

• Prototype: 23¹
• Prototype and pre production: 10²
• Ki-49: 796¹
• Ki-49-I: 129²
  • Production started in August 1941.²
• Ki-49-II: 669²
• Ki-49-III: 6²
• Ki-58: 3²
• Ki-80: 2²
• Total: 819²
  • Produced by: Nakajima (769)², Tachikawa Hikoki (50)²

Variants

• Prototype: Had Nakajima Ha-5 radial engines (1,080 HP).^1,2 Later prototypes had a Nakajima Ha-41 installed.²
• Ki-49-I: Production model.¹
• Ki-49-II: Entered service in late 1942.¹ Due to mounting losses to Allied fighters, it had additional armament.^1,2 Self sealing fuel tanks were installed.² Upgraded bomb sight on later models.²
• Ki-49-IIa:
• Ki-49-IIb: Heavier caliber MGs in the nose, ventral, and tail.²
• Ki-49-III: Had Nakajima Ha-117 radial engine (2,420 HP).²
• Ki-58: Heavy escort fighter.² Had ventral gun pack.² Was to be used in China.²
• Ki-80: Lead ship for a formation.²

Usage

First Sentai Equipped

The 61st Sentai was first equipped with the Ki-49-I in December 1941.¹

Early Use

The Ki-49 equipped units used them in raids in China, New Guinea, and over Australia's Northwest Territory.^1,2 The first raid on Darwin, Australia occurred on February 19, 1942.²

Poor performance and heavy losses had the Ki-49 modified to have a magnetic anomaly detection (MAD) equipment for hunting submarines.²

Last Use

During the last year of the war the Ki-49s were used as night fighters, transports, and in suicide attacks at Mindoro in December 1944.¹

	Nakajima Ki-49-I Donryu1,2	Nakajima Ki-49-II Donryu2	Nakajima Ki-49-IIa Donryu1
Type	Medium bomber2	Medium bomber2	Heavy bomber1 Medium bomber2
Crew	82	82	81,2
Engine (Type)	2: Nakajima Ha-411,2	2: Nakajima Ha-1092	2: Nakajima Ha-109 piston1
Cylinders	Radial1, Radial 142	Radial 142	Radial1
Cooling
Net HP	1,250 each1, 1,260 each2	1,500 each2	1,500 each1
Propeller blades	3 each2	3 each2	3 each1
Dimensions
Span	67'2 20.42 m2		67' 1/8"1 2.042 m1
Length	55' 1.75"2 16.81 m2	54' 1.5"2 16.5 m2	54' 1 1/3"1 16.5 m1
Height	13' 11.25"2 4.25 m2		13' 11.25"1 4.25 m1
Wing area			743.25 ft2 1 69.05 m2 1
Weight
Empty	13,382 lb2 6,070 kg2		14,396 lb1,2 6,530 kg1,2
Loaded	23,534 lb2 10,675 kg2		25,133 lb1,2 11,400 kg1,2
Performance
Speed			306 mph2 492 kph2
Speed @ 16,405' / 5,000 m			306 mph1 492 kph1
Cruising speed			217 mph2 349 kph2
Climb			1,312'/minute2 400 m/minute2
Climb to 16,405' / 5,000 m			13.6 minutes1
Service ceiling			30,510'1,2 9,300 m1,2
Range			1,243 miles1,2 2,000 km1,2
Maximum range			1,833 miles2 2,950 km2
Armament
Nose	1: 7.7 mm MG2		1: 7.7 mm MG2 1: 12.7 mm Ho-103 MG1
Ventral	1: 7.7 mm MG2		1: 7.7 mm MG2 1: 12.7 mm Ho-103 MG1
Tail	1: 7.7 mm MG2		1: 7.7 mm MG2 1: 12.7 mm Ho-103 MG1
Beam	2: 7.7 mm MG2		2: 7.7 mm MG2 2: 7.7 mm Type 89 MG1
Dorsal	1:20 mm2		1: 20 mm2 1: 20 mm Ho-11
Normal bomb load	1,653 lb2 750 kg2		1,653 lb2 750 kg2
Maximum bomb load	2,205 lb2 1,000 kg 2		2,205 lb1,2 1,000 kg1,2

Sources:

1. Fighting Aircraft of World War II, Editor: Karen Leverington, 1995
2. Aircraft of WWII, Stewart Wilson, 1998

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