The Nakajima Ki-49 Donryu (storm
dragon) was designed early in 1938 to
replace the JAAF's successful Mitsubishi
Ki-21 heavy bomber which, in
fact, was only just entering service with
sentais based in China and Manchuria,
Later code-named 'Helen', the Nakajima
Ki-49 was a workmanlike design
but was destined to be just not good
enough for the conditions prevailing
over the various fronts in 1942, when
the initial production Ki-49-I (Army
Type 100 Heavy Bomber Model 1)
started operations with the 61st
Hikosentai in China. Production was
preceded by the flight of the first prototype
in August 1939, powered by two
708kW Nakajima Ha-5 KAI
radiais: the more powerful 932kW Ha-41 radial engines were
installed in pre-production versions,
and in the Ki-49-I bomber. In appearance
the 'Helen' was deceptive in size,
for it appeared to be a comparatively
large aircraft because of its proportions:
actually, its dimensions were
similar to those of the Lockheed Hudson.
However, a crew of seven or eight
was crammed into the narrow fuselage.
In the spring of 1942 the usual
steps were taken to increase performance,
protection and defensive firepower.
The Nakajima Ki-49-IIa (Army
Type 100 Heavy Bomber Model 2A),
the first of the new series, was powered
by two Nakajima Ha-109 radial
engines with increased ratings. The
aircraft was fast, well protected by 5mm armour plating and
rubberized fuel cells, and heavily
armed. The Ki-49-IIb was upgunned
with 12.7mm Ho-103 machine guns.
Both the Ki-49-IIa and Ki-49-IIb
were in action with the 7th and 61st
Sentais based in China in the summer
of 1942, and made many attacks on
Chungking and air bases of General
C. L. Chennault's China Air Task Force.
'Helen' bombers equipped the 12th
Sentai, based at Medan and Sabang
(Sumatra) under the 3rd Air Army, and
these attacked objectives in Burma
and eastern India, joining Ki-21s on
some occasions in raids on Calcutta. In
1943 the Ki-49s of the 7th and 61st Sentais,
now operating from Timor, attacked
Darwin to face strong reaction by
the Supermarine Spitfire Mk.Vs of
No.1 Fighter Wing. Units equipped
with Ki-49s suffered most in New
Guinea, where 4th Air Army came
under constant attack on its airfields at
Wewak, But and Dagua after August
1943, when the RAAF and the US 5th
Air Force went onto the offensive. Six
Ki-49-III bombers, powered by very
potent 1805kW engines,
were built as prototypes. Other
variants produced in experimental
form were the Ki-58 escort fighter, and
the Ki-80 escort bomber. Total production
amounted to 819 aircraft. After action
in the Philippines in 1944, Ki-49s
were used with increasing frequency
on suicide missions.
| ENGINE||2 x Nakajima Ha-109, 1119kW|
| Take-off weight||11400 kg||25133 lb|
| Empty weight||6530 kg||14396 lb|
| Wingspan||20.42 m||67 ft 0 in|
| Length||16.5 m||54 ft 2 in|
| Height||4.25 m||14 ft 11 in|
| Wing area||69.05 m2||743.25 sq ft|
| Max. speed||492 km/h||306 mph|
| Ceiling||9300 m||30500 ft|
| Range w/max.fuel||2950 km||1833 miles|
| ARMAMENT||1 x 20mm cannon, 5 x 7.7mm machine-guns, 1000kg of bombs|
|A three-view drawing (752 x 961)|
The Japanese called this a "heavy" bomber, by western standards it would be just about a medium bomber. The concept was for a fast heavily armed, armoured bomber which could reach targets without escort. Hopelessly under powered it failed in it's "raison d'etre" and fell easy prey to Allied fighters. So overall not a great success.
|Hiroyuki Takeuchi, 23.03.2012|
Undoubtedly, the aircraft outperformed the Ki21, but not to the extent that it improved the survivability of the bomber against full on attacks by enemy fighters. On the other hand, the Ki49 were harder to fly and engines were less reliable, causing more non-combat losses.
So as far as the bomber crews were concerned, they could expect longer lives on a Ki21 because there was less chance of accidents and if they were met by a formation of P-47s they were going to get shot down regardless of whether they were on a 21 or a 49.
Did japan ever have a significant number of bombers carrying more than 1 ton.
Nakajima Ki-49 Donryu
Have heard mixed reviews about this one. Some sources say it was a mediocre aircraft surpassed in some ways by the Ki-21 it was designed to replace. Is this actually true? The performance specs seem to say otherwise. Light bomb load, though. Did japan ever have a significant number of bombers carrying more than 1 ton?
Do you have any comments about this aircraft ?