Nakadžima Ki 49 Donrjú [Helen]

Nakajima Ki-49 Donryu - přehled verzí

Nakajima Ki-49 Donryu - list of versions


キ 島 キ -49 呑 龍


Japanese name: 呑 龍 - Donryu - Stormy Dragon
Reporting code name: Helen



Designation Aircraft design - description
Nakajima Ki-49 prototype engines Nakajima Ha-5KAI, flown in August 1939, followed by seven pre-series machines.
Nakajima Ki-49-I [col ] operationally deployed in China, where it celebrated success, the deployment in the Pacific showed the predominant negative characteristics,
engines Nakajima Ha-41 with an output of 1,250 horsepower.
Nakajima Ki-49-IIa [col ] installation of more powerful engines Nakajima Ha-109 with an output of 1,540 horsepower, additional crew armor.
Nakajima Ki-49-IIb [col ] more powerful main armament, weight gain leads to deterioration of flight characteristics,
the aircraft is underpowered and less controllable.
Nakajima Ki-49-III [col ] installation of powerful but untuned and unreliable engines Nakajima Ha-117.
Nakajima Ki-58 upravený Ki-49-IIa in the form of a flying cruiser, was overloaded with cannon and machine gun armament, development ended.
Nakajima Ki-80 dva prototypes modified from the Ki-49-IIa, were designed for commanders of bombers, with more powerful engines Nakajima Ha-117,
with more powerful weapons and armor, eventually used to test engines.




Sources used:
René J. Francillon Ph.D., Japanese Aircraft of the Pacific War, Naval Institute Press, Annapolis Maryland, Reprinted 1990, ISBN-0-87021-313-X
Richard M. Bueschel, Nakajima Ki-49 Donryu in Japanese Army Air Force Service, Schiffer Publishing, year 2007, ISBN: 0764303449
author's archive
URL : https://www.valka.cz/Nakadzima-Ki-49-Donrju-Helen-t29261#103699 Version : 0
Nakajima Ki-49 Donryu / Helen
キ49一〇〇式重爆击机 "吞龙″
Ki-49 Army Type 100 Heavy Bomber "Donryu"


The task of developing the successor to the Mitsubishi Ki-21
In 1937, the 大日本帝国陸軍航空本部 Dai-Nippon Teikoku Rikugun Kōkū Hombu (Imperial Army Air Force Command ) commissioned 中島飛行機株式会社 - Nakajima Hikōki Kabushiki Kaisha (hereafter referred to as Nakajima), to design and build the future successor to the heavy bomber currently being introduced://forum.valka.com/topic/view/31499/]Mitsubishi Ki 21[/url]. The Mitsubishi Ki-21's victory over the competing but less successful Nakajima Ki-19 prototype is cited in the literature as the reason for this direct award without competition. To what extent this information is true I do not presume to judge. However, the fact is that Rikugun Kōkū Hombu tried to commission the development of a new aircraft whenever a new type was introduced into the arsenal. This gave the designers ample time to design and test a successor to an aircraft that had just been accepted and had become obsolete or had begun to underperform.


The requirements for the new bomber, which Rikugun Kōkū Hombu had drawn up, were quite demanding for the time, with only a maximum speed of 500 km/h being emphasised, as speed was to be one of the bomber's protection options. The bomb load was to be small by European standards - 1,000 kg, but this was characteristic of the Japanese. The range of at least 2,000 km, a great novelty in the requirements of the Army Air Force was effective passive protection of the crew and self-locking fuel tanks. Work on the project was first undertaken by Engineer Nishimura and later the design team was led by Engineer Koyama. Both designers were certainly familiar with the design of the Mitsubishi Ki-21, as these bombers were produced under license by Nakajima. An equally important source of knowledge was the experience of combat deployment of Ki-21 bombers in China; the Chinese battlefield tested the aircraft in terms of reliability and performance, but given the low effectiveness of the Chinese Air Force, the design flaws concerning the lack of passive protection and weak barrel armament were hardly evident. In this respect, the Ki-49 design, as the new project was designated, was exceptional because the Army Air Forces already required these design features.


Ki-49 design and prototypes
The new Nakajima Ki-49 bomber was designed as an all-metal medium wing, with a semi-elliptical wing, flared centroplane with large Fowler-type flaps on the trailing edge, characterized by their guide rails. The inner part of the wing was extended forward, giving the designers room for the wing fuel tanks. The aircraft's shape also showed a certain amount of elegance, and the proven Nakajima Ha-5-KAI four-cylinder engines were chosen to power the aircraft, which were the engines that originally powered the already unsuccessful Nakajima Ki-19 prototype and later the Mitsubishi Ki-21-Ia. The crew was eight-strong and had one mobile gun Ho-1 in the dorsal gunnery bay and five machine guns Type 89 model 1, these were already considerably obsolete and not very powerful guns that had their ancestry in the British Vickers machine gun, but were widely used in Japan, these machine guns were mounted in the front, rear, in the lower gunnery and in the two side windows in the rear of the fuselage. The first prototype began flight trials in August 1939 and by the end of the year two more prototypes had joined, these were powered by more powerful Ha-41 engines. The two prototypes were accepted into the Army Air Forces armament in March 1941 under the designation "Army Heavy Bomber Aircraft Type 100 Model 1", while a seven-aircraft verification series was being built, differing from each other by minor improvements.


Ki-49-I
The new bombers slowly made their way to the airfield to join the combat troops from August 1941, the Japanese giving them the battle name Donryu (Stormy Dragon) and the Allies later giving them the codename Helen. The Donryu bombers first entered combat in China, but from December 1941, the outbreak of the Pacific War, they appeared wherever Army Air Forces intervened in the fighting, deployed mainly over New Britain and New Guinea for their range, and were also effectively involved in raids on Australia. Intensive combat deployments, and especially clashes with more modern enemy fighter aircraft, brought with them the first really real lessons. The aircraft was well maneuverable and, considering its weight, also manoeuvrable, the passive protection was also very good, but that was the end of the list of positives, the Donryu could only carry 500-750 kg of bombs over a long distance and that was not enough, the speed did not protect the aircraft from fighter attacks and the operational range was not the bomber's strong point. Flying personnel also complained about the low effectiveness of the 7.7 mm machine guns.


Nakajima Ki-49-II
First, the designers managed to replace the Ha-41 engines with the more powerful and higher altitude Nakajima Ha-109 engines. This modification was made in the spring of 1942, and performance improved, but by that time the Allied air force was already changing in quality and quantity. Allied fighter units were receiving modern fighters in significant numbers. Nakajima, responding to the mounting losses of the Donryu bombers, introduced the installation of improved passive protection on the production line, both in the crew compartment and in the fuel tanks. This version was designated Ki-49-IIa. Shortly after the deployment of these aircraft, the defensive armament was further strengthened. The newly introduced Ki-49-IIb version carried powerful large-caliber machine guns in the front, rear and lower gunnery Ho-103, while this greatly strengthened the bomber's defenses, it also increased its weight, making this new version of the Donryu bomber a considerably cumbersome and underpowered machine that could no longer assert itself against the ever-increasing Allied air superiority.


Ki-49-III
The designers decided that for the new upcoming version of the Ki-49-III they would choose engines that would bring back the lost characteristics of the bombers. The choice fell on the powerful 18-cylinder Nakajima Ha-117 engines with a takeoff power of 2,420 hp. In the second half of 1943, six prototypes powered by these engines were produced, the performance was very good, but only if these engines worked well and this was, unfortunately, a very rare occurrence. The engines were untuned, immature and totally unsuitable for installation in mass-produced combat aircraft. This attempt thus ended the development of the Ki-49 as a heavy bomber, a new heavy bomber Mitsubishi Ki 67 Hiryu began to take on this role, but it did not mean that the Donryu disappeared from the skies, the Donryu just began to perform different tasks.


Ki-49 in other roles
-At the time of the introduction of the Ki-49-II version, an attempt was made to make the two Donryu aircraft seekers and destroyers of enemy bombers. The first aircraft carried a powerful searchlight to illuminate the target, and the second aircraft carried a Type 88 75 mm calibre cannon with which to destroy the enemy illuminated bomber. The idea was interesting, but the technique of pursuit, search and destroy was very cumbersome, and the performance of the light bombers was not sufficient for this role.
The -Ki-49-Is, after withdrawal from the bomber force, served in anti-submarine service and carried magnetic anomaly detectors or radar, we must remember that the American submarines were very effective in destroying the Japanese war and merchant fleets and any weapon against them was extremely important.
[The Ki-49-IIs were converted into transports, usually dismantling all armament and leaving only the necessary equipment, and the aircraft could then carry 1,500 kg of cargo.
- The Donryu met the fate of many Japanese aircraft types, towards the end of the war many aircraft were stripped of all armament and equipment and the weight saved was used to carry explosives, the aircraft after this modification could carry 1,600 kg of explosives and was piloted by a crew of only two, the aircraft so modified were deployed for suicide operations.


Aircraft developed from the Ki-49
- Nakajima Ki-58 - This was an escort aircraft designed to provide effective defense for the heavy bomber alliance. This attempt falls between late 1940 and March 1941, three prototypes built at this time by modifying the production Ki-49, these aircraft carried not bombs but a massive armament of five 20 mm Ho-1 mobile guns and three Ho-103 machine guns. The result - the escorted bombers, after carrying out the raid, were relieved of the weight of bombs and were thus faster than their prepared escorts, the army air force stopped the whole action in time. The entire experiment was conducted and evaluated on the Chinese battlefield.


- Nakajima Ki-80- This aircraft was to carry an officer on board to coordinate attacks by groups of bombers, the aircraft carried more effective armour plating for the crew compartments, richer radio equipment and more powerful defensive armament. The increased weight of the aircraft was to be compensated by Nakajima Ha-117 engines, engines that prematurely ended the development of the Ki-49-III due to their unreliability. Only two prototypes were produced and used as flying laboratories to test the new engines.
URL : https://www.valka.cz/Nakadzima-Ki-49-Donrju-Helen-t29261#237590 Version : 0

This post has not been translated to English yet. Please use the TRANSLATE button above to see machine translation of this post.

Použité prameny:
Rene J Francillion Ph.D., Japanese Aircraft of the Pacific War, Naval Institute Press; rok 1987; ISBN-13: 978-0870213137
Václav Němeček, Vojenská letadla 3., Naše vojsko, Praha rok 1992, 3. doplněné vydání, ISBN 80-206-0117-1
Jaroslav Schmid, Stíhací a bombardovací letadla Japonska, díl 2., Nakladatelství Fraus Plzeň, rok 2000, ISBN 80-7238077-x
Richard M. Bueschel, Nakajima Ki-49 Donryu in Japanese Army Air Force Service, Schiffer Publishing, rok 2007, ISBN: 0764303449
L+K 17/1993, str.42, Nakajima Ki-49 Donryu. Václav Němeček
http://www.airwar.ru/enc/bww2/ki49.html
http://brazd.ru/ki49.html
http://www.cofe.ru/avia/N/N-19.htm
www.aviastar.org
http://www.angelfire.com/fm/compass/Donryu.htm
archiv autora
URL : https://www.valka.cz/Nakadzima-Ki-49-Donrju-Helen-t29261#237593 Version : 0
Discussion post Fact post
Attachments


Join us

We believe that there are people with different interests and experiences who could contribute their knowledge and ideas. If you love military history and have experience in historical research, writing articles, editing text, moderating, creating images, graphics or videos, or simply have a desire to contribute to our unique system, you can join us and help us create content that will be interesting and beneficial to other readers.

Find out more