Hagiwara Helicopter Prototypes

hesham

hesham

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hesham said:
From Aviation magazine 1956.
Click to expand...
I did find that one - online archive: https://gallica.bnf.fr/ark:/12148/bpt6k5322701q/f16.item

Please let me share with you results of my recent research on these helicopters:

In the first post you have presented three pictures. The last one is commonly agreed to represent the JHX-4 helicopter. The second is the easiest as the helicopter itself on this picture is signed - the JHX-3 (the same picture is better visible in the link to the french archives above). This helicopter still exist and is on display at the Arakawa Campus, Tokyo (科学技術展示館, >>google img on maps1<< >>google img on maps2<< >>some page on the exhibition<<)

The first picture is the most tricky for me right now. I actually have found one page which states what it is, but it is not really confirmed. But let me start from the books first. Among my private library I was able to find only two mentions of the Hagiwara helicopters. The one is in the second edition of Helicopters & autogyros of the world by Paul Lambermont. It only briefly describes JHX-3 and JHX-4. The other one I found in the ABC Helicopters by J.W.R. Tylor from 1960. It describes JHX-4 and presents the first picture from the first post here. This entry states that it presents the JHX-4 in "its current stripped-down form". I don't really buy this. The helicopters of that era were often made as a truss or frame clad with some plywood or sheet-metal (like Bendix model K). So I expect the striped-down form to represent the same landing gear, controls, the tail rotor transmission, etc. But it is clearly visible that this is not the case. Also it looks like the main vertical and transverse beams are actually a propellant tanks integrated to take some structural load. See it yourself:
IMG_20220717_180742.jpg
JHX-5 - this is the name attached to the other photo of this helicopter:
a36TonaiDepartIke-04.jpg
If I understand it correctly, it was taken in 1959 at the opening event of the roof-top heliport. Source >>page<<

There is at least two pages which also mentions JHX-5 >>link<<, and this is a google translated extract from one of them:
The first is a series of products of the Free Aviation Research Institute established in Tokyo in 1952. Hagiwara JHX-1 to JHX-4 were manufactured as a series of one-man helicopters designed by Gishi Hagiwara.
　The first JHX-1 was equipped with a pulse jet engine at the tip of a rotor with a diameter of 7.3 m, but it had difficulty in igniting the engine, and after starting it made a loud noise and was abandoned early.
　From the next JHX-2, a ramjet will be adopted instead of the pulse jet, and the JHX-2 will be completed in 1955 and the JHX-3 will be completed in September.
　Nonetheless, they were far from being completed, and the Institute for Free Aviation was collapsed. We will complete the JHX-4 with an improved control method.
　This succeeded in climbing to an altitude of 7 m on September 1, assuming that the maximum number of revolutions of the rotor was 600 revolutions.
　However, the sudden landing damaged the aircraft, the rotor touched and bent, and the engine nozzle was deformed, making it unusable.
　The cause of the accident was the excessive rotation of the rotor, but it cost 3 million yen at that time to develop this Unit 4, the funds did not continue, the prototype of JHX-5 was abandoned, and the way to practical use was cut off. rice field.
Click to expand...

This post is getting long, but I'm not done yet.

Most sources states also about existence of JHX-1 (with puls-jet engines) and JHX-2 (with ram-jet engines like others). I failed to find any picture or illustration of JHX-1, but in respect to JHX-2, I've came across this (click to go to source page):
hagiwara2.jpg 2021-06-01.jpg

Almost done. There is also a kind of leaflet on the subject of these helicopters:
CCougb2VIAIdKMM.jpeg
Done. Tell me what you think of it? Do you have some information to complement my findings?
 
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Brilliant work my dear Persil,

honestly it was more than I knew,many thanks.
 
persil said:
I did find that one - online archive: https://gallica.bnf.fr/ark:/12148/bpt6k5322701q/f16.item

Please let me share with you results of my recent research on these helicopters:

In the first post you have presented three pictures. The last one is commonly agreed to represent the JHX-4 helicopter. The second is the easiest as the helicopter itself on this picture is signed - the JHX-3 (the same picture is better visible in the link to the french archives above). This helicopter still exist and is on display at the Arakawa Campus, Tokyo (科学技術展示館, >>google img on maps1<< >>google img on maps2<< >>some page on the exhibition<<)

The first picture is the most tricky for me right now. I actually have found one page which states what it is, but it is not really confirmed. But let me start from the books first. Among my private library I was able to find only two mentions of the Hagiwara helicopters. The one is in the second edition of Helicopters & autogyros of the world by Paul Lambermont. It only briefly describes JHX-3 and JHX-4. The other one I found in the ABC Helicopters by J.W.R. Tylor from 1960. It describes JHX-4 and presents the first picture from the first post here. This entry states that it presents the JHX-4 in "its current stripped-down form". I don't really buy this. The helicopters of that era were often made as a truss or frame clad with some plywood or sheet-metal (like Bendix model K). So I expect the striped-down form to represent the same landing gear, controls, the tail rotor transmission, etc. But it is clearly visible that this is not the case. Also it looks like the main vertical and transverse beams are actually a propellant tanks integrated to take some structural load. See it yourself:
View attachment 681220
JHX-5 - this is the name attached to the other photo of this helicopter:
View attachment 681221
If I understand it correctly, it was taken in 1959 at the opening event of the roof-top heliport. Source >>page<<

There is at least two pages which also mentions JHX-5 >>link<<, and this is a google translated extract from one of them:


This post is getting long, but I'm not done yet.

Most sources states also about existence of JHX-1 (with puls-jet engines) and JHX-2 (with ram-jet engines like others). I failed to find any picture or illustration of JHX-1, but in respect to JHX-2, I've came across this (click to go to source page):
View attachment 681224View attachment 681225

Almost done. There is also a kind of leaflet on the subject of these helicopters:
View attachment 681226
Done. Tell me what you think of it? Do you have some information to complement my findings?
Click to expand...
The JHX-5 was probably just a typo because later in http://hikokikumo.net/a3616-1-IkebukuroSeibu.htm where they predict when each body was made they state that its a JHX-4. And the reason why the stripped down form looks nothing like the first picture is because as it states on the leaflet when it landed it basically destroyed the helicopter due to rough landing and the "stripped down form" is just the JHX-4 partly fixed for exhibition. JHX-5 was going to be made but they spent too much money on making and fixing the JHX-4 so they terminated the idea. Since everything was funded from Hagiwaras pocket he probably went broke.
 
rudejude123 said:
The JHX-5 was probably just a typo because later in http://hikokikumo.net/a3616-1-IkebukuroSeibu.htm where they predict when each body was made they state that its a JHX-4. And the reason why the stripped down form looks nothing like the first picture is because as it states on the leaflet when it landed it basically destroyed the helicopter due to rough landing and the "stripped down form" is just the JHX-4 partly fixed for exhibition. JHX-5 was going to be made but they spent too much money on making and fixing the JHX-4 so they terminated the idea. Since everything was funded from Hagiwaras pocket he probably went broke.
Click to expand...
Thank you. This indeed may be de case. My main interest in helicopters is their design, how they are built and why in that way. So I look at the pictures from that angle. As you can see in the first graphic from my previous post, the JHX-4 and what may be JHX-5 are totally different animals - if you imagine JHX-4 stripped down from its cabin then not much matches the other one design. The main pylon is there skew, the same with tail rotor boom, way different skids' cross-tubes.

So in my mind, if it was just repaired to resemble the shape of helicopter, then the changes were very substantial.

The key to solve this mystery would be to gain access to the picture (that from roof-top helipad) and read what was written on the datasheet in front of it.
 

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