Yokosuka D5Y Myojo Kai 'special attacker'

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fontessa
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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#16

Post by fontessa » 29 Dec 2022, 20:44

fontessa wrote:
29 Dec 2022, 19:06
Prototype No. 3 seems that one of them took off from Ebetsu Airfield on August 20th.
fontessa
Another web source says Prototype No. 2 flew more than 800km to 福生 Fussa and was transported with Production No.1 to the United States.
I have already arrnged to borrow a book about Ki-106s at Ebetsufrom the city library so that I could read it after the new year. I'll post if I find out anything.

fontessa

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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#17

Post by ShindenKai » 30 Dec 2022, 05:27

fontessa wrote:
29 Dec 2022, 20:44
fontessa wrote:
29 Dec 2022, 19:06
Prototype No. 3 seems that one of them took off from Ebetsu Airfield on August 20th.
fontessa
Another web source says Prototype No. 2 flew more than 800km to 福生 Fussa and was transported with Production No.1 to the United States.
I have already arrnged to borrow a book about Ki-106s at Ebetsufrom the city library so that I could read it after the new year. I'll post if I find out anything.

fontessa
That's fantastic! I hope that book has more images and information! Thank you Fontessa!


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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#18

Post by ShindenKai » 30 Dec 2022, 05:36

As much as I'd like to believe that wing is for a Ki-106, I don't believe it is. The wing in the pics has no appreciable taper- The leading & trailing edges are parallel to each other. The Ki-106 wing mimics the forward swept trailing edges of the Ki-84. Also, the wood that wraps over the leading edge is scalloped, as it would be for a fabric covered wing. It appears to be a wing for a completely different aircraft.

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fontessa
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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#19

Post by fontessa » 30 Dec 2022, 08:15

ShindenKai wrote:
30 Dec 2022, 05:36
As much as I'd like to believe that wing is for a Ki-106, I don't believe it is. The wing in the pics has no appreciable taper- The leading & trailing edges are parallel to each other. The Ki-106 wing mimics the forward swept trailing edges of the Ki-84. Also, the wood that wraps over the leading edge is scalloped, as it would be for a fabric covered wing. It appears to be a wing for a completely different aircraft.
The wing on display does not have ailerons and flaps which had tapers. It looks to me that the red line area in the below picture is displayed.
Ki-106 図 A.jpg
Ki-106 図 A.jpg (18.71 KiB) Viewed 940 times

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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#20

Post by ShindenKai » 30 Dec 2022, 11:37

Fontessa, I'm well aware that the aileron & flap are missing. But as even shown by the red lines, the wing should be tapered. The wing in the pics is not. Also, EACH of the ribs within that section of wing should be progressively smaller towards the wing tip (as should each of the spars), they aren't (notice that the top & bottom surfaces should also be tapering towards each other). With the exception of the three ribs just before the tip, ALL of the ribs are the exact same size. That wing is not from a Ki-106.

Thank you again Fontessa. Looking forward to any information that book brings forth.

This fellow has created absolutely fantastic drawings of the Ki-84, including airfoil shapes.
http://soyuyo.main.jp/ki84/ki84e-1.html

I forgot to mention before but the Horyuji Temple is truly incredible, it must be preserved at all costs. Thank you Fontessa.
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Tachikawa Ki-106 DrawingInternals.jpg

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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#21

Post by ShindenKai » 03 Jan 2023, 01:02

http://soyuyo.main.jp/ki84/ki84e-1.html
-"The incidence is 2 deg. (root) and 0 deg (tip)." <-This is interesting, it's mimicking the 2* of washout that was also used on the Zero. IIRC, Not the same airfoils, but similar "built-in" washout. Reduces the tendency to "tip-stall" therefore making the aircraft easier to handle/maneuver.
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Ki-84 airfoils.jpg

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fontessa
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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#22

Post by fontessa » 18 Jan 2023, 06:44

ShindenKai wrote:
30 Dec 2022, 11:37
Fontessa, I'm well aware that the aileron & flap are missing. But as even shown by the red lines, the wing should be tapered. The wing in the pics is not. Also, EACH of the ribs within that section of wing should be progressively smaller towards the wing tip (as should each of the spars), they aren't (notice that the top & bottom surfaces should also be tapering towards each other). With the exception of the three ribs just before the tip, ALL of the ribs are the exact same size. That wing is not from a Ki-106.
You were right. Prior to Ki-106 production, Oji Paper Ebetsu Factory dispatched engineers to Tachikawa Aircraft, the Ki-106's designer, in April 1944. Along with the training, they copied the original drawings and sent them to Ebetsu. In October 1944, the Ebetsu Factory started manufacturing Ki-106 based on these drawings. On the other hand, the wing and fuel tank in the photo were drawn and prototyped over three months in early 1944 at the Hokkaido Industrial Research Institute. No Ki-106 drawings were available there at this time. In other words, this wing was different from the Ki-106 wing. The reason for the trial production was probably the confirmation of materials, adhesives, and construction methods. I guess it was the reason why it took 3 months.

ki-106.jpg

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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#23

Post by ShindenKai » 20 Jan 2023, 03:25

fontessa wrote:
18 Jan 2023, 06:44
You were right. Prior to Ki-106 production, Oji Paper Ebetsu Factory dispatched engineers to Tachikawa Aircraft, the Ki-106's designer, in April 1944. Along with the training, they copied the original drawings and sent them to Ebetsu. In October 1944, the Ebetsu Factory started manufacturing Ki-106 based on these drawings. On the other hand, the wing and fuel tank in the photo were drawn and prototyped over three months in early 1944 at the Hokkaido Industrial Research Institute. No Ki-106 drawings were available there at this time. In other words, this wing was different from the Ki-106 wing. The reason for the trial production was probably the confirmation of materials, adhesives, and construction methods. I guess it was the reason why it took 3 months.
fontessa
Thank you for the update Fontessa. Any information as to what aircraft was used to practice/test wood construction techniques? Thank you again.

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fontessa
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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#24

Post by fontessa » 21 Jan 2023, 04:38

ShindenKai wrote:
20 Jan 2023, 03:25
Any information as to what aircraft was used to practice/test wood construction techniques?
I believe IJAAF has not disclosed military secret drawings other than basic information to civilian organizations. I think that the shape of the wing may have been considered at the Hokkaido Industrial Research Institute.

fotessa

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Re: Yokosuka D5Y Myojo Kai 'special attacker'

#25

Post by ShindenKai » 01 Feb 2023, 08:13

fontessa wrote:
21 Jan 2023, 04:38
ShindenKai wrote:
20 Jan 2023, 03:25
Any information as to what aircraft was used to practice/test wood construction techniques?
I believe IJAAF has not disclosed military secret drawings other than basic information to civilian organizations. I think that the shape of the wing may have been considered at the Hokkaido Industrial Research Institute.

fotessa
That's too bad, but understandable. Thank you again for the follow-up, Fontessa.

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