Aichi S1A Denkô Night Fighter (AM-25)

[snark]

First, this plane's code is AM25, or some times A90 within Aichi's company, and S1A1 in the IJN. This plane, also called 18 shi-hei sentoki (night fighter projected in Showa 18th, or 1943), was there because the navy wish her to catch and take down the B29s (by the way, the J5N Tenrai was also there at the same time). However at that time, no one knows that B29s would bomb Japan at the altitude of 4000m, thus this plane's fastest speed was at 9000m, and unfortunately she could not catch up with B29 since at 4000m the denko was much slower according to her plan report and performance calculations.

Some great new information here. Thanks a lot!

Question: The mystery designation “A90” revealed here very much resembles the so-called “SADP designations” (実用機試製計画番号) begun by the IJN Aviation Bureau in 1939. I have never seen an Aichi designation of this format and have assumed they were never assigned or had been destroyed at the end of the Pacific War. In your research at Aichi, had you come across any similar designations?

Again, thanks for this much-appreciated information. Regards, Harry

 

[QAZ]

Result of the more based on many documents research, i think probability is high that Denko no.1 was bombed March 12, 1945 at Aichi Eitoku-aircraft plant and Denko no.2 was incinerationed Augast 15, 1945(The day the war ended in Japan).
Here is the video about the S1A1 Denko by me but, I'm sorry this is in Japanese.
But, take a watch 7:34~28:15, there is many information about construction and Performance of the S1A1 Denko. It is easy to understand even for non-Japanese speakers.

View: https://www.youtube.com/watch?v=-tPwHiQx46A

Amazing video, extremely impressive research!

 

[zzy2001]

Some great new information here. Thanks a lot!

Question: The mystery designation “A90” revealed here very much resembles the so-called “SADP designations” (実用機試製計画番号) begun by the IJN Aviation Bureau in 1939. I have never seen an Aichi designation of this format and have assumed they were never assigned or had been destroyed at the end of the Pacific War. In your research at Aichi, had you come across any similar designations?

Again, thanks for this much-appreciated information. Regards, Harry

it absolutly exists! In fact, the document name of denko's wind tunnel's report was simply "A90 wind tunnel report"!

 

[zzy2001]

Amazing video, extremely impressive research!

gladly, I am now cooperating with the video's uploader, and soon we will create a new video about D3A Val, please wait and watch!

 

[snark]

it absolutly exists! In fact, the document name of denko's wind tunnel's report was simply "A90 wind tunnel report"!

Thanks for your rapid reply. I'm thrilled that you discovered and verified this designation! Were you able to come across any other A-?? designations at Aichi? Looking forward to your D3A video. Best Regards, Harry

 

[zzy2001]

Thanks for your rapid reply. I'm thrilled that you discovered and verified this designation! Were you able to come across any other A-?? designations at Aichi? Looking forward to your D3A video. Best Regards, Harry

When you read some business trip reports by Aichi kokuki KK, you will see that the Seiran is A80

 

[snark]

When you read some business trip reports by Aichi kokuki KK, you will see that the Seiran is A80

Really wish I had a way of doing that! Thanks for this new information and for your hard work. Harry

 

[zzy2001]

Very interesting, thank you. It would be appreciated if you like to proceed with further informations.

I would proceed further, if you have any questions feel free to ask me.
The resouces I'd obtained are: "S1A1(Denko) Plan Book" (with official and original blueprints of fuseage of Denko that are used to construct the prototype), "S1A1 Performance Calculations"(calculate the performance of S1A such as top speed and climbing rate by utilizing wind tunnel information), "S1A1 Strength Calculations" (calculate the metal strength of S1A, but only the tail part remains), "S1A1 Wing And Tail Blueprints" (original construction blueprints of wing and tail", and "S1A1 Wind Tunnel Reports" (73 pages of S1A's wind tunnel reports".

 

[zzy2001]

Aichi S1A1 original plans. The nose looks somehow different to the way it's always shown in non-original plans.

View attachment 613954

By the way, this picture comes from "S1A1 Performance Calculations"

 

[zzy2001]

The cover page of Denko's plan struction book (same kind of thing like thesis or essay today), this picture's copy right belongs to Mr. Watanabe so if you are going to use it somewhere else, remember to at a sticker ©渡边哲国.