IJN Service Airplane Development Program Designations

[snark]

Hi Folks

This is my list of (documented; not speculative) IJN Service Airplane Development Program designations. Any additions/corrections are welcome. This table is strictly for my own files. Thanks. Harry

Known SADP Designations:

• Kawanishi K-10 14-Shi High-speed Reconnaissance Seaplane [E15K Shiun]
• Kawanishi K-20 15-Shi Fighter Seaplane [N1K Kyofu]
• Kawanishi K-30 Transport Flying Boat [H8K2-L Seiku]
• Kawanishi K-60 Long-range 80-ton Flying Boat (project)
• Kawanishi K-90 (KX-2) 17-Shi Interceptor Fighter (Ko) [J3K Jinpu] (cancelled)
• Kawanishi K-100 (KX-1) 17-Shi Land-based Attack Plane (cancelled)

• Mitsubishi M-20 14-Shi Interceptor Fighter [J2M Raiden]
• Mitsubishi M-50 17-Shi Carrier Fighter [A7M Reppū]
• Mitsubishi M-60 16-Shi Land-based Attack Plane [G7M Taizan] (cancelled)
• Mitsubishi M-70 17-Shi Interceptor Fighter (Otsu) [J4M Senden] (cancelled)

• Nakajima N-20 18-Shi Interceptor Fighter [J5N Tenrai]
• Nakajima N-40 18-Shi Land-based Attack Plane [G8N Renzan]
• Nakajima N-50 17-Shi Carrier Reconnaissance Plane [C6N Saiun]

• Kugisho Y-10 13-Shi Carrier Bomber [D4Y Suisei]
• Kugisho Y-20 15-Shi Land-based Bomber [P1Y Ginga]
• Kugisho Y-30 17-Shi Land-based Recce Plane [R1Y Seiun] (cancelled)
• Kugisho Y-40 18-Shi Land-based Reconnaissance Plane [R2Y Keiun]
• Kugisho Y-50 All-wooden trainer version of D3A Carrier Bomber [D3Y1-K Myojo]

 

[hesham]

Nice work Snark,

here is also Kawanishi K-120 & K-200;

http://www.secretprojects.co.uk/forum/index.php/topic,661.msg7765/highlight,k-120.html#msg7765

 

[snark]

Hi Hesham

Thanks for the kind words!

I'm aware of these designations but I'm hesitant to add them to my list because of uncertainty about their Pacific War origins. Does anyone have Pacific War-era Japanese documentation of these projects?

Of course, given Blackkite's amazing research and subsequent revelations concerning Project Z/Fugaku, I suppose anything is possible.

The IJN/IJA late-war projects were certainly visionary... Best, Harry

 

[snark]

New addition:

• Nakajima N-10 (3K) 14-Shi Carrier Attack Plane [B6N Tenzan]

Harry

 

[hesham]

Nice find Snark.

 

[snark]

Another new addition:

• Mitsubishi M-80 19-Shi All-wood Land-based Attack Plane [Tozan] (cancelled)

From Ishiguro, Ryusuke and Januszewski, Tadeusz, Japanese Anti-submarine Aircraft in the Pacific War. ISBN 978-83-65281-39-5, pages 124 - 133

 

[hesham]

Another new addition:

• Mitsubishi M-80 19-Shi All-wood Land-based Attack Plane [Tozan] (cancelled)

From Ishiguro, Ryusuke and Januszewski, Tadeusz, Japanese Anti-submarine Aircraft in the Pacific War. ISBN 978-83-65281-39-5, pages 124 - 133

Nice find snark.

 

[snark]

Hi Folks


In “Japanese Anti-submarine Aircraft in the Pacific War”, by Ishiguro and Januszewski, there is reference to the “Jitsu Kei Bango numbering system of development programs for experimental aircraft…” Unfortunately, the authors did not include a Kanji rendition of this phrase, which makes further research by “monolingual” folks like me really difficult.

I’ve been researching the Service Airplane Development Program (SADP) designations for some time, but have never before seen this phrase. Perhaps there is still some new information on this topic to be found in Japan, since the authors subsequently revealed the previously-unmentioned Mitsubishi M-80?


FYI:

Reply by Email very kindly provided by Ryusuke Ishiguro:

"Jitsu Kei Bango is short from Jitsuyo-ki Shisei Keikaku Bango (実用機試製計画番号)
or Shisei-ki ryaku bango (試製機略番号) - short numerical system about program of prototypes, as: M-70, N-60 or another."

Phrase literally translates as "Practical Machine Trial Manufacture Plan number". I believe this system was conceived as an attempt to ensure that proposed designs were relevant to future requirements. First time I've seen this terminology.

Best Regards,

Harry

 

[snark]

Hi Folks


In “Japanese Anti-submarine Aircraft in the Pacific War”, by Ishiguro and Januszewski, there is reference to the “Jitsu Kei Bango numbering system of development programs for experimental aircraft…” Unfortunately, the authors did not include a Kanji rendition of this phrase, which makes further research by “monolingual” folks like me really difficult.

I’ve been researching the Service Airplane Development Program (SADP) designations for some time, but have never before seen this phrase. Perhaps there is still some new information on this topic to be found in Japan, since the authors subsequently revealed the previously-unmentioned Mitsubishi M-80?


FYI:

Reply by Email very kindly provided by Ryusuke Ishiguro:

"Jitsu Kei Bango is short from Jitsuyo-ki Shisei Keikaku Bango (実用機試製計画番号)
or Shisei-ki ryaku bango (試製機略番号) - short numerical system about program of prototypes, as: M-70, N-60 or another."

Phrase literally translates as "Practical Machine Trial Manufacture Plan number". I believe this system was conceived as an attempt to ensure that proposed designs were relevant to future requirements. First time I've seen this terminology.

Best Regards,

Harry

Updated Known SADP Designations*​

• Aichi A-80 (AM-24) 17-Shi Special Attack Bomber [M6A Seiran]
• Aichi A-90 (AM-25) 18-Shi-Hei Night Fighter [S1A Denko]
• 
  
• Kawanishi K-10 14-Shi High-speed Reconnaissance Seaplane [E15K Shiun]
• Kawanishi K-20 15-Shi Fighter Seaplane [N1K Kyofu]
• Kawanishi K-30 Transport Flying Boat [H8K2-L Seiku]
• Kawanishi K-60 Long-range 80-ton Flying Boat (project)
• Kawanishi K-90 (KX-2) 17-Shi-Otsu Interceptor Fighter [J3K/J6K Jinpu] (cancelled)
• Kawanishi K-100 (KX-1) 17-Shi Land-based Attack Plane (cancelled)
• 
  
• Mitsubishi M-20 14-Shi Interceptor Fighter [J2M Raiden]
• Mitsubishi M-50 17-Shi-Ko Carrier Fighter [A7M Reppū]
• Mitsubishi M-60 16-Shi Land-based Attack Plane [G7M Taizan] (cancelled)
• Mitsubishi M-70 17-Shi-Otsu Interceptor Fighter [J4M Senden] (cancelled)
• Mitsubishi M-80 19-Shi All-wood Land-based Attack Plane [Tozan] (cancelled)
• 
  
• Nakajima N-10 (3K) 14-Shi Carrier Attack Plane [B6N Tenzan]
• Nakajima N-20 18-Shi-Otsu Interceptor Fighter [J5N Tenrai]
• Nakajima N-40 18-Shi Land-based Attack Plane [G8N Renzan]
• Nakajima N-50 17-Shi Carrier Reconnaissance Plane [C6N Saiun]
• Kugisho Y-10 13-Shi Carrier Bomber [D4Y Suisei]
• Kugisho Y-20 15-Shi Land-based Bomber [P1Y Ginga]
• Kugisho Y-30 17-Shi Land-based Recce Plane [R1Y Seiun] (cancelled)
• Kugisho Y-40 18-Shi Land-based Reconnaissance Plane [R2Y Keiun]
• Kugisho Y-50 All-wood trainer version of D3A Carrier Bomber [D3Y1-K Myojo]

* SADP designations were assigned at the proposal stage. By the time a design reached its final status, substantial configuration changes may have occurred.

 

[Stargazer]

Updated Known SADP Designations​

Thanks. The list looks pretty much the same as the previous versions. Have you changed anything?
When looking at the chronology, some missing numbers seem easy to guess, others less:

• For Kawanishi, between K-30 and K-90, there were exactly five types submitted to the IJN:
  • KX-8 Soku Experimental Large Transport Flying Boat [K-60]
  • 13-Shi Attack (G5K) Taizan
  • 17-Shi Experimental Land Fighter (submitted in 1942)
  • 17-Shi Experimental Land Attack Plane (also 1942)
  • 17-Shi Experimental Large Flying Boat (also 1942)

It is therefore very likely that the latter four received the numbers K-40, -50, -70 and -80.​

• For Mitsubishi, it's a little more complicated because I can find no submittal between M-20 and M-50.
  However, the G6M "Betty" (and perhaps the G4M Hamaki/"Betty" with it too?) seems a good candidate for M-10.
  The Experimental Patrol Plane Q2M Taiyo could be M-90 since it's a 1944 project like the Tozan/M-80.
  
  
• For Nakajima, I can find no IJN type between the J5N Tenrai and the G8N Renzan to fill the N-30 slot... The only possibility seems the slightly earlier 15-Shi Seaplane Fighter or A6M-N Reisen, a version of Mitsubishi's famous "Type 0". For later numbers, the 19-Shi Super Heavy Bomber G10N Fugaku, 19-Shi Special Attack Plane J9Y Kikka, 20-Shi Carrier Fighter "A8N" and 20-Shi Special Attack Plane "D5N" Tōka could easily have received the numbers 60 to 90.
  
  
• For Aichi, it is surprising that so many numbers are unknown... Looking at the chronology, it's tempting to associate the designations A-10 to A-70 with the models AM-17 to AM-23 that preceded the AM-24/A-80 Seiran: in that case we would have A-10 for the 11-Shi Carrier Bomber (later Type 99), or D3A "Val"; A-20 for the 12-Shi Two-seat Recce Seaplane, or E12A; A-30 for the 12-Shi Three-Seat Recce Seaplane or E13A "Jake"; A-40 for the 13-Shi Experimental High-speed Reconnaissance Plane, or C4A; A-50 for the 13-Shi Flying Boat Trainer, or H9A; A-60 for the 14-Shi/16-Shi Reconnaissance Seaplane or E16A Zuiun/"Paul"; and A-70 for the 16-Shi Carrier Attack, or B7A Ryūsei/"Grace"... The only problem with that theory is that the SADP system does not seem to have been in use before 1938-39 for the other manufacturers!
  
  
• For Yokosuka/Kugisho, it seems that the MXY series aircraft were not concerned by the SAPD system. I suppose the Y-20 designation didn't apply to the P1Y1-S Byakko and P1Y2-S Kyokko since the SAPD designations applied to the programs at their beginning, and those Night Fighter versions were afterthoughts...

 

[snark]

Hi! Thanks for your observations. You're quite right - The only real change is the addition of the Aichi entries, courtesy of user "ZZY2001", which I felt are significant, since no other proven Aichi entries are known.

Best Regards, Harry