Mitsubishi A7M Reppu ("Sam")

[Stargazer]

Much more handsome than Kartveli's beer barrels, if you ask me!!! ;D

 

[blackkite]

Oh Kartveli's beer barrels!
I like P-47. It's a gorgeous fighter.

 

[Artie Bob]

Having grown up in the USA during WWII, I dreamed of flying P-51s and a little later, the P(F)-82s. After flying for Almost 60 years (with only a very brief period of military flying-I wasn't very good), reading a bit and looking at some statistics, if one had the choice (which of course you wouldn't, but just say you did) a P-47 would probably been a better selection if they wanted to survive the war. IIRC, a greater percentage of P-47 aces survived compared to P-51s and P-38s. The late model 47s were quite fast and had improved range capabilities, but it was the ability to absorb punishment and get back that I admire. The R-2800 was the USA's true jewel of an engine, powerful and reliable and with the turbo, good at altitude. The Thunderbolt did cost almost twice as much as the Mustang and with the greater logistic demands, it made sense for the USAAF to standardize on the latter. So, it may not have been so pretty, but the P-47 had a lot of positive characteristics.

Best Regards,

Artie Bob

 

[Stargazer]

I can't argue with diehard P-47 fans. You've got arguments for you... :

I still prefer more slender aircraft, but of course the looks have little to do with the reliability and/or survivability of a design...

 

[T-50]

I say both aircraft are awsome,real muscelair types!!

 

[blackkite]

Reppu-kai
Candidate Engine : ①Mitsubishi MK9A(HA43) 11type with turbo charger(with inter cooler or
without inter cooler)
②Mitsubishi MK9B(HA43) 21type with Vulkan Coupling drive mechanival
supercharger(with inter cooler or with out inter cooler)
③ Mitsubishi MK9C(HA43) with single stage 3 speed mechanical supercharger without inter cooler
④ Mitsubishi MK9C(HA43) with two stage 3 speed mechanical superchrager
⑤ Nakajima NK9 with intercooler
Finally MK9A(HA43) 11type with turbo charger and inter cooler was selected.
Estimated maximum speed ： over 345kt(638km/h) altitude 11000m
Time to climb to 10000m ： 15minutes
Endurance ： 30minutes at maximum power
2.5 hours at cruising speed 225kt(416km/h)
Armament ： 30mm cannon×4(wing), 30mm cannon×2(fuselage)
Source ：Reppu and Reppu-kai, Gakken, 2004, ISBN4-05-602990-3

 

[blackkite]

Hi!

 

[blackkite]

Having grown up in the USA during WWII, I dreamed of flying P-51s and a little later, the P(F)-82s. After flying for Almost 60 years (with only a very brief period of military flying-I wasn't very good), reading a bit and looking at some statistics, if one had the choice (which of course you wouldn't, but just say you did) a P-47 would probably been a better selection if they wanted to survive the war. IIRC, a greater percentage of P-47 aces survived compared to P-51s and P-38s. The late model 47s were quite fast and had improved range capabilities, but it was the ability to absorb punishment and get back that I admire. The R-2800 was the USA's true jewel of an engine, powerful and reliable and with the turbo, good at altitude. The Thunderbolt did cost almost twice as much as the Mustang and with the greater logistic demands, it made sense for the USAAF to standardize on the latter. So, it may not have been so pretty, but the P-47 had a lot of positive characteristics.

Best Regards,

Artie Bob

Many thanks Artie Bob. Your post is very precious and impressive.

 

[blackkite]

Hi! Reppu-kai model. Enjoy.


http://www.maroon.dti.ne.jp/wingqs-bmc/repu_kai.htm

 

[blackkite]

Hi! Reppu-kai drawings. Enjoy.
The chief engineer of Reppu-kai was famous Jiro Horikoshi.
Jiro Horikoshi thought that Reppu-kai was too heavy compared with it's engine power because of heavy armor and armaments.


http://www.warbirds.jp/kakuki/kaksasie/hon/A7M3-J2.html

 

[JFC Fuller]

Blackkite,


Once again, thank you for an excellent and very informative thread! Do you know how much was progress was made on the Reppu-Kai? Was there a prototype under construction?

 

[blackkite]

Blackkite,


Once again, thank you for an excellent and very informative thread! Do you know how much was progress was made on the Reppu-Kai? Was there a prototype under construction?

Hi! Please give me some time.

 

[T-50]

I must say this is a awsome topic! the Reppu is one of my faforite ww2 warfighters!and now comes mor and more data of the so called super Reppu.It was if builded a powe beast especially with the turbo charcher! It kicked a lot of US fighter pilots if it had the chance to go into production!

 

[blackkite]

Thanks T-50 san.
Repuu development plan was
Mockup completed in the 20th of November 1944
The first plane without armament completed in February 1945
The second plane with armament completed in April 1945
The third plane with armament completed in May 1945
But Mockup and many drawings were lost by B-29's bombing to Mitsubishi Nagoya factory in march 1945.
When the end of the war, mockup was under construction in Matsumoto factory.

 

[Pepe Rezende]

Hi! Reppu-kai drawings. Enjoy.
The chief engineer of Reppu-kai was famous Jiro Horikoshi.
Jiro Horikoshi thought that Reppu-kai was too heavy compared with it's engine power because of heavy armor and armaments.


http://www.warbirds.jp/kakuki/kaksasie/hon/A7M3-J2.html

IJN insist to use an inadequate engine at Reppu. Horikoshi's choice was the Mitsubishi Ha43. IJN imposed the Nakajima Homare. With the Homare, Reppu was underpowered! It's the same mistake made with Zero. Mitsubishi's choose its Kinsei engine. Navy oficials imposed the Sakai. It's interesting to see that the best Zero performer, the A6M8, used the Kinsei instead of the Sakai. It was armoured, had self sealing tanks, was well armed and, in theory, could combat Hellcats in equal terms. IJN retarded Reppu operation in two years. If Navy's officers were not so stuborn, Japan could use the Reppu in 1944! B-29s would had a very dangerous foe ahead.


Cheers


Pepe

 

[Pepe Rezende]

Having grown up in the USA during WWII, I dreamed of flying P-51s and a little later, the P(F)-82s. After flying for Almost 60 years (with only a very brief period of military flying-I wasn't very good), reading a bit and looking at some statistics, if one had the choice (which of course you wouldn't, but just say you did) a P-47 would probably been a better selection if they wanted to survive the war. IIRC, a greater percentage of P-47 aces survived compared to P-51s and P-38s. The late model 47s were quite fast and had improved range capabilities, but it was the ability to absorb punishment and get back that I admire. The R-2800 was the USA's true jewel of an engine, powerful and reliable and with the turbo, good at altitude. The Thunderbolt did cost almost twice as much as the Mustang and with the greater logistic demands, it made sense for the USAAF to standardize on the latter. So, it may not have been so pretty, but the P-47 had a lot of positive characteristics.

Best Regards,

Artie Bob

The Brazilian Air Force used P-47Ds at Italy. One of them returned without the outer port wing after a chock with a factory chimney! The pilots love it!

 

[blackkite]

Hi! Reppu-kai drawings. Enjoy.
The chief engineer of Reppu-kai was famous Jiro Horikoshi.
Jiro Horikoshi thought that Reppu-kai was too heavy compared with it's engine power because of heavy armor and armaments.


http://www.warbirds.jp/kakuki/kaksasie/hon/A7M3-J2.html

IJN insist to use an inadequate engine at Reppu. Horikoshi's choice was the Mitsubishi Ha43. IJN imposed the Nakajima Homare. With the Homare, Reppu was underpowered! It's the same mistake made with Zero. Mitsubishi's choose its Kinsei engine. Navy oficials imposed the Sakai. It's interesting to see that the best Zero performer, the A6M8, used the Kinsei instead of the Sakai. It was armoured, had self sealing tanks, was well armed and, in theory, could combat Hellcats in equal terms. IJN retarded Reppu operation in two years. If Navy's officers were not so stuborn, Japan could use the Reppu in 1944! B-29s would had a very dangerous foe ahead.


Cheers


Pepe

Thanks Pepe. Your opinion might have been same as Jiro Horikoshi's one.

 

[windswords]

Blackkite,

Thank you for all the info and drawings on the A7M. According to Wikipedia:

A7M1 : Initial model powered by 1,491 kW (1,999 hp) Nakajima Homare 22 engine. Three built.
A7M2 : Revised version with 1,641 kW (2,201 hp) Mitsubishi Ha-43 engine. Five prototypes.
A7M3 : Proposed land-based fighter version with supercharged Ha-43 engine. Not built.
A7M3-J : Proposed land-based fighter version. Not built.


As for the P-47 it was very underrated because the Mustang got all the attention. The final versions (P-47D, P47M, and P47-N) were all very fast, could out dive anything, could out roll most everything, and had more firepower than most every other fighter. Because it had a radial engine it would not get coolant leak from a single bullet hole. Coming back from a mission over Japan and having to ditch in the ocean was problematic with the P-51's under belly scoop. I was told that often the crew chiefs were able to coax 3000 horsepower out of the r-2800 engine (rated for 2800 hp).

 

[blackkite]

Wow R-2800 was a dream engine. 3000hp!!
We want R-2800 and V-1650 at the day.

 

[windswords]

The Americans had the advantage of very high octane aviation fuel and good maintenance facilities to try out things like overboosting the engines.

The R2800 official War Emergency Power rating of 2,800 hp is equal to 2,090 kW

Pratt & Whitney's last radial piston engine was the 28-cylinder Wasp Major (4,362.50 inches - 71.5 liters). Later models (after WWII) developed ratings up to 4,300 horsepower (3200 kW)

Back to the Reppu. Was the A7M2 with the Ha-43 engine supercharged? Or was that only the A7M3? A7M1 had the Homare engine. Was that engine ever supercharged?

 

[Artie Bob]

Essentially All WWII full size aircrfat engines were supercharged. The differences were the type of supercharging with fixed, variable or multiple speed supercharger drives, single or two stage supercharging, withor with out intercooling and exhaust driven turbochargers which would at that time have been a form of second stage supercharging. There were actually a few more variations , but that covers most of the applications that saw actual service.
Further on the R-2800, I talked with the P&W test stand engineer for R-2800 development during WWII. IIRC, He stated that the standard basic engine on the test stand had run 100 hours at 3000 hp on standard USA fuel and water injection (no methanol) and ultimately reached 3800 hp. He felt that 4000 hp probably could have been reached, but it was not important as the test stand conditions could not be duplicated in an aircraft. The main point is that if detonation was avoided, the engine could reliably run indefinitely at very high power levels.
Finally, PN numbers were defined when anti detonation values exceeded that of 100 % octane. Research on aviation fuel in the USA by the end of WWII had resulted in fuel mixtures with a PN rating approaching 300. Using this fuel, boost pressure would not be limited by detonation, but rather the mechanical ability of the engine to handle the power output.
Best Regards,
Artie Bob

 

[blackkite]

Hi! You can see mechanical supercharger centrifugal compressor blades and air inlet duct right side of the cylinder of Homare engine.
If air inlet duct is connected to the duct from turbo charger , it become two stage supercharging system. (The first stage was turbo supercharging system and the second stage was mechanical supercharging system). Also you can see air inlet duct to the mechanical supercharger of Mitsubishi MK9A engine for Reppu.
The last picture shows HA-43-42 engine with Vulkan coupling drive super charger instead of mechanical drive for Shinden interceptor.

 

[windswords]

Thank you Artie for that explanation.

I should been more clear and asked if the engines in question (Homare, Ha-43) were turbo supercharged.

 

[blackkite]

Hi! Mitsubishi HA43-11 (MK9A) engine for A7M2 Reppu didi not have turbo charger. It had only single stage 2 speed mechanical supercharger.
This engine was Ki-83's engine, detached turbo charger, and installed to A7M2.
Take off power : 2,200hp, 2,900r.p.m, boost : +520mm
2,070hp/1,000m(with the first speed mechanical supercharging)(2,800r.p.m), boost : +420mm
1,930hp/5,000m(with the second speed mechanical supercharging)(2,800r.p.m), boost : +420mm

 

[blackkite]

Rolls-Royce Merlin 60 series engine had 2 stage 2 speed mechanical supercharger with inter cooler.
It's a heart of spitfire and Mustang. Sorry off topic.

 

[blackkite]

Hi! Zero fighter's Sakae engine.
You can see air inlet duct from engine cowling upper front to mechanical supercharger and many air ducts from mechanical supercharger to engine cylinders.


Source : THE GREAT BOOK OF WORLD WARⅡ AIRPLANES, CRESCENT BOOK, ISBN 0-517-16024-2

 

[Aurum]

Kasei 11 was NEVER installed to Raiden.
That was Kasei 13 an prototipe & Kasei 23 on serial crafts. These versions had coaxial cooling fan infront of engine

 

[Stargazer]

Topics merged. The A7M1, A7M2 and A7M3 are all combined into one single topic for now!

 

[CherryBlossom]

Hi, does anyone have the original cockpit photo of the A7M Reppu? I can't seem to find it anywhere and it has now come to where i have been asking different area's on the web for it. I hope someone has it. Thanks

Regards Cherry

 

[blackkite]

Hi!
http://www.secretprojects.co.uk/forum/index.php/topic,20427.msg200067.html#msg200067

 

[blackkite]

Hi!
http://gunsight.jp/c/cockpit-3D.htm
http://gunsight.jp/a/hunatu05.htm　Please click left side A7M. And use Japanese English translater.Cockpit photo of Reppu is not found still now.

 

[G11N]

Does anyone know what happened to the A7M's at wars end?
Mr. Dyer's new book lists 10 total completed airframes: 2 A7M1's, 7 A7M2 prototypes and 1 production model.
I believe he listed the production model, 3 prototype A7M2's and both M1's as still being airworthy at the end of hostility's, but I've never come across any TAIC documentation of evaluation or heard it listed as captured equipment.
I find it hard to believe the US wouldn't have been interested in testing out the zeros replacement.
Perhaps they where intentionally destroyed before the occupation forces arrived?

 

[G11N]

Here's a couple pictures from the Mitsubishi museum. They had some A7M manuals on display. Unfortunately that's about all they had for the A7M.

 

[Kuropentacle]

Does anyone know what happened to the A7M's at wars end?
Mr. Dyer's new book lists 10 total completed airframes: 2 A7M1's, 7 A7M2 prototypes and 1 production model.
I believe he listed the production model, 3 prototype A7M2's and both M1's as still being airworthy at the end of hostility's, but I've never come across any TAIC documentation of evaluation or heard it listed as captured equipment.
I find it hard to believe the US wouldn't have been interested in testing out the zeros replacement.
Perhaps they where intentionally destroyed before the occupation forces arrived?

Japanese wiki says some protopypes was sent to USA and few stayed in Japan.

 

[blackkite]

After the end of the war, release order has also gone out to Reppu fighter from U.S. forces like other Japanese aircraft. That Kofukuda lieutenant commander of a navy answered "delivery impossibility" because every prototype and production model were impossible to fly.
However, the person concerned of Mitsubishi airplane recollected that one A7M1 prototype model sent to Matsumoto was restored and delivered to U.S.
It's unclear which is true.
Reppu isn't found by the investigation performed in the United States after it passes fairly after the war. Mass production number 1 was thrown away in the Nagoya harbor offing just after the end of the war, but the confirmation is still impossible because a jetty has been built in its location after the war.
(Japanese wikipedia)

https://www.youtube.com/watch?v=KECVch6quFo

 

[blackkite]

Hi! Reppu in action.
https://www.youtube.com/watch?v=MdYWgbUFevg

 

[G11N]

Thanks for all the info guys! I also found in the book 'broken wings of the samurai' that it might also be possible one was loaded on a ship along with the rest of the captured planes but was cut loose during stormy seas to cut weight. The book says its an unconfirmed story though.

 

[blackkite]

Thanks for all the info guys! I also found in the book 'broken wings of the samurai' that it might also be possible one was loaded on a ship along with the rest of the captured planes but was cut loose during stormy seas to cut weight. The book says its an unconfirmed story though.

HmHm....
Someday we want to see replica. The engine will be R-2800? ;D

 

[CherryBlossom]

Hello chaps,

Bumping an old thread

Do we have anything on the A7M3 specifically? Perhaps original drawings, info on its engine/turbocharger? I see more of the A7M3-J (which i am more fond of personally) but hear very little about the other model.

Do we have much on it?

Cheers!

Cherry

 

[blackkite]

Hello chaps,

Bumping an old thread

Do we have anything on the A7M3 specifically? Perhaps original drawings, info on its engine/turbocharger? I see more of the A7M3-J (which i am more fond of personally) but hear very little about the other model.

Do we have much on it?

Cheers!

Cherry

Hi!
MK9C engine(Ha-43-51 series) : Single stage three speed mechanical supercharger