Admiral Beez
Major
Is the Mitsubishi Ki-73 a real design? What engine?
Mitsubishi Ki-73 - real or napkin fighter?
- Thread starter Admiral Beez
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ODonovan
Airman 1st Class
The Mitsubishi "Steve" 
Mitsubishi Ha-203-II 24 cylinder, horizontal H, liquid-cooled, inline engine - 2,600 HP
Projected speed: 466 mph
The "Steve" at Dave's Warbirds
Just a thought, but with the tapering shape of the fuselage and the massive power of the engine, I would've seen a fin fillet in it's future, very similar to the Mustang's.
-Irish
Mitsubishi Ha-203-II 24 cylinder, horizontal H, liquid-cooled, inline engine - 2,600 HP
Projected speed: 466 mph
The "Steve" at Dave's Warbirds
Just a thought, but with the tapering shape of the fuselage and the massive power of the engine, I would've seen a fin fillet in it's future, very similar to the Mustang's.
-Irish
- Thread starter
- #4
Admiral Beez
Major
Perhaps Mitsubishi should have bought a license to produce the Napier Sabre or Rolls-Royce Exe or Vulture, upon which Japan engineers can work out the kinks. If Stalin could get a Nene license, why not release X-engine designs to Japan?The Mitsubishi "Steve"
Mitsubishi Ha-203-II 24 cylinder, horizontal H, liquid-cooled, inline engine - 2,600 HP
Projected speed: 466 mph
The "Steve" at Dave's Warbirds
Just a thought, but with the tapering shape of the fuselage and the massive power of the engine, I would've seen a fin fillet in it's future, very similar to the Mustang's.
-Irish
How do you reckon all of this might happen, and when?
- Thread starter
- #6
Admiral Beez
Major
Why did they give up on liquid cooled engines? Like the Italians, they only Axis that seemed to sort out this configuration was the Germans.
Because Mitsubishi decided to concentrate on the air-cooled engines like Kinsei, Kasei and Zuisei as its original models to develop products most effectively. In other words, Mitsubishi refused to be the all-rounder for the military who always dreamed a dream. Its rival Nakajima had been bankrupted when the war was over but Mitsubishi survived with this cost awareness.
- Thread starter
- #8
Admiral Beez
Major
Wasn't Nakajima known as Fuji Heavy Industries after the war, now called Subaru? I didn't know they went bankrupt.
Ah, confused a little you might be, Admiral. The reason why the British would not export equipment to Japan before the war was because in the mid '30s, the British became suspicious of Japan's intentions and withdrew diplomatic support for the country, which had previously been an ally to which engines and aircraft were supplied - see the 1921 British Naval Mission commanded by Col The Master of Sempill. As a result of this closure of ties, Sempill and other Brits who had gone to Japan with military missions (including naval pilot Frederick Rutland, otherwise known as 'Rutland of Jutland' for carrying out the first spying of an enemy fleet from the air on the prelude of the Battle of Jutland in 1916) were accused of treason for supplying military secrets to the Japanese government. The case against Sempill revolved around a Blackburn flying boat powered by RR Kestrel engines, which Sempill had told the Japanese about in advance of a sale. Odd that the firms involved were not prosecuted or similarly accused. This cutting of ties effectively meant the Japanese had no support for any of the British equipment they had purchased or supplied to them immediately after the Great War, so there was nae chance the Japanese would get British engines from that time onward.
As for the Russians getting jet engines, that was after WW2, so hardly applies to this discussion. Why would the Japanese want a Napier Sabre to power a piston engined aircraft that wasn't ever built, after the end of WW2?
- Thread starter
- #11
Admiral Beez
Major
Thanks, very informative. My note was meant as somewhat tongue in cheek, though Japan did buy licenses pre-war for Allied tech, such as the Showa/Nakajima L2D. I wouldn't have been surprised if the Japanese had tried to get a look at what X and H format engines the Allies were working on.
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Shortround6
Major General
X and H engine engine formats were hardly new even if novel.
However getting them to actually work (not break in service) was a lot harder than many people thought.
Napier had made an X- 16(sort of a squashed one) cylinder engine in the 20s. Packard had built several X-24s (or two V-12s placed one on top of the other) before 1931.
The Italians had built several W-18s.
getting them to run at high speed without being destroyed by vibration (or not enough bearing surface) was a problem.
However getting them to actually work (not break in service) was a lot harder than many people thought.
Napier had made an X- 16(sort of a squashed one) cylinder engine in the 20s. Packard had built several X-24s (or two V-12s placed one on top of the other) before 1931.
The Italians had built several W-18s.
getting them to run at high speed without being destroyed by vibration (or not enough bearing surface) was a problem.
Bingo.
Thread on the Ki-73 here: Mitsubishi Ki-73 super high-speed aircraft
This goes into engine choice and it appears that the configuration in the links provided might not have been how the aircraft appeared at any rate.
fubar57
General
GregP
Major
Regarding post #3, the Mustang dorsal fin was due to increasing the HP from 1100 - 1200 in the Allison P-51A to some 1600 in the Merlin P-51B/C and simultaneously losing vertical area when they cut down the turtledeck for the P-51D/K AND adding a larger cord prop with an extra blade ... meaning loss of side area aft due to added blade area forward of the center of lift. That required compensation of some sort for added power and lost side area, and the solutions include a redesign of the fuselage fin mating and adding some side area well aft of the center of pressure / lift by means of a larger fin or the dorsal fin. In the event, they chose the dorsal fin for minimal production line disruption. The fin already had a fuselage design for structural attachment, and a dorsal was the easiest solution.
It helped, but did not entirely eliminate the destabilizing effects of added power and loss of vertical area. The P-51D/K does NOT have good spin characteristics, though the stall is relatively benign if the needle and ball are centered when it stalls. If you are slipping or skidding, you will almost certainly drop a wing / invert and wind up in a spin or incipient spin.
I am not sure, but it is also possible some relief was had by adding down and or right thrust in the engine mount area for the P-51D/K. I'd have to check.
With the Ki-73, if it was designed for the HP and fin area in the first place, there would have been no need for additional dorsal fin area. Had a more powerful engine been fitted later, then very possibly you would see the dorsal addition as a means to restore yaw stability.
It helped, but did not entirely eliminate the destabilizing effects of added power and loss of vertical area. The P-51D/K does NOT have good spin characteristics, though the stall is relatively benign if the needle and ball are centered when it stalls. If you are slipping or skidding, you will almost certainly drop a wing / invert and wind up in a spin or incipient spin.
I am not sure, but it is also possible some relief was had by adding down and or right thrust in the engine mount area for the P-51D/K. I'd have to check.
With the Ki-73, if it was designed for the HP and fin area in the first place, there would have been no need for additional dorsal fin area. Had a more powerful engine been fitted later, then very possibly you would see the dorsal addition as a means to restore yaw stability.
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