Why the early war Japanese fighters were structurally fragile and unarmored?

[Jenisch]

They designed to the mission set by the Japanese Army and Navy and could have matched anything we produced had they changed the mission and had the raw materials for critical parts.

Yes, and actually they had the raw materials initially, this was a problem only later.

One pre war example of excellent product the IJA didn't accepted was the Ki-12: Nakajima Ki-12 - Wikipedia, the free encyclopedia

One late war example, also from the Army, was the Ki-87: Nakajima Ki-87 - Wikipedia, the free encyclopedia

Notorius about the Ki-87:

A further variant, the Ki-87-II, powered by a 3,000 hp Nakajima Ha.217 (Ha.46) engine and with the turbo-supercharger in the same position as the P-47 Thunderbolt, never went further than the drawing board.

The Ki-87 prototype achived 697 km/h. Since IJA didn't included boost setting, the aircraft was probably faster. Now imaginate such aircraft with the 3000 hp engine, high octane fuel and good materials - certainly a match to any design in the world.

 

[tyrodtom]

That 697km/h would have to be a projected top speed, not actual. The same article says it only had 5 test flights, and never retracted it's landing gear.

 

[GregP]

I'm thinking of an amazingly impressive airplane ... but I won't identify it due to the liklihood of being adjectivally mugged. Just making a joke ... not being snobnoxious.

 

[davparlr]

I'm saying that we're splitting hairs over my invocation of an adjective.

I'm sure this is true. To me, for something to be amazing, I have to have my jaw drop and say to myself "how does it do that?" When I read about some of the long Zero missions it does that, when looking at the Sakae stats it does not. It just looks typical. Just a personal opinion.

 

[cherry blossom]

The story of "Corky" Meyer seeing the Pratt Whitney logo with an eagle and "Quality Reliability" seems to be true. Similarly the picture at 01 three dollar bill G W Bush « Voices from Russia has the words "Federal Reserve Note". However, I do not believe that the Nakajima Sakae has a close relationship with any Pratt Whitney engine. Apart from little details like having different bores and strokes, there is the point that all the valves are driven from in front in the Sakae while P&W two row radials drove the valves of the back row from behind.
....

Help! I am confused and fear that I have mislead you. I said that the valves of the Sakae were driven from in front. However, the thread on Japanese engines contained a post by Aurum http://www.ww2aircraft.net/forum/engines/data-base-japanese-aircraft-engines-19466-8.html#post881086 and replies by Shinpachi that suggested that the valves of rear cylinders of the Sakae were driven from the back. You can find pictures which show this including Planes of Fame Air Museum - 3989c | Flickr - Photo Sharing! from Planes of Fame, File:Nakajima Sakae.jpg - Wikipedia, the free encyclopedia and http://www.preservedaxisaircraft.com/Japan/Engines/Ha35MOF.jpg. Unfortunately, there is also a photograph from Prima Air Museum Pima Air Museum - Nakajima Sakae (Prosperity) which clearly shows the valves driven from the front (and which I had previously believed). Thus either the Prima photograph is mislabelled or the Sakae design evolved with the early models having all valves driven from in front and the later versions for the A6M5 having the rear valves driven from behind. Can anyone reduce my level of confusion?

 

[GregP]

I'll look at our Zero this weekend and let you know. It has a Sakae 21 engine.

 

[war eagle]

The answer to jenisch,s question is not fully answered by a blinding of aviation science you have to look at the prevailing situation that presented itself to the japanese military and its airforces in the early stages of hostilities.In October 1937 its opening spec requirements were unprecedented manouverability,a top speed higher than any existing monoplane fighter (310 mph),a fast climb rate (9800 feet in 3.5 mins).These hastily revised changes came as a result of combat reports from china which showed up the deficiences of its predecesser the A5M "CLAUDE" itself only a few months into combat service.The price that had to be paid to get within these strict guidelines due to the lack of a suitably powerful engine was a severe pairing down of what the military somewhat naively considered non essential weight ie all toughened glass,all pilot protection,no self sealing fuel tanks,no engine protection i suppose they thought if they produced the fastest,nimblist,fastest climbing aircraft available then the only planes being hit would be the enemies.The problem with that theory of course is that air supremecy is only fleeting against big industrialised nations with unlimited raw material resources which the US is.The japanese domination of the pacific skies was never going to prevail for long and as better fighters came into the fray the zero soon became outclassed and by mid 43 the gulf in performance was massive and by the time the zero was given an engine that allowed all the features foolishly omitted in late 39 to be included the japanese imperial land and carrier based airforces were all but irrepairably destroyed and were a shadow of the force that took off for pearl harbour in late 41.

 

[Vincenzo]

also if Zero become outclassed soon, in mid '43 most of USAAF fighters in japanese theaters were P-39 and P-40.

 

[FLYBOYJ]

also if Zero become outclassed soon, in mid '43 most of USAAF fighters in japanese theaters were P-39 and P-40.

But they were being used less and less in an air-to-air combat role. By mid 1943 the P-38 was the dominant USAAF air-to-air fighter.

•The 39th FS, of the 35th FG, received P-38's in late summer 1942.
•The 9th FS, of the 49th FG, in January, 1943.
•The 80th FS, of the 8th FG, also in January, 1943.
•It wasn't until mid-1944 that the 475th FG, an all-Lightning outfit, was activated.

I think you'll find that by early 1943 the P-39 was harldy used in an air-to-air capacity by the USAAF

 

[Vincenzo]

Flyboy i've not the right file on this pc but in mid' 43 all USAAF had around 76 operational fighter group of this 14 had P-38 (and we knewn that his was used also in MTO) around 6 used also P-38 and 37 used P-3940 so probably the 3940 were used also in air to air at time

 

[FLYBOYJ]

Flyboy i've not the right file on this pc but in mid' 43 all USAAF had around 76 operational fighter group of this 14 had P-38 (and we knewn that his was used also in MTO) around 6 used also P-38 and 37 used P-3940 so probably the 3940 were used also in air to air at time

Probably based on local operations but in the larger picture, the P-38 was the primary air to air fighter. Examine the major campaings During the summer of 1943. 115 P-38Gs were assigned to the 5th AF and eventually saw their way into the 475th FG. The P-40 still saw service well into 1944 but I think the P-39 and P-400s starting going away by mid 1943 when the 80th FG was moved to from Port Moresby, New Guinea to Mareeba, Queensland, Australia. This unit has been operating in New Guinea since Jul 42.

By Mid 1943 I believe the USAAF and the RAAF started to replace their P-39s with newer or different types (I believe the RAAF replaced their P-39s with the Vukte Vengence)

 

[GregP]

OK, I looked at the Sakae 21 engine in our Zero. The rods for the front row come out of the engihe case from the front and push the valve rocker arms from the front side. I did not try to look at the back row.

Hope that answeres your question.

 

[Vincenzo]

back to mid'43 usaaf fighter v/s japanese
july '43
alaska 40 P-38, 126 P-3940 (28 others)
cbi 23 P-38, 201 P-40
pto 0 P-38, 264 P-3940 (23 others)
feto 211 P-38, 471 P-3940 (114 P-47, 6 others)

(others include NF and others day fighters, i'm curious what others day fighters?)

 

[FLYBOYJ]

back to mid'43 usaaf fighter v/s japanese
july '43
alaska 40 P-38, 126 P-3940 (28 others)
cbi 23 P-38, 201 P-40
pto 0 P-38, 264 P-3940 (23 others)
feto 211 P-38, 471 P-3940 (114 P-47, 6 others)

(others include NF and others day fighters, i'm curious what others day fighters?)

Don't know your sources for that, but that has to be in error. PTO "0" P-38s?

 

[drgondog]

The 39th FS of the 35th FG had P-38s in October 42 ---->November 1943, then P-47s for a five months then P51s in mid 1945. The 40th and 41st had P-40s until late 1943 then same pattern as 39th FS.

The 9th FS of 49th had P-38s from February 1943 to November 1943 and got P-47s ------> then all P-38 in mid -1944

The 475th started combat ops w/P-38s in August 1943

Source - Frank Olynyk "Stars and Bars" - squadron historie

 

[Vincenzo]

Don't know your sources for that, but that has to be in error. PTO "0" P-38s?

the source it is the usaaf statistical digest tables 92, 93, 94 and 95,
the numbers 0 is right, probably pto give confusion maybe poa is more clear for you?
feto is the theater with most of combat, 35th, 49th and 475th were all in feto

 

[FLYBOYJ]

the source it is the usaaf statistical digest tables 92, 93, 94 and 95,
the numbers 0 is right, probably pto give confusion maybe poa is more clear for you?
feto is the theater with most of combat, 35th, 49th and 475th were all in feto

That makes sense..