Did Northrop and Vought Help Design the Zero

[Shortround6]

 

[Snautzer01]

Everybody should know the A6M was inspirated by the Bloch MB 151 as evidenced by the Nakajima Sakae being a by product of the Gnome & Rhone R 14 engine...


Bloch MB151-L'Aéronautique-decembre 38
View attachment 761343

No both were watered down versions of...

Grand dutch design. Koolhoven FK58.

 

[MiTasol]

Everybody should know the A6M was inspirated by the Bloch MB 151 as evidenced by the Nakajima Sakae being a by product of the Gnome & Rhone R 14 engine...


Bloch MB151-L'Aéronautique-decembre 38
View attachment 761343

Yep - same smooth cowls, all round vision canopy, retracting tailwheel, etc, etc. Just as valid a claim as Hughes, Northrop, Vought et al.

 

[GregP]

Metallurgy?
The Japanese used very advanced alloys for the A6M that were similar to 7075. It allowed the skin to be much thinner than contemporary designs.

Build technology?
The A6M was flush riveted at a time when most western companies were still getting their head around mushroom headed rivets

Construction techniques?
Any place he could, Hirokoshi built in lightness - the A6M airframe was a series of lightening holes held together with the minimum amount of aluminum sheet. In fact, the airframe was so light and flimsy, any Western Air Force would have rejected the design out of hand.

It was an incredibly light aircraft for its time, with plenty of power, but it was the end of an era.
It was a transitional design, the ultimate dogfighter, but it was at the crossroads between traditional dogfighters, and their eclipsing by the emerging energy fighters. Against the fighter designs of the 30's, it was a top dog, but come the energy fighters entering from1943, its days were quickly numbered.

The alloy had little to do with it other than being broadly similar in characteristics to what became 2024. The Japanese added Zinc to produce "Extra Super Duralumin." It was strong, to be sure, but they used thinner skins primarily to reduce weight. The design had to take in the strength of the skin, yes, but had they used standard aircraft aluminum, all it would have required was additional internal structure (ribs, bulkheads, stringers, and spars) to make it as strong, albeit slightly heavier.

Horikosji designed the A6M for +6 gs with a 100% safety factor instead of the +8 gs and 50% safety factor the U.S.A. used in many cases. Some US fighter were designed to be +7 / +7.5 g airplanes. The F4U Corsair comes to mind immediately.

 

[ThomasP]

The alloy had little to do with it other than being broadly similar in characteristics to what became 2024. . .

ESD (Extra Super Duralumin} was almost the same composition as today's 7076.

Japan started using ESD in a large scale in 1940, with production of the A6M2 being the first(?), gradually spreading to other aircraft as the war progressed. Japan began using the ~equivalent of 7075 in early-1943.

The US and UK both started producing similar alloys during the war from mid- to late-1943, but the impetus for the development and production came from the analysis of samples taken off the Japanese A6M2 structure - captured in 1942. The story that it was developed in parallel in the US is a myth perpetuated by the propaganda of the time, and the wish to deny credit where credit was due.

The US and UK used the 7000 series very little during the war - I think its first major use was in the B-29, but I may be wrong.

 

[MiTasol]

I seem to remember Lockheed was an early adopter as well but cannot remember which aircraft.

 

[GrauGeist]

So just curious:
Which American fighter did Horikoshi copy when he designed the A5M?

Asking for a friend.

 

[Thumpalumpacus]

So just curious:
Which American fighter did Horikoshi copy when he designed the A5M?

Asking for a friend.

Why, the Fokker D.XXI, of course!

 

[SaparotRob]

(Ahem). The Horten Brothers.

 

[V1710]

I always wondered if the SBD Dauntless had a little Northrop 3A in it.

 

[GrauGeist]

I always wondered if the SBD Dauntless had a litte Northrop 3A in it.

The SBD was developed from Northrop's BT.

 

[yosimitesam]

The alloy had little to do with it other than being broadly similar in characteristics to what became 2024. The Japanese added Zinc to produce "Extra Super Duralumin." It was strong, to be sure, but they used thinner skins primarily to reduce weight. The design had to take in the strength of the skin, yes, but had they used standard aircraft aluminum, all it would have required was additional internal structure (ribs, bulkheads, stringers, and spars) to make it as strong, albeit slightly heavier.

Horikosji designed the A6M for +6 gs with a 100% safety factor instead of the +8 gs and 50% safety factor the U.S.A. used in many cases. Some US fighter were designed to be +7 / +7.5 g airplanes. The F4U Corsair comes to mind immediately.

Yes. The alloy that the Japanese developed was called (back then) 75ST and now is called 7075. It's somewhat lighter than 202x alloys but significantly stronger. It was known in the "West" (which is why it had a name) but was considered too brittle for use in aircraft. The Japanese developed a sophisticated heat treatment that allowed their version of the alloy to be much less brittle and quite suitable for aircraft. This allowed for thinner (lighter) skin as well as lightening some larger components. The U.S. "reverse engineered" the treatment process during the war and, late in the war, began using the alloy, also. It was used extensively in the B-50, which was the improved B-29 which had the R-4360 engines and which was under development when the war ended.

 

[ThomasP]

Correction to my above post.

The B-29 may not have been (was probably not?) the first US aircraft to incorporate 75S(7075) aluminum alloy to any significant degree/benefit.

The war-time produced B-29 did not use 75S(7075) aluminum alloy. At some point in its post-war production the main wing was redesigned in order to handle heavier loads and higher TOGWs. I do not know when/if this design change started being implemented on the B-29. The B-50 had a similar design change for its main spars using 75S from the start of production.

 

[buffnut453]

Yes. The alloy that the Japanese developed was called (back then) 75ST and now is called 7075. It's somewhat lighter than 202x alloys but significantly stronger. It was known in the "West" (which is why it had a name) but was considered too brittle for use in aircraft. The Japanese developed a sophisticated heat treatment that allowed their version of the alloy to be much less brittle and quite suitable for aircraft. This allowed for thinner (lighter) skin as well as lightening some larger components. The U.S. "reverse engineered" the treatment process during the war and, late in the war, began using the alloy, also. It was used extensively in the B-50, which was the improved B-29 which had the R-4360 engines and which was under development when the war ended.

Thanks for this post, Sam. So, rather than Japan copying US technology for the Zero, it seems the US reverse-engineered Japanese technology that was used in the Zero. I find the irony more than a little amusing.

 

[R Leonard]

This is the famous Koga Zero #4593 completed in February 1942, here in a hangar at NAS San Diego on 28 September 1944.
You might note the different shades of metal work. The darker panels are US repair/replacements, the lighter metal work is Japanese original.

 

[Admiral Beez]

No both were watered down versions of...

Grand dutch design. Koolhoven FK58.

View attachment 761344

It's too bad the DEI didn't get a few dozen Koolhoven FK58 to reinforce their Fokkers.

 

[SaparotRob]

Correction to my above post.

The B-29 may not have been (was probably not?) the first US aircraft to incorporate 75S(7075) aluminum alloy to any significant degree/benefit.

The war-time produced B-29 did not use 75S(7075) aluminum alloy. At some point in its post-war production the main wing was redesigned in order to handle heavier loads and higher TOGWs. I do not know when/if this design change started being implemented on the B-29. The B-50 had a similar design change for its main spars using 75S from the start of production.

I was going to say something but decided against it.

 

[Shortround6]

It's too bad the DEI didn't get a few dozen Koolhoven FK58 to reinforce their Fokkers.

What have you got against the Dutch Pilots?

 

[yosimitesam]

Thanks for this post, Sam. So, rather than Japan copying US technology for the Zero, it seems the US reverse-engineered Japanese technology that was used in the Zero. I find the irony more than a little amusing.

Same here. "Necessity is the mother of invention." The A6M designers had stringent and difficult requirements to meet. And they met them.

 

[special ed]

Notice the apparent Bureau Number is ZERO-2