Did Northrop and Vought Help Design the Zero

[fannum]

The wing structure of the A6M bears no commonality with Northrop and Vought's construction, and while the fuselage design is closer, the Mitsubishi elegance is far superior.

Any comparisons with the Hughes H-1 are laughable structurally.

At best, one may muse that Japanese designers took inspiration from the cigarette pack 3-views popular those days, and based development by copying some cards that came in smuggled packs of Chesterfields.

 

[tommayer]

The other one I've heard a lot is that the Zero copied a lot from the Hughes H-1 racer despite that fact that Howard Hughes was well known for being secretive and never really showed the details of the H-1 to anyone outside a small group of Hughes employees and workers.

View attachment 705258

Note, it has all the requisite parts of a small, radial-powered retractable low-wing monoplane, pretty much like all other small, radial-powered retractable low-wing monoplanes.

Howard Hughes no doubt stole the ideas from the drawing boards at Mitsubishi ...

Maybe the best looking piece of machinery of any sort ever? My favorite, anyway. I knew Dick Palmer, who designed it, pretty well.

 

[Barrett]

For decades there was conventional wisdom that the A6M was based on the Hughes H-1 racer.
It wasn't true
but
you know...
the thing...

 

[denoferth]

Thank you, WAFU. Informational posts like your's are the reason I subscribe.

 

[Shinpachi]

In the historical time line -

1. Zero designer Jiro Horikoshi completed the basic structure for A6M in 1936 when he designed A5M Claude.

2. 20 Seversky P-35s were imported to support Sino-Japanese War in 1937 but IJN confirmed A5M was superior in performance.

3. However, Nakajima Aircraft paid attention to P-35's retractable landing gear to adopt it for its B5N in 1937 to beat back old fashioned Mitsubishi B5M with fixed undercarriage in competition.

4. Jiro Horikoshi had no choice but to follow Nakajima with the retractable type for his A6M Zero in 1940.

Source: "Zero Fighter as Short History of IJN Aviation" by Masatake Okumiya and Jiro Horikoshi (1953)

 

[fannum]

It's a foolish designer or engineer who doesn't look around for ideas and solutions.

We're always in danger of underestimating our Japanese. Chinese, Russian, etc. economic or conflict opponents by concentrating on their design shortcuts and ignoring achievements.

Yes, Germany copied US variable pitch propellers between the wars, Japan relied on German and US aircraft engine designs for WWII powerplants, Russia co-opted B-29, RR Nene and Manhattan technology, but the US relied on V-2 engine designs through the Saturn, and took advantage of an overlooked Russian tech paper to develop our stealth leadership.

However, though Luft '46 zealots will insist we stole the Me262 swept wing, those benefits were well known as early as WWI era designs, discussed extensively in '30s NACA papers, and even tried by Bell in their P-59 and X-1 planform studies. Even the early 30s DC-1/2/3 uses a swept wing based on those studies.

 

[BarnOwlLover]

I thought that the DC-3 series used swept wings for the same reason as the original Me-262--to account for a CG/weight distribution shift due to the use of different engines?

 

[Clayton Magnet]

However, though Luft '46 zealots will insist we stole the Me262 swept wing, those benefits were well known as early as WWI era designs

WWI era designers were concerned with critical mach numbers and wave drag in transonic flight?

 

[ThomasP]

From the NASA historians writing the official history of NASA:

". . . NACA also contributed to the development of the swept back wing. In January 1945, Robert T. Jones, a NACA aeronautical scientist, formulated a swept-back-wing concept to overcome shockwave effects at critical mach numbers. He verified it in wind-tunnel experiments in March and issued a technical note in June. His findings were confirmed when German files on swept-wing research were recovered and by German aerodynamicists who came to the United States at the close of the war."

 

[MiTasol]

A quick summary of the items the A6M series has in common with the Hughes Racer, P-66, V-141 and Seversky fighter.

Remember that changing any one of these features requires a significant or major redesign.

I will take photos of the tail gear and some of the items that are pure British and post later along with comparisons with the US equivalent parts later.

EDIT: I am advised by a person with a P-66 manual that the information I had on the wing is incorrect so I have edited it to reflect his information. This change is "from memory" but he will confirm it this weekend

In other words, as far as I am concerned, any claim that the A6M series was copied from any US aircraft is delusional at best.

As others have said many Japanese components were licenced copies of British and US components. In some cases the Japanese were able to permanently overcome known major defects built into the original - for example the breaking trigger spring problem on the Vickers guns.

 

[MiTasol]

It's a foolish designer or engineer who doesn't look around for ideas and solutions.

We're always in danger of underestimating our Japanese. Chinese, Russian, etc. economic or conflict opponents by concentrating on their design shortcuts and ignoring achievements.

Yes, Germany copied US variable pitch propellers between the wars, Japan relied on German and US aircraft engine designs for WWII powerplants, Russia co-opted B-29, RR Nene and Manhattan technology, but the US relied on V-2 engine designs through the Saturn, and took advantage of an overlooked Russian tech paper to develop our stealth leadership.

However, though Luft '46 zealots will insist we stole the Me262 swept wing, those benefits were well known as early as WWI era designs, discussed extensively in '30s NACA papers, and even tried by Bell in their P-59 and X-1 planform studies. Even the early 30s DC-1/2/3 uses a swept wing based on those studies.

I agree in general with your comments, especially the highlighted one, but being a picky bugga take exception to several items. Japan also built a lot of British engines under licence and the Russians did not co-opt the Nene. They built it under licence.

 

[MIflyer]

The F3F had flotation bags that deployed in the event of a water landing.

The Hughes Racer had a wide stance landing gear similar to the Zero and FW-190

The propeller used on the Zero was so similar to US made ones that they had no problem replacing the one on Koga's Zero. Koga's Zero had US made RDF gear.

NACA also contributed to the development of the swept back wing.

As far as the Germans inventing the swept back wing, anybody ever look at any of the Northrop flying wings?

 

[buffnut453]

The F3F had flotation bags that deployed in the event of a water landing.

The Hughes Racer had a wide stance landing gear similar to the Zero and FW-190

The propeller used on the Zero was so similar to US made ones that they had no problem replacing the one on Koga's Zero. Koga's Zero had US made RDF gear.

Floatation bags in naval aircraft have been around since the 1920s. The Brits had them. The US had them. Hardly a ground-breaking technology for the Zero.

Are there any technical commonalities between the undercarriage of the Hughes Racer and those of the Zero or the Fw190? AFAIK, the Zero actually had a unique design feature where the retraction of the mainwheel hooked into a device on the inner wheel flap to bring that into place. I've never seen anything like that on any other aircraft design. Again, can we get beyond generics like "wide stance" and into actual technology that may have transferred?

As for the propellor and RDF, it's already been pointed out that licenced production was a thing in the 1930s, to include variable pitch and constant speed propellers. Bendix and other parts manufacturers sold components wherever they could get business, providing it met export laws. That still doesn't mean there's any association with the Zero and an American-designed aircraft.

None of the points you make get after the groundbreaking characteristics of the Zero - its incredibly long range, high manoeuverability, heavy armament (for its day), and amazing balance of light construction techniques within a generally strong airframe. None of these features were present in ANY Western aircraft design of the 1930s into 1940.

 

[Shortround6]

A number of people had built flotation into carrier aircraft during the 30s. The Blackburn Shark was one and I believe the Skua also had flotation compartments. The British tried using inflatable bags on several types of aircraft.
The F4F was designed with inflatable flotation bags.

From photos there were two different shape bags used. The US also tried to use them on several other types of planes.

Problem with the bags was that an unintended inflation incident (UII) could result in loss of control and loss of the aircraft and crew.

The whole landing gear thing is a red herring.
You can trace wide stance inward retracting landing gear back several years before the Hughes racer. I am not even sure it is patentable.
I mean what is the patentable difference between inward and outward retracting landing gear? Just the direction?
What is patentable would be methods of retraction and methods of locking the landing gear in place, either up or down.

First retractable landing gear?

1911.
Probably very far from 2nd (?)

1921 also note full span leading edge slats and full span trailing edge flaps, interconnected for adjustable airfoil camber in flight.

Interesting note on the Hughes racer. The ONLY shock absorption in the landing gear was the tires, which were tiny.

The "door" is actually a box and is the landing gear leg. The wheel is bolted to the door.

heavy armament (for its day)

Yep, just a bit lighter than 109E-4 (?) and bit debatable against a Hurricane I. The 2 20mm are heavy firepower but they only last for about 7 seconds.
In the summer of 1940 they wasn't a lot better but they only built a couple of dozen Zeros in 1940.

 

[tomo pauk]

The Hughes Racer had a wide stance landing gear similar to the Zero and FW-190

Hurricane's prototype have had the landing gear layout very similar to the Hughes Racer. Perhaps all of them were trying to improve on the Polikarpov I-16?

The propeller used on the Zero was so similar to US made ones that they had no problem replacing the one on Koga's Zero.

Sumitomo was making Hamilton Standard props under licence. In Japan, these props were known as 'Sumitomo Hamilton'.

 

[MiTasol]

The F3F had flotation bags that deployed in the event of a water landing.

The Hughes Racer had a wide stance landing gear similar to the Zero and FW-190

The propeller used on the Zero was so similar to US made ones that they had no problem replacing the one on Koga's Zero. Koga's Zero had US made RDF gear.

As far as the Germans inventing the swept back wing, anybody ever look at any of the Northrop flying wings?

Good to know about the F3F having flotation bags as well.

Wide stance landing gears were more common than not and yes. Sumitomo built Ham Std props under licence.

 

[R Leonard]

Early F4F-3's has floatation bags as well, but they had a habit of inflating in flight, usually with unfortunate results, so they were removed.

 

[MiTasol]

Early F4F-3's has floatation bags as well, but they had a habit of inflating in flight, usually with unfortunate results, so they were removed.

Murphy's Law of unintended consequences strikes again.

The ones in the A6M series were totally internal so this was never a problem on them.

 

[Shortround6]

Murphy's Law of unintended consequences strikes again.

The ones in the A6M series were totally internal so this was never a problem on them.

A Blackburn Shark with floats flipped on landing and was towed, upside down, floats out of the water a number of miles back to base.
That is pretty good built in flotation.

 

[Frog]

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