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Gaston444
08-01-2009, 01:46 AM
Hello everyone!

After my January 2009 letter in "Model Aircraft Monthly", where the Nakajima short-tail "theory" was more-or-less launched, further research and a much longer letter will now appear in this August's issue of "Model Aircraft Monthly".

This will include this time comparative side-by-side profile drawings made by me, with all features, of the Mitsubishi and Nakajima-built Model 52 Zeroes, plus several supporting photos.

These will be the first truly accurate Zero Model 52 profile drawings, in general outline, for EITHER manufacturers... Previous drawings (probably all based on the same inaccurate factory General Arrangement drawings) having severe problems centering usually around the canopy depth to fuselage depth ratio, canopy lenght or extremities position, and completely wrong cowling radiuses... (Fortunately, the new 1/48th Tamiya Model 52 kit matches my drawings fairly well, and not so well its own factory-based decal instructions drawings: They measured the real thing, and it paid off...)

The August 2009 issue of "Model Aircraft Monthly" will mark the very first time the 8" shorter Nakajima Model 52 is represented anywhere, perhaps since Gen. MacArthur ordered all Japanese aircraft blueprints destroyed in 1945...

Anyone who doubts there are major dimensional differences between Nakajima and Mitsubishi Zeroes has not contacted a restorer who works with original parts from BOTH manufacturers...

There are numerous discrepancies for even the Model 21, and much larger ones for the Model 52 and Model 53.

The Nakajima Model 52's tail is a massive and complete re-design, in pitch attitude, lenght, tail surfaces chord and tail surfaces design... That something so large could have completely escaped notice for 64 years defies belief, but the blueprint destruction context, and the careful "blending in" of the huge 8" shortening, do go a long way toward explaining it. Then add the absence of survivors...

When side-by-side on the same photo however, with exactly matching parallax-neutral angles (compare the canopies and tailplanes of the first two aircrafts), the effect is very far from subtle;

http://www.j-aircraft.com/jiml...5_aslitolineup_c.jpg (http://www.j-aircraft.com/jiml/a6m5_aslitolineup_c.jpg)

There is more evidence coming in the next few months, but for the moment I will simply leave it at that.

Further photo evidence covers the Model 52 from the earliest Nakajima production run to the very latest A6M7, making the short-tail Nakajima Zero the predominant production Zero(!).

Enlarged to the correct scale, the "Model Aircraft Monthly" drawings should be accurate enough to modify existing kits. Be advised that for practical reasons, due to the way the drawings were made and the original 1/144 scale, there are small panel lines errors at the base of the fin, and a few missing panel lines in the rear fuselage (this does not affect the outline).

For me, making the drawings and modifying the kits at the same time was a great help at narrowing down the lenght discrepancy more accurately, down to 203 mm (8"), 10 mm, resulting in a final overall lenght of 8.85/8.87 M for a true Nakajima-production Model 52, versus the previously assumed 9.06 M that is correct for a Mitsubishi-production Model 52.

The "Model Aircraft Monthly" letter will detail how the short-tailed Nakajima Model 52 Zero became the "lost" Zero for 64 years... It is an amazing story, and it is quite possible, even likely, that Zero designer Jiro Horikoshi knew nothing about it...

Could anyone guess what difference in handling would have resulted from this 8" shorter tail, the leading edge root of all tail surfaces being pushed back 4-5" for reduced tail leading edge sweep, and a reduced elevator maximum chord by 40 mm on an actual wartime document: 350 mm instead of 390 mm?

I have heard a Corsair pilot account of chasing a Model 52 in late 1943, which was out-rolling him from side to side several times in a dive at 400 MPH, forcing his early Corsair's ailerons into overbalance when trying to match... Doesn't sound like your typical Zero now does it? (I can provide the link to the AH discussion later)

Gaston

P.S.: For those who are wondering, yes I am aware the "Planes of Fame" Nakajima ser. #5357 is now flying with the longer Mitsubishi tail... See my analysis of numerous mismatching close-up details on wartime and 1950 post-war photos of that same aircraft's tail in the August "MAM" letter.

And hey, that obviously shorter-tailed Zero in the above photo? That IS ser.#5357... Back in 1944 when it had a short-tail...

You could not get any luckier than that: No way.

G.

Gaston444
08-01-2009, 01:46 AM
Hello everyone!

After my January 2009 letter in "Model Aircraft Monthly", where the Nakajima short-tail "theory" was more-or-less launched, further research and a much longer letter will now appear in this August's issue of "Model Aircraft Monthly".

This will include this time comparative side-by-side profile drawings made by me, with all features, of the Mitsubishi and Nakajima-built Model 52 Zeroes, plus several supporting photos.

These will be the first truly accurate Zero Model 52 profile drawings, in general outline, for EITHER manufacturers... Previous drawings (probably all based on the same inaccurate factory General Arrangement drawings) having severe problems centering usually around the canopy depth to fuselage depth ratio, canopy lenght or extremities position, and completely wrong cowling radiuses... (Fortunately, the new 1/48th Tamiya Model 52 kit matches my drawings fairly well, and not so well its own factory-based decal instructions drawings: They measured the real thing, and it paid off...)

The August 2009 issue of "Model Aircraft Monthly" will mark the very first time the 8" shorter Nakajima Model 52 is represented anywhere, perhaps since Gen. MacArthur ordered all Japanese aircraft blueprints destroyed in 1945...

Anyone who doubts there are major dimensional differences between Nakajima and Mitsubishi Zeroes has not contacted a restorer who works with original parts from BOTH manufacturers...

There are numerous discrepancies for even the Model 21, and much larger ones for the Model 52 and Model 53.

The Nakajima Model 52's tail is a massive and complete re-design, in pitch attitude, lenght, tail surfaces chord and tail surfaces design... That something so large could have completely escaped notice for 64 years defies belief, but the blueprint destruction context, and the careful "blending in" of the huge 8" shortening, do go a long way toward explaining it. Then add the absence of survivors...

When side-by-side on the same photo however, with exactly matching parallax-neutral angles (compare the canopies and tailplanes of the first two aircrafts), the effect is very far from subtle;

http://www.j-aircraft.com/jiml...5_aslitolineup_c.jpg (http://www.j-aircraft.com/jiml/a6m5_aslitolineup_c.jpg)

There is more evidence coming in the next few months, but for the moment I will simply leave it at that.

Further photo evidence covers the Model 52 from the earliest Nakajima production run to the very latest A6M7, making the short-tail Nakajima Zero the predominant production Zero(!).

Enlarged to the correct scale, the "Model Aircraft Monthly" drawings should be accurate enough to modify existing kits. Be advised that for practical reasons, due to the way the drawings were made and the original 1/144 scale, there are small panel lines errors at the base of the fin, and a few missing panel lines in the rear fuselage (this does not affect the outline).

For me, making the drawings and modifying the kits at the same time was a great help at narrowing down the lenght discrepancy more accurately, down to 203 mm (8"), 10 mm, resulting in a final overall lenght of 8.85/8.87 M for a true Nakajima-production Model 52, versus the previously assumed 9.06 M that is correct for a Mitsubishi-production Model 52.

The "Model Aircraft Monthly" letter will detail how the short-tailed Nakajima Model 52 Zero became the "lost" Zero for 64 years... It is an amazing story, and it is quite possible, even likely, that Zero designer Jiro Horikoshi knew nothing about it...

Could anyone guess what difference in handling would have resulted from this 8" shorter tail, the leading edge root of all tail surfaces being pushed back 4-5" for reduced tail leading edge sweep, and a reduced elevator maximum chord by 40 mm on an actual wartime document: 350 mm instead of 390 mm?

I have heard a Corsair pilot account of chasing a Model 52 in late 1943, which was out-rolling him from side to side several times in a dive at 400 MPH, forcing his early Corsair's ailerons into overbalance when trying to match... Doesn't sound like your typical Zero now does it? (I can provide the link to the AH discussion later)

Gaston

P.S.: For those who are wondering, yes I am aware the "Planes of Fame" Nakajima ser. #5357 is now flying with the longer Mitsubishi tail... See my analysis of numerous mismatching close-up details on wartime and 1950 post-war photos of that same aircraft's tail in the August "MAM" letter.

And hey, that obviously shorter-tailed Zero in the above photo? That IS ser.#5357... Back in 1944 when it had a short-tail...

You could not get any luckier than that: No way.

G.

Phas3e
08-01-2009, 01:57 AM
Fantastic stuff, this is why I consider MAM one of the premier aviation resources

Feathered_IV
08-01-2009, 04:28 AM
Fascinating. Thanks for bringing this up Gaston. I'll be following your research with great interest.