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

[FLYBOYJ]

The Wing Spas (fore and aft) are extruded, not cap and shear web rivet assemblies...

Very correct! Have you seen this?

Design Analysis of the Zeke 32 (Hamp - Mitsubishi A6M3)

 

[drgondog]

Joe - yes - which is why I made the comment..

 

[FLYBOYJ]

Joe - yes - which is why I made the comment..

 

[GregP]

Yes, we have a Betty bomber that is displayed in "as found" condition. It is restorable, but would be a 20 year project I think. We have all the main parts. The tail is separated from the fuselage, but we have it all.

As far as the Bell YP-59A goes, we are closing in on it and will dislpay it again this year. I am on a team of 3 guys and there is another team of 1 - 2 guys depending on the weekend. My team built a new sliding canopy from scratch and we are now finishing the windscreen area. If you look closely at the windscreen this year, we have scratch-made the entire thing except for the basic windscreen frame, and we DID make the top center portion of that from scrath, too. The actual front windscreen material is about 2.5 - 3.0 inches thick and we are just completing the sheet metal that surrounds it. The piece that has been on the plane for the last 20 years does not really fit and we decided to make one that does. It is about 90% finished and the shape is correct.

The engines are in it and ready to run, a fire system that was never there in stock form has been fitted, the cockpit is very nearly complete except for the instrument panel (we are waiting on Steve Hinton to make it after he decides what radios and such to install), and we have jacked up the aircraft and have swung the gear ... everything works. When Steve completes the instrument panel, we'll call a fuel truck, fill the tanks and crank it up.

The main things left to complete other than the instrument panel are the wing gap seals (75+% completed), fitting the ailerons (the starboard aileron does not really fit and we may have to make one or make new mounting flanges for the existing aileron), and the last finishing touches on the cockpit windscreen and canopy. Once that is all done, all we have to do is roll it into Fighter Rebuilders and have the A&P's go through the aircraft and systems to ensure we did quality work, fill it with fuel, and do a flight test program. We are about $50,000 short of funds for the fight test program. We
ll probably burn 40% of that on the ground and the rest in flight test. Once done, it joins the list of airworthy planes ready for flight. Likely it will stay in California and fly at our airshow each year as well as perhaps some close airshows, such as March AFB or Edwards AFB. They aren't far and the YP-59A, as short-ranged as it is, can make it to both of those easily.

We only have three engines and, with modern bearings, we think it chould be able to fly for quite awhile since the yearly flight time will be quite low.

 

[FLYBOYJ]

Greg - are you using the original engines?

 

[GregP]

The three XP-59A's used the GE-IA engine with 1200 or so pounds of thrust. It was basically a British Whittle engine made in the USA to English drawings. We are using the next engine, the GE I-16, which was fitted to the the YP-59A's (our plane is the 7th YP-59A and the 10th overall airframe if you count the three XP-59A's) at some point. We THINK the original engines in the YP-59A were GE-IA's and the I-16's were fitted later, so we may have the original engines or not ... the history is hard to dig out entirely. They made 66 airframes: 3 XP-59A's, 13 YP-59A's, 20 P-59A's, and 30 P-59B's. There are about 6 airfrmes left and one is over at March AFB, quite close to us actually

We have the basic data on it, but the original fitment is somehwat of a question. We KNOW it ended up with GE I-16's so maybe yes ... maybe no is the best answer I can give right now. Our I-16's were overhauled in the 1990's and made 1,650 or so pounds of thrust on the test stand at that time.

If the museum agrees, we'd like to put the third I-16 in the Ryan Fireball and get it flying.

 

[FLYBOYJ]

will a stock J33 fit?

 

[ColesAircraft]

Hi Ron Cole,

I talked with the Museum staff this past weekend about the Mitsubishi J2M Raiden and said that when I was finished with the Bell YP-59A we are restoring to flight status, I'd like to take a crack at the Raiden. I spoke both to Ed Maloney (our founder) and to the Board Chairman Byian Boyer. Brian said the Raiden was not on the list at this time because the corrosion is bad enough to warrant full disassenbly and inspection ... and the estimated restoration cost would run between $4M and $5M ... and that was not in the cards at this time.

Ed said the engine is pretty much of a basket case, and that installing an American radial would not do because the engine had really long propeller shaft and American radials don't match that feature ... so we'd pretty much have to resurrect the Japanese raidal, a Mitsubishi MK4R-A Kasei 23a. We MIGHT be able to get Mitsubishi to help ... and maybe not.

So ... probably we'll work on another plane. I'll try for a restoration to flight status of our Ryan Fireball ... we'll see, won't we?

Just FYI.

Thanks for that information, and taking the matter up at PoF. I've known Ed for decades - he was a Charter member of my JII Clearinghouse back in the '80s - but lost touch years ago.

I've heard a lot about the Raiden from folks there over the years, like Steve Hinton, and pretty much heard the same story. I understand that there has to be a commercial element in the decisions made by the board regarding what gets financed and what doesn't, which makes possible a lot of restorations and preservations that would otherwise never happen - so I'm not critical of it. But there is probably no way the Raiden could be made airworthy again, and if it were done it would likely be at the expense of much of its original equipment. What makes the Raiden such a charm is that she's so original. Ed had to replace the wingtip light covers, some of the canopy plex, tires, and fabric covering - but otherwise this aircraft is as flown in 1945 by the Japanese Navy. I could have hit someone with a spray can in '87 for over-painting the cockpit - but much of the original colors are still there. It was amazing to poke my head behind the pilot's seat to view the inside of the fuselage, and see the original factory stenciling.

I do think something short of a restoration needs to be done, though; something practical that doesn't cost a fortune but maintains the aircraft's displayability. The landing gear will go one day - at the very least. I work for a Japanese model kit company that is producing a new kit of the Raiden. Their CEO is a wonderful man who buys a lot of WW2 aircraft items from me as well. Maybe I could speak with him about it. I communicate with him regularly and I'll be seeing him in person this August.

Please feel free to contact me if this strikes a chord.


Ron Cole

 

[GregP]

Joe, the GE I-16 was later designated as the J-31 and it fits. I don't think the J-33 would fit because the I-16 is 40 inches in diameter and weighs 750 pounds. The J-33 is about 1,800 pounds in weight and I believe it is too big to fit. However, if you have or know if a stock J-33, let me know and I'll pass on the info to Steve Hinton! We definitely have planes that use the J-33!

If you know where a couple of Derewnt 5's are that would be cool! We have a Gloster Meteor ... but no engines ...

Ron, if yiou can find some sponsor for the Raiden, that would be great! I'm sure we'd love to restore it ... the main issue is cost ... and we'd have to get help from Mitsubishi for the engine and maybe the spars and longerons.

 

[davparlr]

I am not an expert here, all I have is opinion. But first I must say that statements AND challenges make for much better understandings. There are many bona fide experts on various aircraft from various countries and all have been questioned by fellow members to the benefit of all. We also have non bona fide experts here. Do not think a question is a personal challenge but rather a request for supporting data.

My opinion is that the Zero is indeed an amazing and beautiful aircraft. It was a bit slow but could really turn and in the early part of the war fighting was still maneuvering and energy management (speed and altitude) fighting concept was poorly, if at all, understood. Also, in 1939, how many aircraft had armor or self sealing tanks? In fact, at the start of 1942, I don't think the F4F-3 had either. Oh, and the range.

I don't think it's fair to say that this philosophy was imposed upon Japan due to an inability of Japanese industry to manufacture powerful aircraft engines. The Nakajima Sakae that powered the Zero possessed an impressive power to weight ratio (much as their modern automotive counterparts do). In fact when restorers of Zeros today replace the Sakae with the best American-made replacement engines they can find, the performance of the aircraft suffers dramatically. There is simply no non-Japanese radial engine in the world capable of replacing the original - anywhere, by any manufacturer or nation.

I am not sure of your argument here. You seem to be sitting on a tack here I miss the point, to make a pun. Most of the people here respect the technical accomplishment with the Zero and do not subscribe to the trend that Japanese were not advanced in 1939. Indeed, their torpedo planes were the best and their torpedoes would have been the envy of the world if they only knew. And this is only an example. However, I suspect the Sakae engine was state-of-the-art and similar to other engines in this era. I suspect that an R-1830 mounted with similar accessories would most likely perform similarly. This doesn't mean that the Sakae was any less impressive.

The Navy pilots resented that the Army planners hadn't placed more emphasis on range, which left the Navy to fight alone in many circumstances.

This is an interesting statement. Aren't most Navy pilots, flying off carriers, are there because land based planes cannot reach the target? I would expect they would be use to it. Also, I cannot imagine US Navy pilots admitting they needed the Army pilots for anything. I am not saying you are wrong, it is just strange.

The Japanese would have built P-40s??? Sakai expressed contempt for the P-40, as did most Japanese pilots who met them in combat. The Japanese Army actually operated a small unit of captured P-40s they obtained intact from the Philippines, but it was a very short lived experiment. I think it's a beautiful plane, but it wasn't an aircraft, or the embodiment of a concept, that the Japanese wanted to emulate.

I agree with your statement. However, I suspect, that since the P-40B was faster than the Zero and the F4F, and would out dive the zero, and was easier to maneuver than the zero at high speeds, that the main reason for the disdain of the Japanese was due to inexperience, and/or improper techniques of the AAF pilots confronted early in the war. The US Navy pilots would have had more time and more experience and performed much better in their F4Fs. Also, early in the war, Japanese pilots were very good.

The Sakae series of radials were amazing pieces of technology in terms of their weight in relation to their power output.

It was basically state of the art, so why is that amazing? Was it because it was made by the Japanese? I would say it is impressive, but not amazing.

.

Thus . . . today it's essentially irreplaceable and the performance of Zeros equipped with lesser (heavier) powerplants see their performance suffer.

How? Since it is admitted that max performance would not be featured then what would be missed, roll rate? Nah. Turn rate? Nah. Climb? Maybe a bit, maybe not. Acceleration? A bit. However the aircraft would still have nice power to weight ratio and unless compared side by side, would probably not be noticed. And finding a mechanic and parts would be a lot easier.

Now, it may be that the "suffered dramatically" opinion that originated with Nobuo Harada took into consideration fuel consumption - something that obviously would not play any role in an air show hop.

Is there data on fuel consumption in say lbs fuel/hp/hr?

It's also worth noting, since we're invoking pilot perspectives, that Japanese pilots during WW2 strongly preferred the lighter and less powerful A6M2-21 to any other later variant. They were coveted by units and their best pilots as their numbers dwindled. I've never heard similar claims from Luftwaffe pilots regarding the 'Emil'.

I have heard that some preferred the F to the heavier G. Also, some Navy pilots preferred the lighter F4F-3 to the -4 and some pilots preferred the lighter P-51B to the –D.

Every Zero owner I know in the world goes to extreme lengths to try to find and restore an original Sakae for reasons other than originality - it's a requirement to make a Zero fly like a Zero!

I don't think they would ever see it unless they maxed it out, which you said they wouldn'
t do. Also, a 1962 Corvette with the original 327 engine is far more valuable that nice 62 with a hotter 350.

It was the first aircraft in the world, it is believed, to have incorporated its duraluminum skin as a structural member. Before that, aircraft were structurally designed on paper to withstand certain forces, then covered to be aerodynamic - but that's how far the designers went to keep the Zero light. It doesn't suffer added weight well, in any form.

The Northrop Alpha, which flew in 1930, used stressed-skin design and its wing design was later used on the DC-2/3. I do not think the Junkers J.1 was a stressed-skin design but rather a metal frame with a metal skin, but not stressed.

that the West was taking something from them that it had no right to take when it painted their airplanes - usually flaming at the guns of a P-40 - or restored a Zero for primarily Western air shows.

This is a common complaint by all non-US aficionados. I don't know the answer. I guess most of the customers are Americans. Too bad, especially on the "Dogfight" show.

3) Japanese used combat flaps in their later fighters apparently with good results. However no other nation used them . Do you have any explanation?

Some planes may have a "dogfight" setting on their flaps but any pilot could use them if they know what they were doing. Some reports I have heard tell of P-51 pilots lowering flaps in a turning fight.

 

[davparlr]

Joe, the GE I-16 was later designated as the J-31 and it fits. I don't think the J-33 would fit because the I-16 is 40 inches in diameter and weighs 750 pounds. The J-33 is about 1,800 pounds in weight and I believe it is too big to fit. However, if you have or know if a stock J-33, let me know and I'll pass on the info to Steve Hinton! We definitely have planes that use the J-33!

If you know where a couple of Derewnt 5's are that would be cool! We have a Gloster Meteor ... but no engines ...

Ron, if yiou can find some sponsor for the Raiden, that would be great! I'm sure we'd love to restore it ... the main issue is cost ... and we'd have to get help from Mitsubishi for the engine and maybe the spars and longerons.

Doesn't the J-33 fill up the fuselage of a T-33? I think it is way too big.

 

[GregP]

Yup, pretty much fills it up. And is way fun to fly.

 

[drgondog]

I wasn't jabbing your comment Joe. A lot of ships used cap and shear web for bulkheads and spars - I went though the entire package to look at the design approach and found it sound and conventional by standards of 40-60's with respect to low/medium speed a/c.

What was somewhat novel in the early 40's was dimpling and countersinking skins for flush rivets in regions where airflow/boundary layer properties were crucial - some examples that come to mind include the 109 and 51 wings and nose (IIRC for the 109). I didn't really look at the Hamp report closely enough for that approach to leading edge on the wings.

Also the use of aluminum skins as shear panels should be obvious to Japanese engineers - as the approach was introduced in the 30's and once again serves very well except when a.) conventional methods don't work for either ultra performance or b.) when combining high performance/low labor such as chem milled or composites structural approach.

I still scratch my head when I hear comments regarding low quality of Japanese engineering. 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.

 

[davparlr]

Yup, pretty much fills it up. And is way fun to fly.

An AF bud of mine flew AT-33s in gunnery training back in early 70s (he was going to OV-10s). He said one had to be careful not to get the castering nosewheel cocked. Also, with its wing tip tanks, it liked to continue to roll once started. Apparently there was line painted over the nose with a string attached to aid in gunnery alignment. Sometimes its the simple things that work. I would imagine that huge centrifugal compressor would take a bit of time to spool up. He also said the instruments seemed to be scattered all over the place with no rhyme nor reason. I would have liked to have flown one just for the history aspects, but I am glad I got to train in the T-38.

I am still planning on coming to see you and tour your facilities. However, with grandkids involved in sports on Saturdays, it tough fitting it in.

 

[FLYBOYJ]

I wasn't jabbing your comment Joe.

No worries Bill, I was just being a bit goofy (nothing new).

 

[GregP]

Hi davparlr,

You are certainly welcome out any time. I am there on Saturdays in the restoration hangar.

Time is a luxury and I am either lucky or unlucky depending on your definition in that I am alone, so my time is for whatever I want it to be for. I choose to restore old warbirds on Saturdays. Anyway, if you can fit it in, just ask for Greg in the restoration hangar any Satuday except to the weekend after next ... our airshow is that weekend and we'll all be working the airshow. I'll be taking parking fees in the RV parking area. The view from there is great, so at least I won't miss the show!

Due to federal budget cutbakcs we don't have any military participation this year, but our heritage flight will include a private F-4 Phantom! Looking forward to that one! Old Double Ugly is back for an encore! I hope he plugs in afterburbner and at least does a spirited climbout at the end!

Mwanhile, most of the show will be WWII warbirds along with Sean Tucker and Rob Harrison. The Horsemen will fly again this year and their mounts will be our two P-51's with Steve Hinton in the middle in our P-38!

 

[ColesAircraft]

davparlr wrote: "It was basically state of the art, so why is that amazing? Was it because it was made by the Japanese? I would say it is impressive, but not amazing."

If I wrote that the P-51 was "amazing" would I be taken to task for it?

 

[davparlr]

davparlr wrote: "It was basically state of the art, so why is that amazing? Was it because it was made by the Japanese? I would say it is impressive, but not amazing."

If I wrote that the P-51 was "amazing" would I be taken to task for it?

If you would say that the P-51s ability to fly 600 miles, fight the enemy competitively over their homeland and then fly 600 mile home is amazing, I would not take you to task for that. If you said that the P-51 was an amazing dogfighter, I would. It was a good one but was not significantly better than the other fighters and was not amazing. By the way, I would not take you to task if you made the same amazing statement about the Zero's ability to fly long distance and fight competitively. There were few aircraft that could approach this capability.

From an engine standpoint, I think the P&W R2800-57 engine, with the ability to provide 2800 hp flat rated up to 33k was amazing. The Sakae was a good engine but not significantly lighter or smaller or more powerful or more efficient than contemporary engines.

 

[FLYBOYJ]

I still scratch my head when I hear comments regarding low quality of Japanese engineering. 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.

You nailed it Bill. They gave "the customer" exactly what they asked for.

 

[ColesAircraft]

If you would say that the P-51s ability to fly 600 miles, fight the enemy competitively over their homeland and then fly 600 mile home is amazing, I would not take you to task for that. If you said that the P-51 was an amazing dogfighter, I would. It was a good one but was not significantly better than the other fighters and was not amazing. By the way, I would not take you to task if you made the same amazing statement about the Zero's ability to fly long distance and fight competitively. There were few aircraft that could approach this capability.

From an engine standpoint, I think the P&W R2800-57 engine, with the ability to provide 2800 hp flat rated up to 33k was amazing. The Sakae was a good engine but not significantly lighter or smaller or more powerful or more efficient than contemporary engines.

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