Improve That Design: How Aircraft Could Have Been Made Better

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FLYBOYJ said:
I don't know if you know anything about weight and balance but you can't effectively start adding weight, (be it ballast or armor plate) unless that weight can be installed along the "arm" where the C/G can be maintained within the C/G envelope and can be supported structurally within the aircraft. The other key is to install that ballast in a place within the arm so you use the least amount of weight possible. Using fuel to keep and aircraft within a C/G envelope is dangerous unless there is a method to burn off or transfer fuel in such a manner that the C/G envelope can be maintained. You also have to consider what is going to happen to the C/G after any armament is expelled.
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I get that there's only so much that you can do in that regard, and I get that I was acting like it's way simpler to fix CoG issues than it actually is. But generally, when you're forced to add ballast to an engineering project that desires low weight, you need to ask if the performance gains being made are worth it. IF the Ha-140 were a mature engine, and had acceptable reliability, then maybe it would have been worth the risk, as a 1,500hp engine with low frontal area. But it was not mature, and as such, there was little room for pilots to USE that extra power even if the aircraft DIDN'T need to make massive sacrifices in order to house the engine. So in practice, the only real benefit of the Ki-61-II was in maximum level speed, which was still only decent, and it suffered in maneuverability, reliability, and received little benefit to climb rate, due to the increase in weight balancing out the power gains.

The Ki-100 is the direction a Hien upgrade should have been pushed towards all along: while the Kinsei wasn't a perfect engine either, and the frontal area was larger, the weight was more or less comparable to that of the Ha-40 engine, but without the need for a liquid cooling system. Even if we assume a far less mature variant of the Kinsei that was only rated for 1,200hp, the cost in maximum speed would be compensated for by better serviceability and by greater development potential. Quite simply put, Japan should have simply cut its losses with liquid cooled aircraft engines, as the difference in power to weight and frontal area between types was proving to be much smaller than the difference in Japan's ability to manufacture one or the other at a given rated power.

I suppose if I'm going to keep babbling on about Japanese aircraft, I should probably argue that they should have placed a greater priority of placing at least 1 heavy machine gun on the zero by the next major production variant, the Model 32 (A6M3). Pilots had found the ballistics of the current 20mm cannon unwieldy, but it was also apparent that rifle caliber machine guns were woefully underequipped to deal with USN aircraft. I can't find anything suggesting the Type 3 Aircraft machine gun would be available at this time, but in theory, the Navy could have requested a naval variant of the Ho-103 as a stop gap if the Type 3 couldn't be adapted. Yes, these are much heavier guns, on a plane that is meant to be lightweight, but a single Ho-103 or Type 3 mounted in the cowling would offer superior damage against protected aircraft than a pair of rifle caliber machine guns. Depending on when this was implemented, it could arguably be of greater importance than applying armor plate to the Zero, if only because making use of better pilot protection would requires a complete overhaul of the Japanese military's culture and view of the value of a serviceman's life: it doesn't matter if they survive to bail out or ditch, no one will be coming to save them.



I have no idea where I'm even going with this anymore...
 
As you have guessed ballast location can be a real problem.

The simple solution for nose heavy is to fit the ballast as far back as possible meaning on the rear spar of the fin (or inside the rear spar of the fin if a tubular frame - a common fix on aerobatic aircraft) as that requires the absolute minimum of additional weight but it is not that simple.

Having the ballast weight that far back is great if your actual operating weight or CG only changes a small amount but can quickly get problematic if you have a large weight reduction from fuel and ammo actually on or near the CG. Then the weight needs to be close enough to the CG to keep it in limits and simultaneously far enough away to the CG to keep it in limits.

Modern airliners have it easy. On one hand the CG moves forward as the fuel in the wing burns off as gravity moves the fuel inboard and forward leaving the outer aft portion of the wing empty. To compensate many have ballast tanks in the tail that they can use to move the CG back and forth as required - especially now that load control software takes the calculations out of the airframe drivers hands to optimise/minimise drag.
 
Spindash64 said:
I get that there's only so much that you can do in that regard, and I get that I was acting like it's way simpler to fix CoG issues than it actually is. But generally, when you're forced to add ballast to an engineering project that desires low weight, you need to ask if the performance gains being made are worth it.
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Aside from the what you're saying and the poor performance of this engine, there's still a lot of thought and consideration when placing ballast on an aircraft. In some cases ballast placement and the few extra pounds that came along with it made the aircraft perform better. If I recall, the Spitfire Mk IX had almost 90 pounds of ballast in the tail. Now if you can make armor plate work for you as ballast, that's a plus, but it like hoping planets and stars align in your favor.
 
Yeah, in hindsight that was me talking about of my ass. I DO Still argue that, in the case of the Ki-61-II, it was among the little things that added up as red flags to say "This new engine ain't it, chief". If water injection had been developed for the engine, then maybe the available power could have been enough to actually improve the climb rate. But as it stands, even the Ha-40 was a bit temperamental: this engine was simply never going to be worth the effort. Even the Kasei would have been a better choice, despite it ALSO being somewhat temperamental and likely requiring significant ballast to balance it out again
 
Spindash64 said:
Yeah, in hindsight that was me talking about of my ass. I DO Still argue that, in the case of the Ki-61-II, it was among the little things that added up as red flags to say "This new engine ain't it, chief". If water injection had been developed for the engine, then maybe the available power could have been enough to actually improve the climb rate. But as it stands, even the Ha-40 was a bit temperamental: this engine was simply never going to be worth the effort. Even the Kasei would have been a better choice, despite it ALSO being somewhat temperamental and likely requiring significant ballast to balance it out again
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No, it's all good and you probably have valid points about the Ki-61.
 
Spindash64 said:
Depending on when this was implemented, it could arguably be of greater importance than applying armor plate to the Zero, if only because making use of better pilot protection would requires a complete overhaul of the Japanese military's culture and view of the value of a serviceman's life: it doesn't matter if they survive to bail out or ditch, no one will be coming to save them.
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Well, there is that point of view, but the other view is that the Japanese did apply better protection to their aircraft, the Allies just did it sooner. At the time of Pearl Harbor, not all the navy's F4Fs had self-sealing tanks. The early models rolled off the production line without them. Later models of A6M did have better protection, including self-sealing tanks. The problem/consideration (depending on which end of the telescope you wanna look down) was the specification to which the A6M was built versus the engines available. Nakajima deemed the specs too difficult and didn't even try, although the Ki-43 was a good fighter with similar performance, if not a naval aircraft. Because it took so long, as you know, to produce the A6M's replacement it was kept in service and upgraded beyond what was expected and beyond its useful life, so adding extra weight was definitely going to stifle its remarkable manoeuvrability while maintaining the performance it had with given engines.

Not being saved by their own people wasn't necessarily something the Japanese wanted, but it didn't really have the resources to do so, particularly as the war wore on and they began to lose territory - not every Japanese pilot was a Kamikaze, they did expect to survive, after all, why issue them with parachutes if they didn't?
 
nuuumannn said:
Well, there is that point of view, but the other view is that the Japanese did apply better protection to their aircraft, the Allies just did it sooner. At the time of Pearl Harbor, not all the navy's F4Fs had self-sealing tanks. The early models rolled off the production line without them. Later models of A6M did have better protection, including self-sealing tanks. The problem/consideration (depending on which end of the telescope you wanna look down) was the specification to which the A6M was built versus the engines available. Nakajima deemed the specs too difficult and didn't even try, although the Ki-43 was a good fighter with similar performance, if not a naval aircraft. Because it took so long, as you know, to produce the A6M's replacement it was kept in service and upgraded beyond what was expected and beyond its useful life, so adding extra weight was definitely going to stifle its remarkable manoeuvrability while maintaining the performance it had with given engines.

Not being saved by their own people wasn't necessarily something the Japanese wanted, but it didn't really have the resources to do so, particularly as the war wore on and they began to lose territory - not every Japanese pilot was a Kamikaze, they did expect to survive, after all, why issue them with parachutes if they didn't?
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I suspect to a certain extent that we are still victims of ww2 propaganda. The A6M had a built in flotation system our aircraft did not but the pilot/crew had a life jacket or life raft
 
MiTasol said:
I suspect to a certain extent that we are still victims of ww2 propaganda. The A6M had a built in flotation system our aircraft did not but the pilot/crew had a life jacket or life raft
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Flotation bags were more of an inter-war thing for the RN/USN. Possibly an effort to save money back then by rescuing the aircraft. Although early F4Fs seem to have had them.

Warbird Information Exchange • View topic - Aircraft Emergency Flotation Bags ...

www.warbirdinformationexchange.org www.warbirdinformationexchange.org
 
Coming back to Kawasaki, one possibility is to completely skip even the Ki-61-I and build a Ki-100 analogue from 1942. From late 1941 or early 1942, Mitsubishi were producing the Kinsei 54 for the D3A2 or the H6K5 with 1200 hp at 3000m or 1100 hp at 6200m both at 2500 rpm and with 1300 hp at 2600 rpm available for take off. By 1943, a Ha 112 II of a Ki-46 III gave 1500 hp for take off with 1350 hp at 2000m and 1250 hp at 5800m, all at 2600 rpm.

I don't know when the Ha 112 II (Kinsei 60 series) with an extra bearing and direct fuel injection became available in quantity. Wikipedia says that the Ki-46-III first flew in December 1942. However, it seems that only 10 were produced during 1943 (see Login) and the Ki-46 II was kept in production in parallel throughout 1943. I suspect that this relates to the story that Bosch never provided Japan with the machine tools to make the fuel injection system for the DB 601. The result was that Kawasaki designed its own system for the Ha-40 which was unreliable while Mitsubishi reverse engineered the Bosch system for the Aichi Atsuta. However, I think that I read somewhere that at least initially each Mitsubishi system was essentially hand made rather than mass produced. Mitsubishi thus had the ability to build fairly reliable fuel injection systems for other engines including the Kinsei and Kasei but could not produce them quickly in 1943.
 
nuuumannn said:
Well, there is that point of view, but the other view is that the Japanese did apply better protection to their aircraft, the Allies just did it sooner. At the time of Pearl Harbor, not all the navy's F4Fs had self-sealing tanks. The early models rolled off the production line without them. Later models of A6M did have better protection, including self-sealing tanks. The problem/consideration (depending on which end of the telescope you wanna look down) was the specification to which the A6M was built versus the engines available. Nakajima deemed the specs too difficult and didn't even try, although the Ki-43 was a good fighter with similar performance, if not a naval aircraft. Because it took so long, as you know, to produce the A6M's replacement it was kept in service and upgraded beyond what was expected and beyond its useful life, so adding extra weight was definitely going to stifle its remarkable manoeuvrability while maintaining the performance it had with given engines.

Not being saved by their own people wasn't necessarily something the Japanese wanted, but it didn't really have the resources to do so, particularly as the war wore on and they began to lose territory - not every Japanese pilot was a Kamikaze, they did expect to survive, after all, why issue them with parachutes if they didn't?
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That's certainly correct, but the Japanese were still a bit too slow to recognize the value of a single pilot. The Armor plating and lack of self-sealing fuel tanks weren't the main problem: they were A concern, but as you mentioned, these weren't entirely standard issue at the time of the Zero's debut, and self-sealing fuel tanks compromise internal fuel storage space, limiting range. The larger problem was, again, in doctrine. This is more noticeable with the Japanese army (the infantry specifically), which was downright verbally and emotionally abusive. The Navy, in comparison, was far better at treating its men as human, but they were still prey to the idea that, for a country with high population density and limited resources, it was better to not risk spending all of your resources on them.

On paper, that made sense at the time, but what eventually became clear is that a pilot with combat experience is worth far more than an aircraft, especially pilots like those of the IJN pre Midway. Their mistakes didn't really become apparent in this regard until after Midway, where they doubled down and sent pilots of rapidly degrading quality to the front lines with minimal training in an attempt to take the load off their few surviving pilots. Instead, what they should have done is what the Allies had started doing, which is rotating pilots back home after a certain number of sorties to work as instructors and give "fresh" combat advice to new pilots. I can't fault the Japanese on this entirely, as the Germans made the same mistake. It just became more noticable more quickly with Japan due to Midway decimating much of their naval air experience, meaning they had far less room for error.

That's why I'm arguing that they would have been better served by attempting to fit a better machine gun to the Zeros earlier: the Ho-103 was roughly twice the weight of the Type 97 aircraft machine gun, but fired rounds with more than triple the mass. The RoF while synchronized was unfortunately only around 60-70% that of a synchronized Type 97 (400rpm vs 600-700), but the math still works out so that the Ho-103 will have comparable "power" in terms of kinetic energy of a ball round times rate of fire, to a pair of synchronized 97s. The larger 12.7mm rounds can also carry much greater incendiary, explosive, or armor piercing effect, while the rifle caliber rounds will be much less effective against not only components such as fuel tanks or the engine, but will have even less effect if hitting the wings or rear fuselage.

I'm not phrasing it very well, but I think you understand my point: Rifle caliber machine guns just aren't worth it in 1942.
 
Spindash64 said:
That's certainly correct, but the Japanese were still a bit too slow to recognize the value of a single pilot. The Armor plating and lack of self-sealing fuel tanks weren't the main problem: they were A concern, but as you mentioned, these weren't entirely standard issue at the time of the Zero's debut, and self-sealing fuel tanks compromise internal fuel storage space, limiting range. The larger problem was, again, in doctrine. This is more noticeable with the Japanese army (the infantry specifically), which was downright verbally and emotionally abusive. The Navy, in comparison, was far better at treating its men as human, but they were still prey to the idea that, for a country with high population density and limited resources, it was better to not risk spending all of your resources on them.
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Yup, and these are good points, Spindash, for the reasons you mentioned, and I certainly don't wish to go into the Japanese warrior culture too deeply, but, and this was mentioned by MiTasol in his post, the Zero was engineered with manoeuvrability in mind, so was supposed to be able to get itself out of trouble before the enemy could get a bead on it, but if it did get shot down a modicum of protection for the pilot in case he was over water was provided, the floatation bags. Here's what I mean, see the picture below: To get into the cockpit the pilot presses wee buttons next to these pegs, which pop out from the fuselage, from where they sit flush with the outer skin. This enables the pilot to access the cockpit without standing on the wing and buckling its thin skin. On the inside end of the spring loaded pegs is a mushroom shaped head, which prevents the pegs from puncturing the floatation bag in its inflating state, once it inflates in the water, to enable the pilot to get out. Obviously he's not gonna be worrying too much about the delicate wing outer skin, but those pegs in their retracted state won't puncture the inflating floatation bag, giving the pilot a precious few seconds longer to get out of the sinking aeroplane. That's care and consideration right there.

51235003826_64cd98dffa_b.jpg
NX712Z 12

Sure, the Japanese were slow to embody further protective measures into their aircraft compared to the Allies. Their philosophy was akin to that of the battlecruiser, speed (and manoeuvrability in this specific case) over armour plating, to their detriment of course, but let's consider their logic first before we rush to say they didn't care so much for the common pilot. This was their philosophy and until the Allies got wise, it was working for them. When the aircraft that the Japanese designed before Pearl were designed, very few, if any foreign fighters had armour and self-sealing tanks applied from the outset as they were designed. Most aircraft had these things added following combat experience. The Allies learned fast that they were necessary, but aircrews were lost learning those lessons (The US military had British aircrew lose their lives in combat so they could learn from what these things offered, of course ;) ).

The Japanese took longer, but once the shooting started, that stuff came as standard on new designs. The Ki-44, the Ki-84, the J2M and A7M - the latter two designed by Horikoshi, responsible for the A6M, all had armour plating applied from the outset, and of course the A7M was designed to succeed the A6M in service. As mentioned, the Zero was gonna be hampered by them regardless because of its design philosophy, so the push was not so great because for the first year of the war in the Pacific it was doing pretty good for itself and back in the war offices at home, the A7M was being promised within months, so modification wasn't strictly urgent. Why bother, when reasons mentioned earlier? While the Japanese regard for human life was different to ours, claiming the Japanese didn't care about its pilots doesn't hold water when logical evidence is applied, but I understand your point.


Spindash64 said:
'm not phrasing it very well, but I think you understand my point: Rifle caliber machine guns just aren't worth it in 1942.
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Nope, you made your point clearly and concisely, so hat's off to you, and I agree with you on this. :thumbright:
 
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