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#11
06-23-2013, 08:15 PM
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So, I guess what Horseback is getting at is that the USN aircraft require more trim to accelerate properly than their IJN counterparts, which is unfair/unrealistic
If anything, that has to be a problem with the IJN aircraft. Changing speed in an airplane requires a fair deal of attention to trim.  I can also imagine that part of the problem is the uber-experience of online pilots - thousands of hours of flight time with zero real deaths...Even if you run away properly they can nail you from 500+ meters (and a lot of pilots use zoom to do it from even further). 
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#12
06-23-2013, 08:20 PM
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Part of what I'm trying to do is find the best way to fly accurately or get the best out of the aircraft as the average player with TIR and the usual array of controllers would, which is (partly) why I fly the tests in cockpit. In a lot of cases, there appears to be a sort of forced parallax, where the indicators don't align, particularly in the US type artificial horizons (and all of my photos and source material show no such parallax visible, either from the pilot's seat or even from shots taken just outside the cockpit). This tends to make it harder to keep your wings level when you're trying to hold the nose down until the elevator trim can be dialed in. Generally, the in-cockpit slip ball (or T&B needle in the case of British fighters) is at least slightly in conflict with the vector much of the time and the in-cockpit 'ball' is almost always in error versus the WW vector ball during any kind of change in direction or sudden power surges. About the LaGG, I think that we have to take the altitude (approx 3000m) into account, as well as the fact that in-line engines are both more aerodynamically friendly and seem to 'rev up' more quickly. We also have to think about reputations; the later LaGGs were quite improved over the early models, but the pilots of the VVS appear to have lost faith in it the same way USAAF pilots in the Southwest Pacific lost faith in the Airacobra. At 3000m, the LaGG (66) may be closer to its best performance height than the La-5F and FN, as well as being a bit more aerodynamically refined. I think that the results at 100m and 1500m will be quite different. cheers horseback
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#13
06-23-2013, 08:46 PM
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The IJN/IJA fighters do require trim adjustments, but the adjustments are not excessive in terms of button presses and they are consistent and predictable in a way that the Corsair and Hellcat are not. This allows the fairly average IJN flyer a degree of immediate precision that the USN flyer must learn over many times more hours of practice (and if he's using button trim, he's still going to be 'behind the curve' the moment he wiggles his stick). You can add in the way that the F4U and F6F's noses drop and later rise in level (changing AOA) flight as speed increases (this is also evident in the P-47); most of us use the gunsight or some part of the cockpit framing as a reference to maintain our angle of flight, and this will add to the problems of flying with any degree of precision, especially if competing against aircraft whose trim requirements and flight qualities are best guesses derived from 70 year old documents and pilot reports. cheers horseback
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#14
06-23-2013, 09:47 PM
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As for prop speed, for most cases I use the 100% prop pitch setting because it is loosely analogous to low gear in a car; unfortunately, when I try to get a fast start from first gear in a car, I can gauge how much power to apply by feel, something that is not available to the virtual pilot, so I felt that I had to keep things fairly basic. I tried a few experiments with the Spit IX and the P-51C with the engines at both 2700 and 3000 rpm, which are included in the Spitfirepalooza and USAAF fighters charts. The Spit at 3000rpm is superior to the Spit at 2700 at all speeds, while the Mustang at 3000 will rip past the Mustang at 2800 until they reach about 510 kph indicated, at which point the Pony flying at 2700 rpm passed and reached 530 IAS almost a minute sooner (looking at the data table, the 2700rpm bird actually seems to start gaining speed faster around the 490 kph point, which is where I would suggest 'changing gears' if you have to run away from trouble). The Spit IX and the P-51 have very similar if not exactly the same engines, so I figured it would be a good comparison to work with. I created a special chart demonstrating the differences which I will attach below. I left the Germans' prop pitch, with their 'automatic transmissions', alone, but most of the other aircraft seemed to respond better to just pushing the prop pitch all the way forward at the same time you shove the throttle to the stops. In all cases, I make sure that the supercharger is in the right stage, the mixture setting is appropriate (for instance, the Soviet fighters all ran better at 80% mixture at 3050m than at 100%, while the CW-21B needed 120% mixture to keep even with the Zeke 21) and that the aircraft is trimmed for level flight at 270 kph IAS at around the suggested rpm for cruise (and that the engine is relatively cool). If someone expert in one type or another feels that he can obtain better results with different settings in a given type, I invite them to put their oar in and help out the community at large. cheers horseback
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#15
06-23-2013, 10:18 PM
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The acceleration tests I did were done in a different way. I figured there were two different things to know about my aircraft and how it accelerated. The first was acceleration at very low speed. Often if you get mixed up in a dogfight you might find yourself at stall speed, or almost stopped in some evasive maneuver. So I tested all aircraft to see what speed they could get to in a set distance, starting at zero. Once I had the speeds all aircraft could reach in a set distance from zero, then I saw what speed they reached in exactly twice that distance, so then I knew which aircraft could get away from which from almost no speed at all, and I also knew which could gain the most speed when already starting at a high speed. Both very useful in evasive maneuvers and in energy fighting. I also tested the top speeds of all aircraft both on the deck and at 5000 meters altitude, which was also very useful to know for every common aircraft flown online in popular servers. Yes, some aircraft need different trimming and other settings to get the most out of them, but that is to be expected as they were different machines manufactured thousands of miles from each other by extremely different cultures and engineers. That is why making all the aircraft behave exactly the same would be ridiculous whether it trim or any other parameter or control feature, if you do that we may as well get rid of all the aircraft in the sim except for one, we could all just fly 25lb spits. I say plug the engineering data for each aircraft into the IL2 simulator and fly what you get. Every pilot in WWII had to learn his specific aircraft, if he switched to a different one then he was set back and had to learn many things all over again. Last edited by JtD; 06-24-2013 at 04:24 AM. Reason: removed insults
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#16
06-23-2013, 10:37 PM
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On trimming the Corsair, America’s Hundred Thousand says: “The Corsair was easy to trim out for climb. Trim changes from landing gear and flap retraction were minimal, and those for speed and power changes were quite handleable. In cruise condition the airplane could be trimmed for hands and feet off flying with little trouble. Pilots almost universally rated F4U-1C and -1D trimmability as good. In a dive, as with some other US fighters, a considerable amount of rudder trim was required to zero out pedal force which was high if this was not done.” One the Hellcat’s trim characteristics, it says: “There were nose up trim changes with gear and flap retraction, though they were minimal, and the same was true of initial acceleration into climb. In general, there were substantial both directionally and laterally with speed and power changes, but tab action allowed trimming out control forces to zero except for the rudder. At low speed and high power rudder pedal force could not be trimmed out fully. Most pilots thought trimmability was generally good, though some made the following comments ‘Lack of trimmability”, Excess rudder trim change”, and “Aircraft requires excessive trim” (three pilots). It was noted that in a dive control forces could not be trimmed out quickly enough. The old Naval aviators I talked to felt without exception that the Hellcat was the easiest aircraft they ever flew off a carrier deck, prop or jet. Of course, most of these old guys were raised on farms or worked at a job demanding a fair amount of physical strength (by modern standards) so a 30lb force difference probably wasn't all that excessive by the standards of the time, especially if you could easily adjust it out with the trim tabs. To be honest, 30lbs (or a bit less than 14kg) doesn't sound like that much to me, but I spent many hours in the pool and the weight room as a younger man. In-game, trimming out these aircraft is not close to 'easy'. The point is that many of the aircraft modeled in this sim are based on reports and tests done 70 years ago, and what were called 'mild' or 'light' stick or rudder forces might seem a bit heavy to the average man today. It may not be appropriate to add (over)detailed characteristics to well understood and documented aircraft that have to compete with aircraft that are modeled on older standards that cannot be verified to match the current ones. Now if you all will excuse me, some miserable sod has released a new patch, and I have to start re-running all of the 100m tests I've done so far...  cheers horseback PS: During the early phase of my tests, I ran the trim all the way out in both directions on a number of aircraft, doing both rudder and elevator, as well as a few ailerons; it takes 80 button pushes in each direction from CENTER, or 160 button pushes from one extreme of trim offset to the other. By comparison, using the CH Quad, a tiny increment seemed to have much greater, but much less predictable results. Pick your poison. Last edited by horseback; 06-23-2013 at 10:50 PM. Reason: added Post Script
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#17
06-24-2013, 04:52 PM
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UDPSpeed and UDPGraph will let you put data on-screen while flying offline which I think could include acceleration indicator which should allow dynamic testing to see what effect you could achieve. The hardest part is setup and there were walk-thru's on that last I remember. It's like the difference between hand tools and power tools, once you got power tools they can be a pain at times but mostly tend to put a smile on your face once you get used to them.
The parallax effect is probably due to being in right-eye gunsight mode. Switch back and see, it is easier to fly most fighters in centered view. Up close it's even easier to shoot that way, with practice. Really, in-game since the start I've found the smartest thing to do before maneuver combat is to neutralize trim and avoid hard G's that lead to wingtip stalls or worse. Slip... easiest to avoid in a P-51 with mini-ball gunsight and hardest in the Spits. We NEED a slip indicator in the speedbar to replace what can be felt IRL. ---------------------------------------------------------------------------------- Back in December I thought to interface Arduino to IL-2 but first there was an MP3 module to deal with. It took over 4 months to find out that the fix is shorting 2 whisker-tiny pins on a surface-mount chip which no way I can do so now there's a new module that's got its own hangups... 115200 serial may not work well breadboarding or I dunno what else is the hangup -- I'm a programmer who can do some hardware so aware that I have my own hardware limits. This will be either GO or NO GO, I won't try another, and then on to other pursuits that have been on hold like an autopilot robot.  As it is, I think my forehead is flat and I have no hair above my ears/eyebrows. Today, after reading about trim I got a real narsty idea... the same controller that runs the stick could be made to do "smart trim", couldn't it? Or maybe not, having the nose seek to bring the stick to center after some-odd seconds might be a bad thing at times, like when you're just about to shoot! Perhaps a button, like I asked Oleg for back in 2002.
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#18
06-24-2013, 06:05 PM
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Excessive trim modeling is a very good way to keep a good aircraft's performance down in practice while still allowing it to achieve its accepted performance figures; the historical record says quite clearly that the Corsair, the Mustang, the P-47 and the Hellcat were 'easily trimmed', specifically in reference to the earlier US fighters like the Wildcat, P-39 and particularly the P-40, all of which enjoy relatively similar (and easy) trim models in the game compared to the other depicted fighters of WWII (as of version 4.11.1; time will tell if 4.12 is any better). Of the later fighters, only the Hellcat needed 'much' trim adjustment, but it was considered easily done. That is obviously not my experience in this simulation. The Merlin Mustang from every contemporary account and description needed very little or no trim adjustment for minor changes in speed or throttle (the Allison Mustangs needed practically none at any speed), but the in-game version needs trim adjustment in elevator and rudder for every variation of 10kph (that's only 6 mph, fellow Yanks) in speed or 5% of throttle, which is considerably more than either of the two best known study simulations of the P-51 depict (and strangely enough, I found a quote from a pilot in America's Hundred Thousand that complains of exactly that sort of behavior in the P-40,only for speed variations of as little as 10 mph (or 16 kph), which tells me that the trim model would be overdone by at least 60% even if it were assigned to the universally acknowledged worst trimming American fighter of the war). The real P-38 needed NO elevator (or rudder) trim for speed and throttle variations (per America’s Hundred Thousand), but the Il-2 Sturmovik Lightning will go literally straight up when you push the throttle forward without shoving the stick three quarters of the way forward at the same instant and punching the elevator trim button constantly for as long as the speed continues to increase. (and it's a lot slower than the real thing was) The real life P-47 needed no elevator trim for initial acceleration, but the in-game version does the same thing as the Lightning, with the added entertainment value of needing a ton of right rudder as well, and like the Corsair, the nose tends to dip as speed increases in the level plane; by this I mean that the angle of attack varies significantly with speed, something I've never read or heard about in these aircraft in over 45 years of reading, modeling or personally talking to men who flew these aircraft (you'd think that somebody would have mentioned it...). As for the Spitfire, I have no documentation or discussions of its trimming requirements at all, which would indicate to me that it was fairly well-behaved by the standards of the day (it was well-enough known as an easy aircraft to fly that even German pilots would say "Anyone can fly a Spitfire," which implies to me that they considered themselves more manly because they had tamed the 109...). Yet the Il-2 Sturmovik Spitfires demand a lot of trim adjustment, about the same degree as the Mustang, although with the added difficulty of that hard to read Turn and Bank needle arrangement. In short, in this simulation these specific aircraft are much harder to trim and control than the real ones were, particularly when measured against the other WWII fighters depicted in this sim, and all of them demand un-historic trim adjustment in the form of multiple button presses for relatively minor variations in speed and throttle settings, as well as climb or diving conditions, and it is next to impossible to roll your trim settings to a set position in anticipation of a sudden change in speed or throttle, as the real-life pilots did regularly. Exaggerated behaviors like the ones we experience in this sim would have made these fighters practically unacceptable as combat aircraft, and make "historical tactics" next to impossible. No amount of brains in the world is going to change that. cheers horseback
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#19
06-24-2013, 06:39 PM
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I like the suggestion about neutralizing trim once maneuvering begins, but I believe that the trim models for these aircraft need to be put in line with the other 'stock' aircraft in the game, or that we get a short-term HUD display indicating your trim displacement every time you make an adjustment (like when you change radiator, PP or throttle), so that you know just where the hell you are in terms of trim state--as I pointed out in earlier posts, a RL pilot would roll in more trim to a pre-set point in anticipation of a dive or increased throttle. I've also been toying with making a trim box with a 20:1 gearbox on each pot so that I can make the teeny-tiny adjustments to my pots that the game demands (and how is it that one button press of 1/80th of total deflection is so necessary?) and at the same time make the larger changes for something I'm about to do. cheers horseback
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#20
06-24-2013, 08:07 PM
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Interesting to see what TD did to some of the FWs... No wonder you can easily get caught with your pants done
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Linear Mode
