|
|
#131
05-31-2013, 07:32 PM
|
|||
|
|||
Quote:
The only trim location that was ever marked in any way on the planes I've flown is "neutral" for landing and takeoff in normal conditions. Even then, it's more of a guideline and you should trim the aircraft based on feel. This is true for aircraft that use electrical trim with a button or a trim wheel. That's also just how it works with Il-2: You adjust the trim until it feels right (ie, you don't have to put force into the joystick) and if need be, you just hit the trim reset button to center the trim again automatically for takeoff and landing, and re-trim from there. It's quite simple, and it works very well. 
|
|
#132
06-01-2013, 06:42 PM
|
|||
|
|||
|
Quote:
Now, for many of the aircraft modeled in Il-2 '46, this is not a great problem; their FMs are derived from 70 year old test reports, a modern physics model applied to ideal airframes and powerplants coupled with the vivid imaginations of the programmers, so an aircraft described as being light on the controls and easily trimmed needs a consistent (and small) set of up, down, left or right clicks of trim to settle the ball and establish flight speed at almost every speed. Even aircraft known to be very demanding of trim inputs (like the P-40 and the P-39 for example) are given a relatively forgiving trim model. And we don't even address stuff like landing behavior, which would lead to conservatively, at least two thirds of the 109 and P-40 landings ending in disaster (among other aircraft--but these two would draw the most complaints). However, there is another class of aircraft that has a rather extensive modern set of data, which is measured by the modern standard: the late war US fighters, the Spitfire to some degree, and I suspect, the FW 190 series, now that 1:1 scale replicas are on hand and the findings from their flights are being widely published. In my ten plus years' experience with this game, in these aircraft, the trim adjustments do not result in a steadily decreasing pressure on my joystick's springs as I struggle to maintain level flight or even a relatively well trimmed state; instead, the aircraft will suddenly go up or down once the trim level exceeds the ideal (and I do not hold the button down--I tap it just as you and Luno have repeatedly described). While WWII era reports tell us that these aircraft were easy to trim and that their controls were generally light and well balanced (even more so than most of the reports of other WWII era fighters that are given, shall we say, more optimistic trim models), we know that by today's modern standards, they were more demanding than modern jets with boosted controls or the average modern civilian general aviation aircraft with less than a quarter the horsepower and even less proportional payload capacity, packed with every modern convenience and engineering miracle to make the pilot/purchaser's task easier. What a shock. To think that men who were picked from the cream of their nations' youth for their physical fitness and intelligence in an era when so much more work was done with human muscle power might find the same stick and rudder forces you or I might find objectionable to be 'light', or that more extensive trim inputs would be required from the peak of the aircraft engineering and design in 1942 compared to the modern commercial light aviation standards of the 21st century, or that of supersonic jets that don't have to deal with stuff like propellers and torque, much less p-factor. However, the trim behaviors of these aircraft are clearly more consistent with somewhat exaggerated modern reports rather than with the reports of the WWII tests and pilots' impressions and the instruments also appear to be judged by more modern standards, if the gross inaccuracies of the late-war Western fighter's instrument panels in the game are compared to the game's depictions of more accurate readings from earlier generation British & American instruments in the Hurricane, Spitfire Mk V, the P-39 and P-40 series fighters. And then the game's advocates claim that they are merely catering to the demand for 'accuracy'. In-game, this clearly saps a lot of the power and performance of this group of late war aircraft the moment they enter into common combat maneuvers, because even minor imperfections in trim result in extra drag penalties (which to me seem somewhat excessive and would go a long way towards explaining why the Mustang has so much better acceleration than the P-38 and the paddleblade-equipped P-47D-27, when the historical record says that all three were fairly close and that the P-38 had the best level acceleration of the group). Add in the rather odd behaviors in trim response that I found at certain speed ranges (and at the first application of full power with the so-called heavies) and it becomes very difficult to reconcile the in-game behaviors of these fighters to wartime reports. It simply becomes very difficult to trim to rapidly changing conditions because the penalties seem to me to be both out of proportion and hard to make sense of and anticipate. Rather than completely redoing these aircraft's FMs, I think the quick fix is to at least let the pilot of the high-trim fighters be able to see their current trim state as it changes, and possibly to re-work some of the instruments' depictions to a common standard of readability and accuracy in Wide view. cheers horseback PS: Yes, I know that I'm asking someone else to do extra uncompensated work 
|
|
#133
06-01-2013, 06:46 PM
|
|||
|
|||
|
Quote:
Had the pilot of the 109 he was fighting survived the fight, his memoir might have included stuff about how slow the stabilizer trim wheel responded, or how heavy the rudder got as he compensated for the higher or lower speeds as he climbed and dived, how the supercharger became steadily less effective the higher he went, the way the windshield kept frosting up or how sloppy the stick got at 10km (and all of these things can be read about in any number of well known resources like Caldwell's JG 26: Top Guns of the Luftwaffe), and then his thirty something civilian co-author would still ask him to 'punch it up' for the reading audience of the late 1980s. I've read a number of pilot memoirs that state quite flatly that the Mustang didn't need a lot of trimming in combat because the stick forces were exceptionally light and well balanced by the standards of the time; Anderson's comment simply shocked me when I read it for the first time because it contradicts almost everything else I had read on the subject. You trimmed for level flight on long distance escorts, sudden changes in power and for the depletion of fuel in the wing tanks (otherwise, there would have been no need for aileron trim), and you would add a little nose up trim for landings; everything else was reported as a matter of pilot preference. I long ago transcribed the trimming sections of America's Hundred Thousand for the old UbiSoft Il-2 forums; I'll be happy to post them here, along with 354th FG ace Richard Turner's description of the flying qualities of the Mustang, or David McCampbell's description of the Hellcat, if you need more proof. cheers horseback Last edited by horseback; 06-01-2013 at 06:48 PM. Reason: rephrasing for clarity
|
|
#134
06-01-2013, 08:12 PM
|
|||
|
|||
|
These are my first efforts: I find that just attaching the pictures works better than trying to attach the whole Excel Workbook and allows greater access for everyone. The longer and flatter the curve, the better the acceleration over time. Notice how much faster and better accelerating the early P-40E is than the later P-40M.
cheers horseback Last edited by horseback; 06-01-2013 at 08:14 PM.
|
|
#135
06-01-2013, 08:20 PM
|
|||
|
|||
|
More Charts: RAF vs LW, Spit IX vs Mustang and Japan. Again, the lower and flatter, the better the acceleration. Look for the anomalies in the curves; these may be indicators of the odd behaviors I noted earlier or inconsistencies in the FM.
Enjoy/debate. cheers horseback
|
|
#136
06-02-2013, 12:39 PM
|
|||
|
|||
|
Quote:
Quote:
The 270-350 and the 350/370 interval is the same spacing as the other ones that are only ten kph apart in the graph, may be misleading. And to be nitpicking: These are not a(cceleration) graphs, these are v vs. t diagrams.
|
|
#137
06-02-2013, 06:11 PM
|
|||
|
|||
|
Quote:
Please note that all of these aircraft were considered very well behaved and easily trimmed for high performance fighters of the day; the Mustang was not merely a speed and range fighter, the Corsair was considered 'touchy' mainly in the carrier landing regime (and because it was invariably compared to the much more benign Grumman 'cats in that respect), and the Hellcat was, like Mary Poppins, practically perfect in every way for a carrier fighter in the Pacific (it just wasn't <quite> as fast as the Corsair). All of them were considered to be easily transitioned into (the Mustang particularly--the 8th AF transitioned all but one of its P-47 and P-38 equipped groups into it in the middle of high combat operations during early to late 1944); easily taught and mastered. By contrast, the Il-2 '46 P-39 needs somewhatmore trim than most aircraft of its era, but it is consistent and therefore much more easily anticipated. The real thing had a reputation for being touchy and for the CG changing critically when the cannon ammo was expended; it was NOT consistent and as easily anticipated as it is depicted in this game. And what's with the instruments being so much more readable and accurate on earlier generation fighters? Now, about the P-40 comparisons. The E model is (as its reputation suggested) neck and neck with the P-39 in the early acceleration phase from 270 to 370 kph both of them taking 23 seconds to add 100 kph of indicated speed, and then the Warhawk gradually dropping back; by contrast, the M model Warhawk is 7 seconds behind the E, then 10 seconds at 380, 11 seconds at 390, 13 seconds at 400, 20 seconds behind at 410, 33 seconds at 420, and then it poops out at 430, 31 seconds behind the E model, which at that point is midway between 440 and 450 kph. At a constant speed of 370 kph, a 7 second lead is well over 700m, which we can safely assume to be out of range. It becomes much greater if you are accelerating away, and the E is right at 400 the same time that the M is wheezing and puffing up to 380. My impression was that the later P-40 models got more powerful engines to match the extra weight of armor, new radios and so on, and that high alt performance improved marginally in the Allison powered models. My (limited) sources on the P-40 say that the M model was a full minute faster to 15,000 ft than the E models, which should result in obtaining level speed more quickly if all other things remain the same (and they mostly do). Those same sources state flatly that performance at lower altitudes remained largely the same, which isn't what is reflected here. US Naval aviators were an eyelash away from mutiny when the slower, heavier, shorter ranged and lesser firing time F4F-4 Wildcat was introduced just before the battle of Midway. Army Air Force officers would have raised hell if they were handed a pig like the P-40M depicted here, and their objections would be a part of the historical record, but I find no such reports. I'm inclined to call the M model in Il-2 '46 bogus at best. cheers horseback
|
|
#138
06-02-2013, 06:16 PM
|
|||
|
|||
|
Oops, forgot the Soviet Fighters' Chart. Non nitpickers will appreciate that it compares the ability of these four fighters to increase their speeds at this height and at these speed ranges. Everybody else will have to whip out their scientific calculators and see whose is bigger.
cheers horseback Last edited by horseback; 06-02-2013 at 06:21 PM. Reason: got the number of aircraft wrong; math challenged
|
|
#139
06-02-2013, 06:50 PM
|
|||
|
|||
|
Quote:
Quote:
|
|
#140
06-02-2013, 08:09 PM
|
|||
|
|||
|
Gens, this discussion is getting out of control. Simply too many aspects of this great game are blurred together. What if this thread were continued as separate threads?
- late-war high-performance aircraft issue (if any); - relation of FM and flight controls discussion (trim, charts, etc); - cockpit/hud display of control settings issue (what must/should/could we have, and what we don't need); - general reality issue ('realistic' cockpit visibility as a handicap). Just a suggestion. 
|
 |
|
|
Linear Mode
