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  1. #1

    All planes 30 mph slower???

    Does anyone know why all of the planes are 30+ mph slower than they r supposed to be. Has anyone else noticed this? I'm running a clean install, no mods, and current patches. Even at 10% fuel and cowl flaps closed they r still slower than they r supposed to be. Warbirds, Aces High, and even old fighter ace got it right. I thought il2 was supposed to be better than them.

    It makes a big difference. Turn fighter r 30 mph closer to stall speed and zoom n boom fighter r starting every fight with less energy. The f4U-1D struggles to just get to 300 mph, it's supposed to do 400 mph in cruise, what gives???
    Last edited by shop692237986; 07-05-2012 at 03:17 AM.
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  2. #2
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    Quote Originally Posted by shop692237986 View Post
    Does anyone know why all of the planes are 30+ mph slower than they r supposed to be. Has anyone else noticed this? I'm running a clean install, no mods, and current patches. Even at 10% fuel and cowl flaps closed they r still slower than they r supposed to be. Warbirds, Aces High, and even old fighter ace got it right. I thought il2 was supposed to be better than them.

    It makes a big difference. Turn fighter r 30 mph closer to stall speed and zoom n boom fighter r starting every fight with less energy. The fuf4 struggles to just get to 300 mph, it's supposed to do 400 mph in cruise, what gives???
    Are you taking into account the difference between True airspeed and Indicated airspeed? It throws a lot of people off.
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  3. #3
    Senior Member thefruitbat's Avatar
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    Quote Originally Posted by berg417448 View Post
    Are you taking into account the difference between True airspeed and Indicated airspeed? It throws a lot of people off.
    including the OP.
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  4. #4
    Global Moderator Tully__'s Avatar
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    All instruments and readouts in the game show indicated air speed except the arcadish ASI that shows in no cockpit view. The speedbar (red numbers in the bottom left corner of the screen) show indicated air speed and are rounded down to the nearest 10 of whichever unit you currently have it displaying. Except at or very close to sea level, indicated air speed is significantly lower than true air speed. Performance specifications are quoted in true air speed and adjusted for standard temperature and air density figures. They are also quoted for a specific load configuration, adding ammunition or other weight that was not carried in the test will reduce the achievable speed.

    As most (all?) aircraft can only achieve their top speed at some significant altitude above sea level, you'll never see the quoted top speed figures except for if you're flying with cockpits turned off. Even then, the only map in the game that's at standard temp and density is the Crimea map at noon, all others vary in at least temperature. If you're going to test for correct top speed you need to fly at the aircraft's rated top speed altitude in test configuration (correct fuel and stores load for test conditions) on the Crimea map and turn off the cockpit.

    To further add to the difficulty of achieving rated top speeds, any control input or uncoordinated controls creates drag. If you're not flying absolutely smoothly with the rudder perfectly coordinated and trimmed as close as possible to "hands off" level flight, you'll probably be incurring a 15 - 20mph drag penalty.

    Edit:
    Quote Originally Posted by shop692237986 View Post
    The fuf4 struggles to just get to 300 mph, it's supposed to do 400 mph in cruise, what gives???
    Assuming "fuf4" refers to the F4U-D1, I ran a test and achieved 620km/h (approx 385mph) @ 3600m (approx 11,800ft) without being particularly strict about test conditions. As a quick look 'round the internet failed to find specs for this machine that quoted the altitude at which it achieves max speed, I suspect it could do better at higher altitudes.
    Last edited by Tully__; 07-05-2012 at 01:03 AM.
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  5. #5
    It will also be helpful to mention under what conditions you are doing your testing, i.e, which aircraft, map, altitude, loadout, engine setting, etc. As Tully_ says, depending on your altitude, your indicated airspeed will be a lot slower than your aircraft's actual speed.
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  6. #6
    That was a great explanation! I did not factor in the temp when converting IAS to TAS. I suppose since most of the maps are based in the pacific it would significantly affect performance. I also wasn't aware that the no cockpit view displayed TAS. That will be a useful tool for doing a performance test.

    I pulled some numbers off of ND's Aircraft giude and they have the f4u-1a/d at 575 km at sea lvl and 678 km at 7000m. Your test run was pretty close. Great job! Did u read that speed off the no cockpit view? What was the IAS?

    I also found a post on the 1C forum about the f4u-1d. They said in the last update they significantly reduced the perf of the allied pacific fighters. The corsair seemed to take the biggest hit in terms of acceleration and max speed.

    Does anyone have a guess as to what they use for OAT's on most maps? That would help to explain why we are seeing lower than expected IAS. At sea lvl with a std temps IAS and TAS should be equal. This is where we are seeing the 30 mph diff.
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  7. #7
    Global Moderator Tully__'s Avatar
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    My test figures were TAS off the no cockpit display, I wasn't paying attention to the IAS but it was somewhere in the 400 - 500 range IIRC. The Pacific maps will all have temps higher than standardised, giving lower IAS than expected if I remember the science correctly. And yes, the higher temps / lower densities also affect performance. On some of the Russian winter maps, IAS actually reads higher than TAS at ground/sea level and heating issues are significantly reduced making it far easier to reach high speeds.
    Last edited by Tully__; 07-05-2012 at 06:06 AM.
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  8. #8
    I believe the Crimea map is the one closest to standard atmospheric conditions for testing, i.e. 15C but I don't know about the altimeter settings used by the map designers. This also seems to be the map most players use when posting performance figures.

    The acceleration of the Corsair did seem a lot slower after the initial 4.11 patch but I believe this was adjusted a bit in the 4.11.1 update. That said, compared to 4.10, it feels slower at low altitude, bleeds more energy in a turn, and it wasn't a great turning kite to begin with, and overheats a lot faster. All this means is that I have to learn how to fly it differently than before. It's always something with the Corsair, a few years ago there was much angst over the wobblies it had when firing the guns.

    Good hunting.
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