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FishBike

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Everything posted by FishBike

  1. Yup, I hit about M2.15 today at just about 37,000 feet, clean.
  2. As luck would have it, I just finished running through the cold start process again trying to learn it. A momentary push on the T/O trim button is all it takes.
  3. What I'm saying is the yaw moment DOES go to zero when the rudder is centered. And because you have a 1-2 degree per second yaw rate, that rate will continue until a yaw moment in the opposite direction makes it stop. In the air that yaw moment happens due to sideslip, but on the ground there is hardly any sideslip. The main gear would contribute some yaw moment to reduce yaw rate, but they are very close to the center of gravity, so may not do that much.
  4. That sounds kind of right to me, actually. The plane should have a moment of inertia in the yaw axis, so once you get any kind of yaw rate happening, it should want to keep on happening until some moment in the opposite direction stops it. In the air, if you get some yaw going with the rudder and then release it, you have quite a bit of sideslip, which results in an aerodynamic force on the vertical stabilizer that tends to point the nose back into the relative wind. On the ground, with the main gear on the runway, you don't get nearly as much sideslip happening and so there's not much of a side load on the vertical stabilizer when you let off the rudder again. So unless the flight control system deliberately puts in some opposite rudder momentarily to stop the yaw rate, I think it would continue for a little bit after you center the rudder.
  5. In the original 1.5.3 update 3 I couldn't even stay in formation with the tanker. After yesterday's update it is MUCH better and I think only the constant but slow pitching up was really throwing me off. It does seem you can counteract that somewhat with some pitch trim. How are other folks finding it after yesterday's update?
  6. Just re-tested this after today's update, and it looks great now. Yay! :)
  7. I just re-tested with today's update. Pitch control in general is much better now, the flightpath stays pretty much where you put it once you release the controls rather than taking 3-4 seconds to settle down like it did in the previous update. However the slow pitch up problem seems to be there still, especially in a gentle turn. :(
  8. Real planes often have a switch in the main landing gear that detects when the plane's weight is on its wheels. It's used as a signal to a bunch of systems to indicate "are we on the ground, or are we in the air?" I have no idea if RAZBAM has implemented it that way in the flight model, but it seemed the easiest way to describe what the bug looks like. Sorry for any confusion!
  9. RAZBAM continues to be awesome in responding to these kinds of things. :)
  10. Just noticed in the latest update that the switch detecting when the gear is on the ground seems to be hooked up to the nose gear instead of the main gear. One result is the inverted T symbol on the HUD, that is supposed to tell you how far it's safe to pitch up during takeoff and landing, disappears as soon as the nose wheel is off the ground during takeoff, and doesn't reappear until the nosewheel is back on the ground at landing. Making this feature not too useful. :)
  11. I did some slightly more formal testing this morning. The good news it is seems really easy to reproduce this behavior: DCS Version: 1.5.3.51870 Controls: checked that only one controller was bound to the pitch axis. Set a large deadzone (10) to ensure there was no pitch control input when the stick is centered. 1. Create a new mission file. Leave weather set at defaults (20 deg. C, QNH 760, wind 0 m/s). 2. Place M-2000C at Batumi, with waypoint type "takeoff from runway". Loadout: "empty", 100% internal fuel, 112 chaff, 16 flare, 100% gun (all defaults). Total weight=24,046 lbs. (Yesterday I was flying with a single external fuel tank and saw the same thing, though). 3. Save mission file and then run it from the "mission" menu. 4. Take off in full afterburner, raise gear, establish climb attitude, and then release the stick. 5. After a few seconds, the plane begins to slowly pitch up. (Ignore the TVV/FPM, look at the pitch ladder bars on the HUD). Leaving the throttle in full afterburner, the pitch up continues as the plane accelerates through 500 knots, and does not stop as it loses speed in the climb. I got to 53,000 feet and 160 knots and it was still happening. 6. Turn around and return to Batumi, descending at idle thrust and 350-400 knots. Same slow pitch-up continues. It seems to happen a bit faster in gentle turns (15-30 degrees bank angle) but pitches down in steeper turns (as expected). 7. Fly around Batumi at 5,000 feet maintaining 350 knots exactly. Same slow pitch-up behaviour continues. All of this was with the mode switch set to A/A, but I had it set to A/G yesterday and saw the same thing.
  12. Sure thing, I will do some more testing and see if I can give you some useful details about then this does and does not happen.
  13. Just wondering if anyone else has noticed that pitch attitude is not stable in the Mirage as of DCS 1.5.3 Update 3? The big problem where it would constantly pitch up, especially at lower speeds, seems to be fixed. But what I am seeing now is after getting it to fly level, it will slowly pitch up or down. I can use pitch trim to get it stable again for a little while, but it doesn't stay that way, and I didn't think we were supposed to need to trim the Mirage much anyway. It doesn't feel like the normal change in pitch trim with airspeed that we get in non-FBW aircraft either (e.g. it'll keep pitching up as speed decreases). It also seems like it takes a lot longer before vertical speed stabilizes after a small pitch attitude change, like 3-4 seconds. This was particularly noticeable during air-to-air refuelling. I know there have been a lot of improvements to the flight model lately, so maybe these effects are intended. Just wondering if anyone else has noticed them, and whether they are supposed to be happening?
  14. While doing some landing practice today, I noticed that at exactly 6.0 degrees angle of attack, the slats repeatedly deploy and retract. This was at around 250 knots in level flight, though it happened at progressively lower speeds as I used up fuel. To reproduce the issue, slow down until your alpha reads 5.9 and then continue a gradual speed reduction. As your alpha passes through 6.0, watch the leading edge of the wings and you'll see the slats shaking up and down. It stops before alpha reads 6.1. Speeding up through the problem airspeed also shows the issue. I'm pretty sure that's not supposed to happen!
  15. I noticed this happens if I've left the ignition/vent switch in one of the on positions. If I turned that off after shutdown, everything else goes off like it should.
  16. These things will happen with a module undergoing so much active development. It's a great module and you guys have been fantastically responsive on the various forums. No complaints here, just flying qualities reports from us amateur test pilots. ;)
  17. I'm seeing the same thing in the current alpha build. A turn at constant altitude with 45 degree bank results in about 1.0G (in the F2 external view) whereas it ought to be about 1.4G. Similarly, staying in formation with a tanker during a turn is very tough because the same bank angle and speed no longer results in the same turn rate/radius, and it should. Something definitely seems wonky in the latest build.
  18. We did some further testing of this issue today and determined a few things about it. The problem is reproducible, and the amount of time taken for blurred vision to set in varies with altitude. But not in the way you might expect. Below a certain altitude it does not happen (e.g. 5,000m). And also ABOVE a certain altitude it does not happen -- climbing up to 15,000m caused the effect go away! Somewhere between those altitudes, the problem happens quicker at LOWER altitude. When my friend and I were flying at 10,000m we both got the problem at exactly the same time. When I flew at 9,000m and he flew at 10,000m, I got the problem sooner by several minutes. We also tried turning on helmet vent, emergency oxygen, 100% oxygen, turning the cabin vent control on and off, and checked the pitot heat switches were on. None of this made any different, but climing or descending outside of the problem range of altitudes cleared it up quickly.
  19. A friend and I have been doing some missions where we're at higher altitudes for longer time (7.5 to 10 km for 30+ minutes) and have been seeing the blurry vision effect of hypoxia happening sometimes. We have been really careful to ensure the cockpit is pressurized and have also tried cycling the three switches on the left horizontal panel (helmet vent, emergency oxygen, and 100% oxygen) during startup as we had thought that was helping. But it happened again today despite that. We checked: - Cockpit sealed - Cabin altimeter shows 3,000m - Oxygen pressure near the top of the gauge and flow indicator blinking - Turning on 100% oxygen, emergency oxygen, and helmet vent did not clear the problem Descending to 4km solved the problem immediately. We were doing these flights for a long time in 1.2 without problems but seem to be encountering this in 1.5 beta. Is it a new bug? Something we are doing wrong in the startup that matters now? Has anyone else encountered this recently?
  20. I've been over 90,000 feet a bunch of times. The trick is to go up to 10-11km, accelerate up to over Mach 2.0, then do a 4-5G pull up to 60 degrees climb, and then just try to hold the nose up without stalling it. You WILL lose your engine but can continue climbing for a while after. You will then lose your generators too and will not have instruments for a while. But once you go over the top, you can push the nose down and get some speed back on the jet, then get the engine re-lit once you are back down at lower altitude and reasonable speed. It's survivable but exciting. I got to 95,481 feet this way yesterday, I suspect 100,000 might be possible with perfect technique.
  21. I haven't tried it after the most recent update, but before that it was possible to get to almost 80,000 feet (over 24 km) in a zoom climb. I think with enough practice to get the technique just right, it should be possible to do just a little better than that even. The best way I found so far is to accelerate to maximum speed at about 10km altitude, then do about a 4G pull up to 60 degrees nose up. Hold that attitude as long as you can and then just keep as much nose up as you can without stalling. The real trick is surviving the experience--I found if I stalled up there, I would fall out of the sky with the plane level but falling straight down, faster and faster until the G-forces make it explode. So if you try it, just make sure you don't stall (watch the AoA gauge and keep it out of the red zone). Don't pull up too much past 60 degrees or you may not be able to avoid a stall even with full forward stick at the top of the climb. I'm looking forward to trying this again in the next few days once I have some time and have installed the latest update.
  22. Heh, yes, the MiG-21bis has nose wheel steering the same way a shopping cart does. ;)
  23. Wouldn't it be the other way around, e.g. you would need a helicopter with LOW disc loading to have a downwash velocity low enough to get VRS at 300ft/min descent? There is some good stuff written here about VRS, written by a Sikorsky test pilot. It matches up well with what you posted re: disc loading and VRS and confirms it would be damn near impossible to get into in a V-22. http://yarchive.net/air/vortex_ring.html
  24. I'm not sure if this is a bug, but I'm noticing a sudden loss of engine thrust whenever I fly about 15,000m altitude. For example I will fly up to 10,000m and then begin acceleration up to Mach 2.0. I can climb at that speed until reaching 15,000m and then suddenly my airspeed will decrease as if I had pulled the throttle back to idle. Descending below 15,000m, everything goes back to normal.
  25. Interesting. In the english flight manual for the MiG-21bis, it says: "To reduce the takeoff run length, to shorten the time of aircraft acceleration after the landing gear is retracted, or to augment the rate of climb at altitudes below 4000m the second (emergency) power setting may be used." I am assuming if it reduces the takeoff run length, that means it must work while on the ground.
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