FishBike

Yup, I hit about M2.15 today at just about 37,000 feet, clean.

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.

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?

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. :(

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.

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.

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?

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.

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?

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.

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.

Heh, yes, the MiG-21bis has nose wheel steering the same way a shopping cart does. ;)

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

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.

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.

Q: "Did the Huey suffer from vortex ring state?" A: "No, it died very quickly."

At the top right corner of the RSBN control panel, there are two switches. In the manual they're numbered LV21 (RSBN azimuth correction) and LV22 (RSBN distance correction). I have been turning these on when using the RSBN and it seems to work fine. Others I know leave them off, and a tutorial video I saw today also left them off. I can't find any further information about these in the manual, or anywhere else for that matter. What do they do?

I had the same problem in a mission today. The "lock" tone continued after all enemy aircraft had been shot down, and all friendly aircraft had turned off radars. The only radar that was operating was on the ground, which doesn't normally seem to trigger the RWR at all.

I had the same thing happen to me yesterday, in a mission flown at 7,000-7,500m for quite a long time. The gauge read 50 for me as well. When going through the startup for that mission, I accidentally clicked on the wrong lever to lock the canopy and ended up locking it and sealing it in one click. I don't know if that resulted in an unpressurized cockpit (the cabin altimeter read 3,000m like it normally does) but perhaps that is a factor.

I mapped the TDC range axes to one of the rotary controls on my X-52 Pro. Works perfectly.

Here's what it says in the flight manual: "Angle-of-attack indicator YYA-1 shows the current angle of attack to the pilot. The scale of the YYA-1 indicator is calibrated in degrees of local angle of attack (corresponding to the deflection angles of the vane of transmitter UYA-3) with a scale increment of 1 degree; the scale is numbered every 10 degrees." The key words there are "local angle of attack", e.g. the angle of the AoA vane, uncorrected for effects of local airflow around the vane. So it is calibrated in degrees but does not read the actual angle of attack.

The real-world flight manual for the MiG-21bis says this gauge indicates the "local angle of attack" in degrees, e.g. the degrees of deflection of the AoA measuring vane. It also says that stall = 33 degrees.

You may want to check your axis mappings. After doing the upgrade, I found two more axes had been mapped to the brake lever, so it was on all the time pretty much. The takeoff performance is somewhat reduced with the brakes on. ;)

I think this might be improved in the latest patch. Before updating, I did a flight where I climbed to 10km and then stayed at or slightly above that altitude until the oxygen pressure gauge read 40. That took 23 minutes from the start of the takeoff roll. After the patch, I did the same thing, and it took 40 minutes. So allowing for a few minutes at the start of the mission where no oxygen is used, it seems like it lasts about twice as long now in that test. Either that or I messed up the test somehow. Anyone else have any results to share?

I'm not sure what I am missing, but for some reason I'm unable to get the Sabre's cockpit to pressurize properly. I verified I have the canopy closed, the "press/ram" switch in the "press" position (on the left console), and the pressure switch at 2.75 psi (though it's the same at 5 psi). What I see is that cockpit altitude = actual altitude, oxygen gets used up quicker than expected, and toggling the pressure switch between 2.75 and 5 psi doesn't seem to do anything. I must be missing a step somewhere.