HWasp

I hope it is the Su-22. It has not been denied like the Mig-23 and maybe the image of the airfield is taken by one of the sensors of the KKR recon. container. It is a 1970s aircraft as well.... Due to the other modules expected "soon" I don't think releasing anything less with this much teasing is a good idea.

True, but the whole reason I have done the glide test and reported the findings is because the Mirage just did not want to slow down in level flight with and without the engine running, suggesting to me that some drag values in that speed region are wrong. I am quite certain, that an engine failure at 1000ft AGL / 300kts would be a cause for immidiate ejection for most single engine fighters irl. Normally I'm not the guy who is always comparing charts to DCS aircraft to find problems. If it feels ok, then I just fly it happily. I think that many aircraft in this sim have an extremely realistic flight model, certainly the best simulation currently available. I'm very happy, that RAZBAM has taken note of the problem. :)

Hi! Thanks for the replies! Wing loading and glide ratio are not that closely connected. There are plenty of general aviation aircraft for example that have a low wing loading but have a glide ratio below 6. (PZL Wilga, Zlin-142). Also a Cessna 152 has it somewhere around 10 if I remember correctly. The good old high wing loading 737 glides much better than those and does have a max. glide ratio around 14-16 (737-400, no winglets, no nothing). One of the more difficult things flying any airliner is to get it to descend. They are quite the gliders with clean wings. Now the reason why the mirage cannot have the same glide performance as the 737 is the shape of the wing. A delta wing (and other low aspect ratio wings) generate most of their drag due to the vortices forming around them (except very low AoA , well below 5). Just google induced drag, vortex drag and delta wing aerodynamics. This is also the cause, why delta fighters bleed energy in turns like crazy. Slats fitted to aircraft are present to reenergise the boundary layer on the upper surface of the wing in order to delay flow separation to higher angle of attack. It basically increases stall AoA, at the cost of additional drag, lowering the glide performance. I have also done a test without engine power, if you read my whole post. That shows that high idle thrust is not the cause. As for the speculation part: I think I have provided you the document that I have used as source for the calculations, and also some of the numbers. I also noted that these calculations are not accurate, they are there only to show you that something is way, way off. Calling this a speculation is not exactly polite.

SOLVED! Hi! I have flown simple test flights with the new Mirage FM, that consisted of idle thrust descents from 10000 ft at different speeds. Results: At 300 kias glide ratio was 13,2 (AoA 5) At 250 kias glide ratio was 14,9 (AoA 7) At 200 kias glide ratio was 10,7 (AoA 10) All descents on idle thrust holding steady indicated speeds. Using the equation for total drag for delta wing in the attached pdf with an Aspect Ratio of 3,02 the total drag coefficient: Cd = 0,0373 at AoA 5 (300 kias) Cd = 0,0739 at AoA 7 (250 kias) With these values and a weight of 10300kg (clean ac 80% fuel) and a wing area of 41m2 i have calculated the following Lift to Drag values L/D at AoA 5 (300 kias) = 5,44 L/D at AoA 7 (250 kias) = 3,95 I don't expect my calculations to be accurate, but the difference here seems excessive to me (13,2 to 5,44 and 14,9 to 3,95) The graph in the pdf shows roughly similiar Cd values for a generic delta wing design. I have also flown the same test with the Belsimtek F-5 and the ED Su-27 for reference and have found the following glide ratios: F-5: at 300 kias 6,32 at 250 kias 7,91 Su-27: at 300 kias 6,42 at 250 kias 7,13 I am aware that these are different airframes but the layout of the mirage does not justify such a great difference (13 to 6 and 15 to 8 ) I also did a short test to check if high idle thrust was the problem: I turned the engine off at 1000 ft AGL 300 kias and measured the time to decelerate to 250 kias. This took 33 seconds which I find quite hard to believe. I restarted the engine with some delay and was able to stay in the air after more than 1 minute without engine thrust. I fly the Boeing 737 for a living, which is no Mirage but still is a high performance jet with high wing loading. For me this aspect of the FM seems unrealistic. The new Harrier doesn't have this problem (maybe because the constant flaps 5). I am afraid that some drag values in this speed region are incorrect as this has been a problem with the old FM as well just not to this extent. I would love to see some charts from RAZBAM that show L/D and drag coefficients if available. I hope that my post will help to improve this great bird! (or make it a flying brick :)) Expaero04(1).pdf

Hi! I have tested the new FM for the M2000 and I think there is an issue here that is present since the beginning and now feels worse with the update. Drag below 400 kts and above approx. 200 kts feels extremely low. I have made very basic test flights with clean aircraft and around 80 percent fuel at approx. 10300kg. The test included idle power descents from 10000ft at steady speeds. Results: at 400 kts AOA 3 deg. glide ratio 7,8 (7,8nm horizontal distance for 1nm alt.) at 300 kts AOA 5 deg. glide ratio 13,2 at 250 kts AoA 7 deg. glide ratio 14,9 at 200 kts AoA 10 deg. glide ratio 10,7 I find that the glide ratios at 300 and 250 kts are way over the values that I would expect from a delta wing fighter with high wing loading. I have made some calculations with the equation for delta wing total drag (see attached pdf) where I used an aspect ratio of 3,02 (AR). The end result was a lift to drag ratio of: L/D= 5,44 at AoA 5deg at 300 kts Cd = 0,0373 L/D= 3,95 at AoA 7deg at 250 kts Cd = 0,0739 I don't expect this to be accurate calculation, but it shows the huge difference. (way over 10 vs below 6) There is another (low quality unfortunately) pdf that shows Cd values in the same range that I have calculated. I also did the same idle power descent test to the Belsimtek F-5 and the ED Su-27, and both resulted in glide ratios between 6 and 8 for the same speeds. I know that these are different aircrafts but not this different. (14 vs 7) Mirage has basically half the drag presently in the simulator. I also did a test flight where I turned the engine off at 1000 ft AGL at 300 kts to kill the idle thrust, and it took about 30 seconds to decelerate to 250 kts. I restarted the engine with quite a delay after this (around 220 maybe) and I was still able to survive this with an altitude loss of around 500 feet close to stall speed. The time spent without thrust was way over 1 minute. This seems quite wrong to me. Don't get me wrong, I still like both the Mirage and the Harrier, but I think this problem should be adressed. NACATN1468.pdf Equations total drag.pdf