TurboHog Posted August 2, 2014 Share Posted August 2, 2014 There seems to be something wrong with it. Try flying 250kts IAS at 40000ft in neutral (default) weather conditions. It behaves much like when you are flying too fast at low altitude (unintentional rolls). Try pulling a 2g turn and you will tumble out of the sky. I suppose that's not what it should do? Or is it really that uncomfortable to fly at high altitudes? 'Frett' Link to comment Share on other sites More sharing options...
jocko417 Posted August 2, 2014 Share Posted August 2, 2014 What's the machmeter say at 250KIAS at 40,000'? Link to comment Share on other sites More sharing options...
effte Posted August 2, 2014 Share Posted August 2, 2014 250 KCAS should equal M.82. ----- Introduction to UTM/MGRS - Trying to get your head around what trim is, how it works and how to use it? - DCS helos vs the real world. Link to comment Share on other sites More sharing options...
IvanK Posted August 2, 2014 Share Posted August 2, 2014 I guess its debatable that 2G could be sustained at .82/40K .... certainly no where near transonic buffet boundary's. Link to comment Share on other sites More sharing options...
jocko417 Posted August 2, 2014 Share Posted August 2, 2014 250 KCAS should equal M.82. Had your whiz wheel handy? :) Link to comment Share on other sites More sharing options...
effte Posted August 3, 2014 Share Posted August 3, 2014 Had your whiz wheel handy? :) Always. Never leave home without a CR-3! ;) ----- Introduction to UTM/MGRS - Trying to get your head around what trim is, how it works and how to use it? - DCS helos vs the real world. Link to comment Share on other sites More sharing options...
RagnarDa Posted August 3, 2014 Share Posted August 3, 2014 (edited) Behaviour at high altitude? I guess its debatable that 2G could be sustained at .82/40K .... certainly no where near transonic buffet boundary's. What is the critical mach of the Sabre? Edited August 3, 2014 by RagnarDa typo DCS AJS37 HACKERMAN There will always be bugs. If everything is a priority nothing is. Link to comment Share on other sites More sharing options...
TurboHog Posted August 3, 2014 Author Share Posted August 3, 2014 Aren't the adverse high speed aerodynamic effects based on (absolute) airspeed. Suppose I try to prevent these effects from happening I must be flying 200kts indicated at 40000ft. You can not even a do very simple manoeuvre. Surely that can't be right? 'Frett' Link to comment Share on other sites More sharing options...
RagnarDa Posted August 3, 2014 Share Posted August 3, 2014 (edited) Behaviour at high altitude? IAS is the relative dynamic pressure, not the airspeed. The best measure of airspeed at height is your Mach meter which uses calculated TAS. The adverse effects are because of the high airspeed around the airplane body. Hope that helps. Edit: Think of it like this: You need IAS to not stall, but it will decrease as you climb. On the other hand you shouldn't fly too fast because of sound barrier effects. Look up http://en.m.wikipedia.org/wiki/Coffin_corner_(aerodynamics) Edited August 3, 2014 by RagnarDa more explanation DCS AJS37 HACKERMAN There will always be bugs. If everything is a priority nothing is. Link to comment Share on other sites More sharing options...
TurboHog Posted August 3, 2014 Author Share Posted August 3, 2014 IAS is the relative dynamic pressure, not the airspeed. The best measure of airspeed at height is your Mach meter which uses calculated TAS. The adverse effects are because of the high airspeed around the airplane body. Hope that helps. And how does stall speed change in IAS? It remains the same or becomes lower? 'Frett' Link to comment Share on other sites More sharing options...
RagnarDa Posted August 3, 2014 Share Posted August 3, 2014 The stall speed remains the same but the IAS-readout will decrease as the air get thinner. Again, IAS is dynamic pressure which is what you need for the wings to generate lift. Flying at or above the critical Mach could cause stall-like behaviors like Mach-tuck but it's not the same thing. As you get higher you will have a progressively smaller window between too fast (Mach-effects) and too slow (stall). Apparently the U2 had a window of 5kts when at its operating height... DCS AJS37 HACKERMAN There will always be bugs. If everything is a priority nothing is. Link to comment Share on other sites More sharing options...
RagnarDa Posted August 3, 2014 Share Posted August 3, 2014 Dynamic pressure is the force acting on the airplane. DCS AJS37 HACKERMAN There will always be bugs. If everything is a priority nothing is. Link to comment Share on other sites More sharing options...
Knubinator Posted August 3, 2014 Share Posted August 3, 2014 What is the critical mach of the Sabre? Mach .92 I believe, since that's at the point that the wings so providing lift and you begin to lose control. i7 4790k @ 4.4, 32GB RAM, RX480 GTR I fly it all. Link to comment Share on other sites More sharing options...
krazybiskit Posted August 4, 2014 Share Posted August 4, 2014 I thought there was a post about how sabre had a compressability issue between mach .8 and mach .9 Link to comment Share on other sites More sharing options...
26-J39 Posted August 5, 2014 Share Posted August 5, 2014 There seems to be something wrong with it. Try flying 250kts IAS at 40000ft in neutral (default) weather conditions. It behaves much like when you are flying too fast at low altitude (unintentional rolls). Try pulling a 2g turn and you will tumble out of the sky. I suppose that's not what it should do? Or is it really that uncomfortable to fly at high altitudes? I have no problems holding a 210-220kt sustained 2.5g turn at 40,000. I was actually suprised how well she held energy. Major buffeting if I hunt for 3g. Link to comment Share on other sites More sharing options...
Sabredog Posted August 6, 2014 Share Posted August 6, 2014 The Sabre seems pretty response to me at altitude. Quite pleased with how she handles. With less air to bite into up there it's difficult to put on the G's without the wing exceeding the critical angle of attack. Link to comment Share on other sites More sharing options...
whartsell Posted August 6, 2014 Share Posted August 6, 2014 the second half of this video explains it well.... yes I know its the FJ2 (Navy F-86) but the flying qualities are similar Arduino,EOS and Helios Tutorial Static ATC menu mod Link to comment Share on other sites More sharing options...
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