Windshear Warning with XML

[Guest Matthias Lieberecht]

Hi All,At the moment I'm working on a panel which has two windshear warning lights (amber and red). The warning system should be capable of detecting severe decreasing (and increasing) performance shears (i.e. increasing tailwind/decreasing headwind and/or downdraft) which could present an immediate danger to the aircraft. A detected increasing performance shear will result in an amber and a decreasing shear should result in a red warning light when enabled. I know how to scan the wind direction but I have absolutely no idea how I could realize such a windshear warning. Maybe someone here in the forum has an idea. I'm deeply grateful for every hint which is helpful to realize this gauge.Best RegardsMatthias

[phjvh 0]

Matthias,I use this one with more or less succes in my HUD:(P:Local Time, seconds) 0.2 % 10 * int 0 == if{ (A:Ambient wind velocity,knots) 0.5 * (>G:Var1) }(P:Local Time, seconds) 0.2 % 10 * int 1 == if{ (A:Ambient wind velocity, knots) 0.5 * s2 (G:Var1) - 0.1 / 10 * l2 + (>G:Var2) } It shows then:%((G:Var2) 10 >)%{if}%WINDSHEAR%{end}Of course with the appropiate sound of Doug!Hope it helps,Jan"Beatus Ille Procul Negotiis"

[Guest Matthias Lieberecht]

Hi Jan,Thank you very much for this tip. It's a very good base for my gauge. The only thing I have to do now is to find the difference for a caution (amber) and a warning situation (red). But this should be no problem and could be done on the same way. A warning condition will be when the tailwind increase, the headwind decrease or the wind angle increase and a caution when the tailwind decrease, the headwind increase or the wind angle decrease (all below 1500 ft. AGL).Best RegardsMatthias

[rcbarend 37]

Hi Jan, Matthias,After a lot of testing, I found I got the best results using:(A:AIRCRAFT WIND Z,knots)which gives you the actual windspeed in the aircraft's longitudinal direction. This make detection dependant not just of Ambient wind speed, but also on wind direction (the Z axis). Which is more appropriate (IMHO :-) ) to detect windshear, since the important thing here to detect the cause for a sudden increase/decrease of IAS.Now, this variable also varies with wind Turbulance, but if you set the detection threshold large enough (like 15 knots), it will only react to real, large changes in windspeed/direction.A good way to test it, is to set the "Gust To" setting in FS windsetting to a large value. Which gives instantaneous jumps in windspeed.You may find this interesting as well:http://forums.avsim.net/dcboard.php?az=sho...id=237622&page=Cheers, Rob

[Guest Matthias Lieberecht]

Hi Rob,Great news. Thank you very much.Yes, you're right. As also written in my last posting, especially for my gauge it's important to scan not only the windspeed but also the wind directon. I have to realize an amber caution (tailwind decrease, headwind increase or the wind angle decrease) and a red warning (tailwind increase, headwind decrease or wind angle increase). I use the original AlliedSignal MK VII mode 7 manual for it. I've also played a little bit with an up- or downdraft using a terrain closure scan, but the result was not good. Either the gauge reacts too soon (too sensible) or too late so I delete this thing for the time and just use the wind angle and speed for the windshear mode at the moment.Best RegardsMatthias