Guest blocked pitot Posted May 1, 2003 Share Posted May 1, 2003 Can someone tell me how to figure out the SOS (with the CR 2 computer)for a specific pressure altitutde and temperature? Link to comment Share on other sites More sharing options...
Moon The Loon Posted May 2, 2003 Share Posted May 2, 2003 http://williams.best.vwh.net/avform.htm#Mach Sorry, but thought it easier to just post the link. You can dig through the material to find what you need! Link to comment Share on other sites More sharing options...
Guest Snowshoes Posted May 2, 2003 Share Posted May 2, 2003 The speed of sound varies with temperature only. I have simplified the Rankin and air constants so all you have to do is plug in the temperature in the following: c = 38.97 * square root(OAT+273) where c is the speed of sound in knots (nautical mph) and OAT is the outside or ambiant STATIC air temperature in °C (ie do not use the TOTAL or RAM air temperature.) To determine your Mach number(M), simply perform the following calculation: M = TAS / c Cheers Link to comment Share on other sites More sharing options...
Guest blocked pitot Posted May 2, 2003 Share Posted May 2, 2003 Thanks guys. Link to comment Share on other sites More sharing options...
IFG Posted May 2, 2003 Share Posted May 2, 2003 Hi, bp. - The others gave you valid formulaic methods, but if you're still wondering how to do it with the CR2, here's a recollection from the Dark Ages: One of the inner windows is used to make that calculation, where the circular scales for Indicated temp, TAS, and Mach # are adjacent to each other. It's a bit confusing without a diagram, but if you place that radial lubber line thingy over your TAS (not IAS), and align the intersection, of the curved OAT line(not TAT) with the rising arc underneath it, so that it's under the "lubber" line, the arrow will indicate mach #. Hopefully, this will seem more clear if you're holding a CR2 in front of you. :S Cheers, IFG Link to comment Share on other sites More sharing options...
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