nathanmay Posted March 27, 2008 Report Share Posted March 27, 2008 i was showing a student how to calculate for DA and they brought to my attention that DA= PA + (100*(current temp.-ISA)). i was taught, and have been using 120 in my formula not 100. i looked further into it and have found numerous websites using 100 instead of 120. have i been wrong all this time? i was wondering if anyone could clear this up for me? Quote Link to comment Share on other sites More sharing options...
gmsemel Posted March 28, 2008 Report Share Posted March 28, 2008 I used DA= PA + 120 ( Temp C - ISA) since I was taught that in 1975 or so. I don't know were the 100 came from other than well its 100 and its a quick in you head thing. Close enough I guess. When we did it on E-6B's we would always get small differences in answers. I know the FAA writtens answers to these questions is based on the ASA electronic E-6B. If you round off round off on the High side and give yourself a little fudge factor on your performance charts. All it is is maybe throwing 75 to 100 lbs off the helicopter for a given set of conditions. Quote Link to comment Share on other sites More sharing options...
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