Hello- Question about calculating Density Alt. On my Cessna 172, I refer to the POH when calculating Climb Rates. 1. If I am wishing to cruise at 4,500', do I want to calculate the DA at the airport and then calculate the DA at the Flight level...then take the difference between the two to get my rates? 2. When calculating the DA, on my E6B, it only asks for the pressure alt and the temp....do I want to adjust the PA for the Altimeter setting which is on the ground at that time, even though its 4,500 feet? Ex, if the alt setting is 30.2, I would subtract 257 from 4500 then proceed with the calculation? Any suggestions would be helpful.
(2)i assume you using this for take off and landing calculations. hear is how to find you DA with you PA and Air port elevation. First get the Metar and find the Alt setting. ie 30.19 then take the 29.92-30.19=-0.27 then take the -0.27*1000 (becasue 1"=1000') you then get -270ft than take your airport elevation say 5045-270=4775 your PA=4775 Now take you E6b and find the temp on the Metar and then plug the temp and PA into it. Match the PA and the Temp in the PA window then look in the DA window and you have your DA. (1) If you want to cruse at 4500 don.t worry about setting up the DA's since in your chart for cruse/climb you make corrections for non standard temperature. which will in effect count as the DA calculation's
