Question

Given a Density Ratio of 0.5328, what is the approximate Density Altitude?

Answer 1

we haveat 0 ft we have sigma =1   at 20000 ft we have sigma = 0.5328at

Density Ratio of 0.5328 so....

15000 ft we have sigma = 0.6292for every ft higher than 15000 ft we have (0.6292−0.5328)/5000=1.928∗10−5(0.6292−0.5328)/5000=1.928∗10−5variation of σσtotal variation of σσ is 0.6292−0.5589=7.03∗10−20.6292−0.5589=7.03∗10−2which means a variation in altitude of 7.03∗10−2/1.928∗10−5=3646.37.03∗10−2/1.928∗10−5=3646.3 ft above 1500015000 ftthe density altitude is 15000+3646.3=18646.315000+3646.3=18646.3 ft