Expert: Mark Janus - 11/27/2007

Question
 Hello Mark,
My name is Calum, I am in 8th grade middle school and interested in a career in Aviation (As a pilot for the USCG), Anyways I am taking flight lessons as well, but my CFI and I can't figure out how to measure or even record density altitude because its almost the middle of winter.   

Thank you for your time!
Calum

Answer
This is a little outside of my area, but you can measure the barometric pressure, and the temperature, then you can determine the (dry air) density from the perfect gas law....  p=rho R T at different altitudes and relate that to the standard atmosphere

Hope this helps,
mj