Student needs assistance density altitude calcs

One easy way is to find out the temp at the field you are at. Take the
standard sea level temp of 15C and using the altitude of where you are
at, subtract 2C for every thousand feet. For every 1 degree above
standard, add 120 feet, or 600 feet for every 5C. Add that to the
field altitude. Gives you a great ballpark idea in no time.

Example: 3,000 foot field at 20C
15C - (3 x 2) = 9C (should be standard temp for that altitude)
20C - 9C = 11
11 x 120 = 1320
3000 + 1320 = 4320 density altitude



On Tue, 15 Jun 2004 18:21:34 -0700, The OTHER Kevin in San Diego
skiddz *AT* adelphia *DOT* net wrote:

Anyone got a "formula" for figuring out pressure and density altitudes
quickly and reasonably accurately, specifically if the knowns are

Field Elevation
Barometric Pressure in inches of mercury
Temperature in degress Celsius.

My instructor went over this for quite a while in ground school last
night, but went about it in such a way we all pretty much got lost
halfway through it. I thought perusing my 3 pages of notes would shed
some light on it, but my results aren't "meshing" with the D.A charts
in my P.O H - they're quite a bit off as a matter of fact.

I've called 3 of my fellow classmates and they're just as confused as
I am. A nice easy way to figure it out would be appreciated and maybe
a condensed explanation as well. I've got a pile of textbooks to
peruse for more details..

Thx!