Introduction
Landing perfomance figures are based on sea level air density at standard temperature. As elevation increases, temperature decreases at a standard rate. Air becomes less dense, resulting in lower performance figures. Temperatures varying from standard can have a drastic effect on landing and overall performance of your canopy.
A 2,000 ft elevation for a dropzone can suddenly become a 4,000 ft elevation dropzone as far as air density is concerned. This is called operational or density altitude - the calculated altitude of the air in which the parachute operates and is very important to know during our hot summers.
How to use this chart:
To determine conditions at your dropzone follow these steps:
- Enter DZ temperature along horizontal lines (example 25º C)
- Carry the temperature line to the right until it crosses the diagonal line of your DZ elevation (example 5,500 ft)
- From this intersection, drop a vertical line to bottom of chart. Read the operational or denisty altitude (example 7,800 ft)