MILITARY CYPRES USER'S GUIDE
Page 24
Airtec GmbH
4.4.1.1 Example of altitude adjustment in aircraft
(Military CYPRES with relative adjustment method)
Assume you are in a pressurised aircraft flying at an altitude of 20.000 feet (outside
air pressure approx. 466 hPa). The absolute air pressure inside the cabin is 898 hPa
(corresponds with approx. 3.300 feet ASL). The intended parachute landing point is
at an elevation of 10.000 feet (absolute air pressure 697 hPa).
For the altitude adjustment you require two absolute air pressure values, that at the
starting point (CYPRES calibration), and that at the landing point. In this instance the
starting point is the pressurised aircraft cabin (898 hPa) and the landing point is at
10.000 feet (697 hPa). The difference is 201 hPa. In terms of air pressure the landing
point is higher than the starting point and the CYPRES display must therefore show
201 after adjustment.
201
898
466
697
697
898
20.000 ft
10.000 ft
3.300 ft
0 ft
