Tas) True Airspeed / (Sas) Skydiver's Airspeed - Larsen & Brusgaard Military ALTITRACK Instruction Manual

Main Setup Display - Turn the Military ALTITRACK OFF - Delete Jump - Set total number of
jumps - Set total freefall time - Set current date - Set current time - Delete logbook - MPH / KMH -
Feet / Meter - (TAS) True Airspeed / (SAS) Skydiver's Airspeed - Canopy log Enable / Disable
- Dive Type - Celsius / Fahrenheit - Beep ON / OFF

10.10 (TAS) True Airspeed / (SAS) Skydiver's Airspeed

again to select "TAS/SAS"
Press
Fig. 12 - (TAS) True Airspeed / (SAS) Skydiver's Airspeed
Press to toggle between TAS and SAS
Definitions:
True Airspeed (TAS) and Skydiver's Airspeed (SAS) are two methods of calculating the
airspeed of a moving/flying/falling object.
TAS is a term used in aviation: It is the speed of an object relative to the surrounding air,
regardless of the altitude.
SAS is a new concept developed by LARSEN & BRUSGAARD: SAS is the speed of a skydiver
calculated from measurements of air pressure and temperature and converted to a fixed air
pressure (875.3 mb) and a fixed temperature (+7.080C) which corresponds to 4,000 feet ASL.
TAS
A skydiver's True Airspeed (TAS) relative to the ground changes as a function of the altitude (air
pressure) and temperature which makes it difficult to compare fall-rates.
Example: A skydiver (in a fixed freefall position) who has a terminal fallrate of
62 meters/sec at 10,000 feet will have a terminal fallrate of 50 meters/sec at 3,000 feet.
It will be seen that the difference in altitude (air pressure) makes it difficult to
compare the fall-rates when measured using TAS.
See paragraph 19 for more information about TAS and SAS.
NOTE: Jump data are continuously stored in both TAS and SAS. Stored information may be
displayed in either unit of measurement by selecting the respective mode.
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