Flytec 5030 v2.24 * - Manual (Page 44)

Flytec
5030 GPS
naturally have to use the same units).
When the Flytec 5030 GPS is turned on, the polar curve entered is calculated and stored in
the unit's memory as a very precise chart. At every flight speed the unit knows immediately
how strong the associated sink rate should be. If the sink rate measured by the vario,
amounts to more than the charted value, the pilot will find him/herself in sinking air. If, for
example, the vario announces, with the below mentioned paraglider, a sink rate of only
0.5m/sec when flying at 35 km/h, then the pilot needs to be located in air rising at 1.3-0.5=
0.8m/sec; this is also shown by the netto vario. (See 5.2)
Because the Flytec 5030 GPS knows the rise and sink rate of the surrounding air mass, it
can continually plot new tangent lines to the polar curve in order to indicate the speed of the
best glide in any situation.
Polar curve of a high performance hanggliders: Polar curve of a high performance
Paraglider
Best L/D: 47/(3.6x1.2)=10.9 Best L/D: 35/(3.6x1.3)=7.5
In the example for the hang glider above, the dashed line of the tangent is assigned a sink
rate of the air mass of 2m/sec. The required speed related to this is 63 km/h. The required
speed is the speed indicated which allows the pilot to fly constantly at the best possible glide
ratio. He/she will, i.e. arrive higher at a valley crossing than his/her colleagues, who are only
flying according to feel (during the same conditions).
The pilot flies, in the example to the right, much too slowly because he/she stays too long in
the sinking air; he/she will lose both altitude
and time. If the pilot flies faster than the
instrument's recommended speed of 62
km/h, then he/she would arrive lower than
his/her colleague, who is flying at the
optimal speed of 62 km/h. In the paraglider
polar curve shown above the dashed
tangent line is drawn for a head wind of 20
km/h. The best glide is given at 38 km/h. If
the pilot flies with an activated GPS, then
this increase in the best air speed will
automatically be taken into consideration by
the required speed arrow.
0 Bat. 3.57V 12h
4
3 2
1
m/s
1
2 3
4
70
50
40
30
m
60
+
INT
In contrast to sailplane gliders for which the manufacturer's measured polar curve has
validity for a long time, with hang gliders and more so with paragliders the polar curve is
dependent on the age of the surface, the condition of the sailcloth, the weight of the pilot,
his/her harness, and other factors. In order to realize the best possible speed during a later
flight, it is necessary to input the polar curve as accurately as possible, which means, it
should be determined by the pilot. It is obvious that such a measured flight will bring the best
results in stable air conditions.
Particularly interesting are value pairs (speed and its associated sink rate) in the upper third
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