LXNAV LX8000, User Manual

Page: 48 / 110

LX8000 (LX8080) Version 2.6 September 2011
Page 48 of 110
5.1.12.8 Engine Noise*
The current engine noise level is shown as a progress bar. Use this menu to display your
current engine noise.
5.1.13 Polar and Glider*
Use this dialogue to enter glider polar and other glider properties. As default polar a
standard class glider is selected.
Polars for most modern gliders are already prepared. Press the
LIST
button and a dialogue
with a list of all available gliders will be shown.
Select the required glider using the lower-right knob and press the
SELECT
button. All
glider data will be copied from the chosen polar. You may quickly check the best glider ratio
and minimum sink rate to see if the polar data matches the glider performance. You can
modify the polar by changing coefficients
a
,
b
and
c
. A polar is defined as a quadratic
equation with the parameters a, b, and c. Use the LXe program (Tools->Polar) to calculate
coefficients a, b and c for a given glider’s polar. The program requires three sink points
entered at selected speeds (e.g.: 100 km/h, 130 km/h, and 150 km/h). The program will
calculate the values of a, b and c, which should be noted and entered into the LX8000.
Stall speed
is used to generate stall warnings which are available only with the LX Voice
module.
Weights must be entered if user enters ballast in kilograms. There are three weights to
enter.
Min.weight
corresponds to the min.load value and represents the value at which the
polar was measured or recalculated.
Max.weight
is the maximum take-off weight allowed
for a glider. It is not used in the calculation; it is just a reminder to the pilot of the