Operation Manual

V3 Version 1.0 November 2012
Page 19 of 29
Polars for most modern gliders are already prepared. Use Glider type control, to list between
preloaded glider polars.
All glider data will be copied from the chosen polar. The check the best glide ratio and
minimum sink rate, to see if the polar data matches the glider performance, you may look in
MacCready setting menu. 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 SeeYou
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 LXNAV V3.
Stall speed is used to generate stall warnings which are available only with integrated Voice
module (Not integrated in LXNAV V3).
Weights must be entered and user should enter ballast in kilograms. There are three
weights to enter. Min. Weight (Minimum glider weight) corresponds to the min.load value
and represents the value at which the polar was measured or recalculated. Max. weight
(Maximum glider 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 maximum take-off weight. Empty
weight (Empty glider weight) is weight of the glider without pilot and ballast. The overload
factor is calculated as:
weightgliderMinimum
ballastWaterweightPilotweightgliderEmpty
overload
..
....
+
+
=
Empty glider weight is a weight of empty glider. This number can be found in a glider
book.
Pilot weight is weight of the pilot with parachute and baggage.
Water ballast is a weight of ballast.
Minimum glider weight is a weight of empty glider + minimum pilot weight. This value is
useful for when we want to display ballast in weight (kg or lbs).
Maximum glider weight is MTOW ( max. takeoff weight ) – this value is used only to limit
pilot to enter higher ballast, as is allowed with MTOW.
5.3.8 Password
There are several passwords which run specific procedures as listed below:
• 00666 Resets all settings to factory default
• 99999 will clean logbook
• 01048 can adjust needle to zero
Do not adjust needle when airborne.