LXNAV LX8000, User Manual

Page: 56 / 110

LX8000 (LX8080) Version 2.6 September 2011
Page 56 of 110
In the lower left corner of screen a wind symbol is displayed. The arrow indicates the wind
direction relative to the map orientation. Wind direction and wind speed are numerically
presented below the arrow.
In the bottom row several items are displayed.
Thermal
shows the last thermal average,
Brg
is the bearing to the selected target,
Dis
is the distance to the target and
Alt
is the
current MSL altitude.
The last two numbers (
reqE
and
E)
show the required glide ratio to the target. In the
above example the required glide ratio is 7 and current glide ratio is 58. The current glide
ratio is calculated over the last two minutes of flight.
5.5.1.1 Final Glide Symbol
The final glide symbol is a complex symbol. The bottom number (+1202 in the above
example) shows your predicted arrival altitude. Negative numbers indicate that you are
below the glide path and positive numbers indicates you are above the glide path. In the
above example the glider is above the glide path. Chevrons show the position relative to the
required glide path in percents. One arrow means 5% above or below final glide. In the
example 25% above glide path is shown.
The middle number is the current MacCready setting. In task mode it is prefixed with the
letter
T
,
A
,
B, G, S
or
AG
. See Chapter 7.2.1 for detailed explanation of this mode.
Sometimes there will be another number above MacCready which is used for arrival over
terrain. If we are on final glide to a selected target but between it and the current position
there is terrain which cannot be crossed without more height, then this number will give us
an estimate as to how much we have to climb to pass over the terrain. A red rectangle will
also be shown on the magenta line indicating the point of potential collision.
5.5.1.2 Thermal Assistant
During thermaling the wind symbol will also shows the thermal assistant. The thermal
assistant continuously analyses the thermal whilst circling. The sizes of the dots indicate the
strength of the thermal. Big dots mean stronger lift at that point. On the left or right side of
the circle a small airplane symbol is shown. This airplane indicates your position. A black
dot indicates the thermal maximum. The pilot should extend the circle when the black dot is
about 60° away from glider. This value varies and depends on turn rate of the glider and
type of thermal. All other dots are coloured based on the MacCready setting. Red colour
means values above MacCready, blue values below MacCready and yellow dots represents
lift about the same strength as the MacCready setting.
This colour scheme gives us hints about a thermal at glance. If most of dots are red we
should consider increasing the MacCready value; if most of dots are blue we should consider
decreasing the MacCready setting.