Predictions of the wind can be made based on your previous glides; however, making predictions about the
amount of lift or sink on course is far less reliable. For this reason the lift and sink on final glide is assumed to be
net zero. Final glide consists of two phases, (1) Last Thermal and (2) Glide to Goal discussed in the following
two sections.
5.4.4.1 Final climb
Just as the 6030 knows the McCready optimized speed to fly for a next expected climb rate based your gliders
polar (as entered into the instrument), it similarly knows the correct speed to fly to goal based on your final climb
rate. For each speed to fly there is an associated glide ratio. Using this glide ratio, the distance and altitude of
goal, the 6030 can determine the necessary altitude you must attain in your last climb to arrive at goal by flying
the optimal speed. If there is a wind component, the 6030 can calculate your resulting glide ratio and adjust the
departure altitude.
The wind encountered on final glide can have a significant effect on your progress to goal, and in the worst case
can cause you to come up short. The 6030 automatically calculates the wind component and adjusts the final
glide departure altitude. However, the experienced pilot knows that there are circumstances where a manually
entered wind component would be preferable. If a manual head/tailwind is desired, press and hold the H/T wind
key for 3 seconds; the Information Field will now show “HT wind auto”. Press the F2 key, and the Information
Field will show “HT man.
!"
”; use the !" keys to set the desired head/tailwind in the Information Field (e.g.,
“HT man.
!"
-12” for a 12-mph headwind). When entering a manual headwind component, you must rely on
experience and expertise to determine a reasonable value based on the circumstances. To revert to automatic
head/tailwind press the F2 (Auto Wind) key.
As you climb in your final thermal, the 6030 compares the optimum (automatic or manual wind-adjusted)
departure altitude with your current altitude and displays this value in the user-field Alt a WP. The displayed
value will become increasing less negative as you approach the optimal departure altitude (Alt a WP = 0). When
this occurs the user-field visually inverts (white numbers on a black background) and it is now possible to leave
the thermal and fly at the optimum speed to goal. This assumes that lift and sink on final glide net zero. Because
there is no way for the 6030 to know otherwise – or to know if the wind component will change – you must
decide, based on an assessment of conditions, whether to leave immediately when Alt a WP = 0, or if it is
prudent to continue to climb for some reserve altitude.
In a strong thermal, when you climb to Alt a WP = 0, it means that you have climbed appreciably higher than the
altitude required to make goal at best glide speed. This extra height allows you to glide to goal at a higher
speed. However, if the last thermal is weak, the optimal glide speed is just a little more than best glide, and the
resulting calculated departure altitude will only be a little higher than that required to make goal at best glide
speed. Therefore you would have only minimal extra altitude, and a small area of sink could prevent you from
reaching goal without another thermal. For this reason you should climb to an altitude higher than Alt a WP = 0
if the last thermal is weak.
If goal is a line with an end-of-speed-section (ESS), calculating the optimum departure moment is slightly more
complicated. Scoring this type of finish, your elapsed course time is only until you enter the ESS, however, it is
still necessary to cross the goal line at the center of the ESS. To achieve the fastest possible final glide for this
type of finish you would need to climb high enough in your last thermal to fly McCready speed to the ESS and
then best glide to the goal line. As discussed above, when the optimized competition route is used, Alt a WP is
relative to the optimized cylinder intercept. If you leave the last climb when Alt a WP =0 you should have
suficient altitude to make the ESS but likely not enough to make the goal-line, therefore, it is clear that you must
climb higher than Alt a WP =0 in that last thermal. Since A BG WP is relative to the next point in the route and A
BG Goal is relative to the very end of the route, the difference between these two values (on the last leg of a
route) is the amount of altitude required to fly best glide speed from the second to last point in the route (ESS
intercept in this case) to goal. This means that if you climb the difference between A BG Goal and A BG WP
above Alt a WP =0 you should have suficient altitude to make the ESS at best McCready speed and then the
goal line at best glide speed.
If goal has a conical-end-of-speed section (CESS), in certain situations, it may be faster to climb up to the CESS
than to intersect it on glide. You can monitor the height up to the CESS in the user-field Alt Cone.
5.4.4.2 Gliding to Goal
Since the height needed to attain optimum final glide speed is based on the strength of the last thermal, you
should control your speed on final glide so that the McCready indicator lines up with the Average Thermal Climb
indicator. However, if your climb rate increases substantially in the last few minutes of your last thermal, the
Thermal Averager may not correctly reflect the overall strength of your last thermal due to the relatively long
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