At the Green Swamp Sport Klassic we had one goal with a nine
kilometer goal cylinder and another with a twelve kilometer goal cylinder. If
you are watching your Flytec 6030 or Brauniger Compeo+ as you fly toward goal it
becomes very obvious that the L/D required to get to goal is using the center of
the goal cylinder and not the edge of the cylinder which is actually what you
care about.

Steve Kroop <<info>> writes:

As far as I know there is no way to get arrival numbers (altitude
or L/D) to the cylinder boundary. A long time ago, when I asked Erich/Herbert
about this, the reply was that in their opinion, goal cylinders greater than
typical 400m (e.g., 1km) are called because of safety concerns about the landing
options at goal. For this reason they did not want to help create a possibility
where pilots doing a typical final glide (with little/no reserve altitude) would
be arriving with no safe landing options.

This does make sense to me and in a 1km goal cylinder situation the faster plots
will make a mental correction to final glide based on their knowledge of the
goal area. Correct me if I am wrong, but it is rare to call a task with much
more than 1-2 km goal cylinder other than at a lower key comp like the Green
Swamp meet and I don’t think that the Erich/Herbert anticipated this type of
application.

I am copying this to Joerg in the event he knows of a clever work
around for this situation other than making a WP on the cylinder which is really
only doable with a laptop and really not very useful since I presume one of the
reasons for the big cylinder as uncertainty about the weather conditions and the
approach to goal may differ considerably from the line between the last TP and
goal. In the future I suspect the could be a data-field: L/D to Cyl or L/D to
optimized WP.

Joerg Ewald <<joerg.ewald>>
writes:

I had lengthy discussions with both Erich and Herbert on this as
well, because I got caught by this as well in the past. The thing is, to know
the L/D to a specific point, you need to know the altitude at that point. Now,
in a comp in Florida, that’s easy, most likely, even 12 km out, the altitude is
the same as the altitude at the waypoint itself. Not so much in many other, less
flat, regions on this planet.

On the 6030, I doubt we will be able to include elevation data, but we’ll look
into it when we implement those for the Connect 1. Once we have that data
available, we can use it to calculate L/D required to any point on the map, even
accounting for ridges that may stand in the way.

In the mean time pilots can put in temporary goal points at the
edge of the goal cylinder if it is especially big.