Hi,

during planning I noticed, that the MSA ist different for identical but reversed legs.
e.g. BOT NDB to DOMEG shows only MSA 2.200, on the reversed leg (DOMEG => BOT)  it is 2.300. 
For the leg Essen to BOT (2.300) it is even 300 ft less on the reverse leg. Why?

(PC Version 3.6.0.0 & latest Android  Version)



Thanks & Regards
Jan

That isn't always a great solution. For example on a long leg, it would typically be quite undesirable to have the entire leg's MSA adjusted for one obstacle that is very much on the outside of a turn at one end. Although I do agree that it's a little unintuitive to have only one leg affected by it.

We can't do anything immediately about this as it's part of a core part of code that we have no plans to touch in the next couple of weeks (we're quite busy). I'm open to suggestions on this thread as to the best way to treat such obstacles, though, so we can address the issue in the best way possible.

On the contrary, it would be quite desirable! There is no difference between an obstacle being outside of a straight track and outside of a turn. If you set up SD to compute the MSA based on obstacles a certain distance from your track, it doesn't matter if you're on a straight line or in a turn. If anything, it is more critical in the turn since you don't have any course guidance in the turn itself.

If you have a long leg and there is a significant obstacle near one end which affects the whole leg, you can insert intermediate waypoints. Again no difference between turns and straight tracks.

Also, from a regulatory point of view, there is a minimum altitude for night VFR which is based on obstacles a certain distance away. This distance apply equally in turns as it does in when flying in a straight line.