"Strange" runway geometry

[Avi]

Hardy,

Do you mind to check the geometry of RW 26 in LLBG?
Just put yourself at the beginning of the runway and start taxi slowly. It seems that between the beginning of the runway and the landing threshold there is about a 10' hill which screws my landing. Can you explain it?
I checked it also with the previous NAV DB and got the same results so it probably has nothing to do whit it.

Thanks,

[Hardy Heinlin]

It has nothing to do with the nav database.

It's a side effect of the slope design in PSX since the first day.

When two runways cross that have extremely different threshold elevations, there will be a geometric conflict at the crossing point. PSX includes a special algorithm that smooths out this elevation difference as much as possible, optimized for the current aircraft track. I can't achieve a perfect model as I have elevation data just for the runway thresholds, not for every point on a runway (a sloped runway is not necessarily a straight line in the real world; it may have vertical S-curves). I still prefer this model over the flat model in other sims.


Cheers,

|-|ardy


I see a slight bump on the take-off position (as usual, I can't change it); I see no problem at all on the landing. Do you land on the take-off position or on the displaced threshold? The displaced threshold is the landing threshold.

[Avi]

Do you land on the take-off position or on the displaced threshold?

No, I land on the displaced threshold of course 
I did try to land closer to the threshold and this hill messes the RA callouts. It sounds like I'm falling from the sky.

Thanks,

[Hardy Heinlin]

I see no strange RA effect on the final to runway 26. Looks perfect here.


|-|

[Avi]

I'll check it again tomorrow.
Maybe I should have mentioned I did it with FSX and VisualPsx but since it wasn't for the first time I don't think it matters.

Thanks,

[Hardy Heinlin]

In flight, with external scenery in use, the elevation data is provided by the external scenery.

[ScudRunner]

Hi Avi,

I have seen the same issue you are reporting before - but ONLY with VisualPSX and FSX connected and only at a specific airport (YMML in my case) and even then only occasionally.

I have never seen it when using just PSX.

cheers

Scud.