I have postet this at the org too, because over there is the official support forum for the Airfoillabs B350. But I know about the knowledge floating here around so I try. When I follow the flight director on an ILS or RNAV approach in the B350 the angle seems right and I can fly down to the touch down zone and make a greaser landing. But the runways VASI shows 4 whites. If I switch to visual to have 2 whites and two reds, I come very low. That happens at many airports when flying the B350 but not with other planes. As soon as the runway is VASI equipped its always full white. Have you ever heard of such a funny thing? I think there’s something wrong with the view point in reference to the outside.

When you're seein the four reds/whites - low/high, what does your Glide Slope show?

4 hours ago, olderndirt said:

When you're seein the four reds/whites - low/high, what does your Glide Slope show?

If I see 4 whites it’s perfectly centered. If I see  red and white, glides lope shows I’m low.

Since the VASI is a visual aid and the glide slope is electronic, I'd go with the glide slope unless it plants you in an awkward spot.  There's nothing on an approach plate about how VASI's are supposed to look.

Edited February 28, 20206 yr by olderndirt

Yes, I will follow the glide slope indicator and the flight director. During visual approaches with no procedure available I will ignore those lights and follow visual judgement. Thanks for your help.

8 hours ago, Ralf Maylin said:

Yes, I will follow the glide slope indicator and the flight director. During visual approaches with no procedure available I will ignore those lights and follow visual judgement. Thanks for your help.

I was taught, long before VASI's, if the runway numbers move up in the windshield, you're low add some power - conversely, if they move down, your high take off power, slip or 's' turn as necessary.  After a while it becomes instinctive.

Edited February 28, 20206 yr by olderndirt

All good stuff.  It's common for the PAPI and glide path on an ILS to NOT be the same.

Hi guys,

very often in X-Plane the light installation for the VASI or PAPI are not in the correct spot...they are placed by volunteer scenery artists with varying degrees of skill and knowledge.

Sometimes it is impossible to see on the background satellite image we use to make the airports where exactly the installations are in real life.

Sometimes the location of the GS transmitter is also incorrect (it resided in a manually updated database and may not have caught a recent move of the real transmitter for that reason).

Sometimes the artist making the airport will place the lights adjacent to the "touchdown fixed distance markers" aka the 1000 foot point. Problem is that this marker in X-Plane is only vaguely accurate. X-Plane uses a handful of runway marking textures that are stretched as needed to fit the runway. So the 1000 feet markers are rarely at 1000 feet.

In conclusion: When doing an ILS approach, follow the GS. Chances are high that it is correct. Also keep in mind that you are not supposed to follow a PAPI or VASI when below 200 feet.

Cheers, Jan

 

Very well said Jan. HAPPY FLYING!!!!!

Thanks for all your answers, that all makes sense to me.