VASI lights

#1
Went into lights, checked mark left and right VASI on the Primary properties tab, (Jensen, South Dakota), under World, dusk or nighttime selected, taken off from runway "S" heading north, turn back to the runway 180 degrees and there is a "ball of light" in the center of runway halfway down the runway. Coming from the other way, cannot see the ball of light nor can I see the vasi's. But earlier, I know that I did see the left and right vasi's but not now. Will continue to see if I can get them back.
 

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#2
hi Stu

Now with VASI we are still working on those to iron out a more friendly way of installing with drag capibilities.

Not sure about the light you are seeing so I am also going to do some test.

Keep us informed on what you see or don't see.
 
#3
Thanks. I did read where you guys were still working on them. What I'll do tommorrow is stay with Jensen and work and check out things.
I do love this program. I know you guys worked hard on it and I would like to say thank you for a wonderful and easy program to work with.:)
 
#4
Stu, that looks like the "ball" VASI or PVASI listed in the dialogue box. It's a drop down menu. Did you select one of those?
Don't know if this helps but Ball type is remapped to PVASI (pulsating) which is a single light. As you approach the runway it will pulse white if you are above the set approach angle (usually 3 degrees) and pulse red if you are below it.

In your screen shot it looks like the X bias is set to zero as the X bias is distance from the center of the runway off to the side (center of the runway width). The Z bias is from the center of the ruway length as I understand it.

Derrick
 
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#5
Stu, that looks like the "ball" vasi listed in the dialogue box. It's a drop down menu. Is "ball" the type you selected?
Hi. I selected VAS121, then VAS131 and another which I don't remember.
Tommorrow I'll select each one and see what happens. I did have them once tonight and they looked good. I'm going to work my way backwards of what I did and see if I can get them back.
 

scruffyduck

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#7
You should see a red bar on the airport where the VASI reference point it. If that bar is on the runway then you need to change the XBias as suggested. If it is not then it may indicate that some VASI types may offset from their reference point :confused:
 
#8
Thanks. I switched to TVASI and put some parameters in. In xbias, I put 100 and the ybias I Divided the length of the runway and subtracted 100 and now they are position good. Coming from the oposite way, I don't see the ghost light. :):D
 

scruffyduck

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Staff member
FSDevConf team
Resource contributor
#9
Thanks. I switched to TVASI and put some parameters in. In xbias, I put 100 and the ybias I Divided the length of the runway and subtracted 100 and now they are position good. Coming from the oposite way, I don't see the ghost light. :):D
OK good that it works
 
#10
Stu,

Here is a link to some more info on lighting systems.

http://www.faa.gov/airports_airtraffic/air_traffic/publications/atpubs/aim/Chap2/aim0201.html

The PAPI/VASI location on real runways is determined by data we don't have and that I couldn't compute if I did. My current method is to find a few sample runways that can handle the largest aircraft I hope to use on my runway and take that as a rule of thumb.

I hope to write a little bit up once I get it tested to see if it is a good principle.

Derrick
 
#11
Thanks for the link. I did learn a few things and did some more searches.
Red over Red and you are dead.
Red over White and you are alright.
White over White and you are to high.

I'm still using Jensen, South Dakota airport for all of my learning and testing.
I'm using vasi22 in the properties, primary (one end of runway) and secondary (other end of runway), left and right vasi's.
For parameters, I'm using:
Bias x 75 (moves off to side of runway)
Bias z 1100 (runway length 2400 feet divided by 2 equals 1200 minus 100 equals 1100 feet).
Spacing 200 (I have no idea if this is correct or not)
Pitch 3.5 (normally it would be 3.0, but have some trees at the end).

Going out and following the glideslope of the vasi, it put me right on landing threshold.

All of my settings are in natical miles and feet.
 
#13
On the Spacing setting...

the spacing applies to VASI only, not PAPI lights. It the space between the rows of lights on VASI. That is why it doesn't affect PAPI, since PAPI only has one row where VASI can have two or three.

From what I am reading the typical spacing is 300 feet.

Derrick
 
#16
Thanks Scott

Based on what I see I can use the touchdown bar to position the VASI closer or further away from the threshold based on a short or long runway.

The 700' can be 500 to 1,000 spaced which should give the FSX runway the slope angle for clearing objects.
 
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