3 replies to this topic

[sr71_sr71]

Hi Folks.

I just started on a new airport, and am slightly confused on these references, so just wanted to check with you all.

When starting a new airport, we are asked to enter "ARP Lat/Lon", and when laying the runway we are asked for "Runway Center Location".

On the data sheet that I have for this particular airport, it kind of blends the 2 sets of values together. On my sheet (from the CAA) this is the airport location, but as you can see its also the runway center.  Here is the line I am reading:

"ARP Co-ordinates and site at AD:  Lat: 512032N Long: 0012046E  Center of runway"

My question is. Would you all enter this as both airport and runway center locations? Or do you all know a different method or rule?

With regards to the LAT and LON values, I would also like to confirm that I am converting these values correctly please. AFCAD asks for these values in the format of LAT: N##* ##.####' and LON: E#* ##.####', but my data sheet reads as Lat: 512032N Long: 0012046E.  Does that then make the values convert to: LAT: N51* 20.3200N' LON: E0* 01.2046E'?

One last thing.

Once an AFCAD is ready for deployment, can you all let me know if you are protecting them in some way? Copyright? Is there a way to protect them, maybe with a password? Does anyone take this route with these files? I personally will not be doing it, but just interested. This came from thinking about how people sell main airport scenery, as I presume they are using AFCAD to create these purchase products, but for some reason they are not viewable within the editor. Maybe there is more than one way to create these files, maybe a different application with a different format?

I look forward to hearing from you.

David.

[IBtheSarge]

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My question is. Would you all enter this as both airport and runway center locations? Or do you all know a different method or rule?

That is correct.  The airport reference point (ARP) and the runway center can (and often are) the same location.  Some airports identify the ARP as the exact center of the entire airport area, others simply use the runway center as the ARP.

Quote

With regards to the LAT and LON values, I would also like to confirm that I am converting these values correctly please. AFCAD asks for these values in the format of LAT: N##* ##.####' and LON: E#* ##.####', but my data sheet reads as Lat: 512032N Long: 0012046E.  Does that then make the values convert to: LAT: N51* 20.3200N' LON: E0* 01.2046E'?

Lat 512032N translates into N51* 20' 32" and Lon 0012046E translates into E001* 20' 46".  AFCAD does not specify the third value (seconds) but instead expresses it as the decimal value of a minute.  In the Lat set of numbers, 32" is 0.5333 minutes (32/60ths of a minute); so the AFCAD Lat would be N51* 20.5333'.  In the Lon set of numbers, 46" would equal  0.7666 minutes, yielding E001* 20.7666'.

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Once an AFCAD is ready for deployment, can you all let me know if you are protecting them in some way? Copyright?

AFCAD does not contain a password-protect option.  It's a freeware program and the scenery designed with it is freeware.  You will notice some legalese in nearly every freeware scenery available.  Those payware sceneries you refer to are generally nothing more than modifications of the default FS9 .bgl, usually containing only adjustments to ATC data.  Those sceneries that DO contain the runway, taxiway and parking apron data are created by payware programs such as Airport & Scenery Design by Abacus and other such programs.  The fact that AFCAD attempts to open and read them does not mean they are AFCAD files, only that they have been saved in .bgl format, which AFCAD also uses.

[sr71_sr71]

Hi.

Thanks for your answers, I think that really does clear things up.

I was looking over some existing bgl's and noticed they appear to be very much out of line with the real world Lat/Lon's for those airports, is there something I am missing when working with FS? I know its all just a game, but shouldn't these values align corectly? Is there an offset or something?

David.

[IBtheSarge]

sr71_sr71, on Jan 31 2005, 02:28 PM, said:

Hi.

Thanks for your answers, I think that really does clear things up.

I was looking over some existing bgl's and noticed they appear to be very much out of line with the real world Lat/Lon's for those airports, is there something I am missing when working with FS? I know its all just a game, but shouldn't these values align corectly? Is there an offset or something?

David.

LOL!!!!!  No, you're not missing anything.  That's what happens when a bunch of geeks and nerds in Seattle design EHAM, KJFK, et. al., without anything other than a photograph or maybe a couple of drawings in front of them.  They can't be bothered with precise locations of ILS localizers, glideslopes, runway headings, distance from runway centerline to ramp-side of the terminal, terminal length, etc.  They just stick things in and if it's "close enough" they publish it.    

That's why there's such a plethora of freeware modifications to airports worldwide ... Bill Gates isn't getting his money's worth out of those "program engineers" he has on staff.      They're doing just enough to get by without putting a lot of research time into it .... except maybe for SeaTac!  

On the other hand, however, with the number of airports, airbases, landing strips, private strips, etc., around the world, it WOULD BE kind of expecting too much for them to get them all correct.  (But between you, me and the fencepost, they didn't get enough of them right.   )

P.S.  When looking at the alignments, don't forget to take two things into account:

1.  Magnetic variation -- just because a building or parking spot faces "north" doesn't mean it's facing 360.  If the magnetic variation for that area is -16.3 degrees, to face north it would have to face 343.7 degrees.

2.  Runways are identified by the left-most one or two digits of their heading.  Runway 15, for example, would be approached by flying a heading of 150 (the last digit isn't used in the identifier) -- but not always.  Runway 15 could also be, in reality, a heading of 154 degrees.  There will be a notation in the map display that will show the runway identification (i.e, 15) and also a notation to fly a particular heading (i.e., 154) since the runway isn't REALLY on 150.

Edited by sarge, 31 January 2005 - 07:07 PM.