Runway Data from Makerunways.

[cliffordagius]

Hi,

I am in the process of writing some software to act as an Instructors station for a P3D setup we are building into a mobile simulator. I was looking for a database of runway data similar to that supplied with x-Plane but couldn't find it and then stumbled across the great little MakeRunways app.

My question is about the data that is included and if it can provide any further information in future updates. I want to position the aircraft on the threshold of the runway but the Lat/Lon data returned is for the start of the runway so I am adding a bit to move the aircraft. This is also a problem for the accurate Glideslope touchdown position as there is no data returned for that and I wanted to show a trace that can be printed for the ILS.

Is there any plans to include this kind of data in the files, currently I am using the XML file and also the R4.csv file (Converted to XML) to get most of the data I need but it's the missing parts that I am making up but for some airports this will be wrong. For example the G/S & touchdown at most airports is inset 300m but at EGLC it's just 150m but that is local knowledge and not possible to account for in all the airports of the world.

Any I'm just asking and it's a fantastic app and i'm shocked it's free.

Cliff.

[Pete Dowson]

My question is about the data that is included and if it can provide any further information in future updates. I want to position the aircraft on the threshold of the runway but the Lat/Lon data returned is for the start of the runway

But the offset to the threshold is also provided.

so I am adding a bit to move the aircraft. This is also a problem for the accurate Glideslope touchdown position as there is no data returned for that and I wanted to show a trace that can be printed for the ILS.

There's no separate position for ILS touchdown that I know of. I think it uses the threshold.

For example the G/S & touchdown at most airports is inset 300m but at EGLC it's just 150m but that is local knowledge and not possible to account for in all the airports of the world.

The R4.CSV file you say you are using gives 400 feet as the offset for the default FSX EGLC. The accuracy will be as good as the data in the scenery. I suspect the UK2000 or Aerosoft add-on EGLC's will be more accurate.

Regards

Pete

[cliffordagius]

Hi Pete,

Thanks for the reply. If we take the Lat/Lon for 27L at LHR and I position the aircraft there it is actually on the grass just at the start of the runway and not actually on the threshold. You mention the offset but this is only found where there is a displaced threshold and most of the runways display 0.

As for the touchdown point I will just use the standard 300M and for special airports like EGLC I will hand edit them and live with that.

Can I ask as well why there is some many different files all with varying degrees of information and not one files that contains it all, the XML file contains a lot but then I am forced to read in the R4.csv for the rest. It a great little app and I am only nit picking ;-)

[Pete Dowson]

Thanks for the reply. If we take the Lat/Lon for 27L at LHR and I position the aircraft there it is actually on the grass just at the start of the runway and not actually on the threshold. You mention the offset but this is only found where there is a displaced threshold and most of the runways display 0.

Not most of those I've looked at, includeing for example EGLC and EGCC and EGLL. The start points are those supplied by the BGL and where the FS airport menu would place you if you told it to start at a runway, so something is very wrong with your system somewhere. Maybe the BGLs are wrong?

As for the touchdown point I will just use the standard 300M and for special airports like EGLC I will hand edit them and live with that.

EGLC is just perfect on FSX. P3D must have messed up the FSX/ESP scenery files somewhere along the line.

Can I ask as well why there is some many different files all with varying degrees of information

Because MakeRunways started life in about 1995 and has been developed ever since mainly by me being a sucker and acquiescing to requests from all and sundry over the years. But no more.

Pete

[cliffordagius]

Pete,

Thanks it must be a P3D thing then that the positions are off a little maybe that's how it works in P3D, but I was under the impression that the scenery files between FSX and P3D where no different so not sure why the difference.

Never mind I have just taken your Lat/Lon data and move the aircraft forward 100m and that seems to be working fine now.

Thanks.

[Pete Dowson]

Thanks it must be a P3D thing then that the positions are off a little maybe that's how it works in P3D, but I was under the impression that the scenery files between FSX and P3D where no different so not sure why the difference.

Actually, i just checked, and remembered some things. What I said wasn't completely accurate.

The lat/lons for the runway ends are actually computed from the runway centre lat/lon (defined in the sceneries) and the runway orientation and length. So they should be actually on the border line, or very very close. This was changed from using the defined "Starts" because n a lot of airports especially add-on ones, the starts were actually at the hold position just off the runway (and with a 90 degree or other orintation to the runway). I think this was done as a more sensible position in most cases than placing aircraft directly on the runway. But it made a mess for programs like radar contact and others which were trying to line things up for an approach.

So, you should only need to adjust the position by the length of the aircraft to have it completely on the end of the runway. Add the threshold offset from the BGL and you are on the threshold.

You can actually read the "Starts" from the log, the Runways.txt file. At least I think those are the literal values from the BGLs.

Regards

Pete