noob on schedule customizing

[rameus]

My wife and I have been running KSan for a while and she was ready for more challenge for Ground. I updated the Ga and the schedule for commercial flights by adding more departures. This totally backfired and I ended up inundated with many more inbound flights than I had before when running the same time period. However, it worked for her during that time because she had more departures which I had worked into the schedule.

Why did I get more inbound flights when all the flights I added to the schedule were only departures, no new arrivals?

 

[Braf123456]

I’m the for example is it like this alt, San, 752, dL, 1213, 13:45, 12:00, 1, dL or is it like this San, Atl,  752, dL, 1214, 12:00, 14:45, 1, dl

[Braf123456]

For arrival the the airport where it took off goes first lol the flight took oof from Atlanta for departures the airport that the departure is leaving from an for your case it would be San Diego 

[rameus]

I thought for certain it was, dep-arpt, arr-arpt, fltnum, arrtime, deptime in the schedule file. Ga is different syntax.

So yeah, in this case San, Atl, aa431, 17:45, 12:00 ....

That explains the inundation - I had it backwards. Thanks!

 

[Braf123456]

2 hours ago, rameus said:

I thought for certain it was, dep-arpt, arr-arpt, fltnum, arrtime, deptime in the schedule file. Ga is different syntax.

So yeah, in this case San, Atl, aa431, 17:45, 12:00 ....

That explains the inundation - I had it backwards. Thanks!

 

No problem 

[rameus]

I just tested this in San Diego.  I didn't have it backwards.

Am I way off here?  This is what I'm seeing:

// KSAN_SCHEDULE.TXT
// dep_arpt, arr_arpt, aircraft, airline, callsign, arrival_time, dep_time, dur, airline

SAN, IAH, 739, UA, 1593, 12:00, 11:47, 1, UA

See screenshot.  This is a departing flight from KSAN (currently controlling) destined for Houston George Bush Int'l, pushback approved at KSAN at 1147.

 

That doesn't explain why I encountered so many more arriving flights, when I added a lot of departures from KSAN.  I added 18 flights.  2 of the flights are new arrivals, the other 16 are departures.  Why did I have many more arrivals than I did when I didn't have any of these changes?  Does T!3D Pro look for corresponding arrivals of these added flights and make arrivals for them if it can't find them in the schedule?

[Braf123456]

could you post some of the arrivals

[hexzed]

Only the flights in the schedule will appear, but they may appear in different orders and at different times depending on gate availability, and arrival spacing restrictions.

You will find all those flights somewhere in the schedule.

[rameus]

Here is a difference analysis showing all of my changes (red text lines).  I also included the modified schedule.txt.  Thank you for checking it out.

ksan_schedule.txt

 

ksan_changes.pdf

[ac455]

Like @hexzed said above, flights occur based on gate availability. According to your KSAN changes file, you've added a lot of extra flights for departure between 17:00 and 18:00. Once these additional aircraft have called for pushback, the sim looks to fill the now empty gates; giving you a much higher amount of inbound traffic.

[pete_agreatguy]

Not sure if it useful but these are the layouts for the "icao_schedule.txt" and "icao_gaandlocaltraffic.txt":

Quote

 

Schedule:

airport departure iata code,airport arrival iata code,aircraft type,airline iata code,flight no,arrival time,departure time,duration,codeshare

Duration usually is set as 1 and codeshare needs? to be the same as the airline iata code.

 

Quote

 

GA:

origin airport icao code, destination airport icao code, time, aircraft type, linecode, stop n go, touch n go, low approach, callsign, spoken callsign

 

Never understood why the layout was chosen this way personally. A lot of inconsistency and illogical coding in place.

i.e. The use of iata and icao codes - why not just stick with one across the board ... and ... arranging the arrival and departure times the opposite of the airport codes.

[rameus]

6 hours ago, ac455 said:

Like @hexzed said above, flights occur based on gate availability. According to your KSAN changes file, you've added a lot of extra flights for departure between 17:00 and 18:00. Once these additional aircraft have called for pushback, the sim looks to fill the now empty gates; giving you a much higher amount of inbound traffic.

Where does it pull flights from to fill those empty gates? If they're not scheduled to arrive does it generate them? Or does it scan through the schedule file to find flights to move from a previous arrival time into the current time slot?  This is outrageous. Why wouldn't it just stick to the schedule?

[ac455]

1 hour ago, rameus said:

Where does it pull flights from to fill those empty gates? If they're not scheduled to arrive does it generate them? Or does it scan through the schedule file to find flights to move from a previous arrival time into the current time slot?  This is outrageous. Why wouldn't it just stick to the schedule?

The sim will always stick to the schedule file,  it also never change times of flights. The schedule that comes the Real Traffic already has more flights than gates programmed into it. A lot of the new arriving aircraft that you are seeing were previously dropped because there was originally no free terminal for them to go to. This is something that happens regularly at all airports and is something that has been debated about on this website before.

 

[rameus]

2 hours ago, ac455 said:

A lot of the new arriving aircraft that you are seeing were previously dropped because there was originally no free terminal for them to go to.

Can you explain this more or better yet, link to a discussion about it where I can learn more about this? This sounds more like what could be actually happening.

[rameus]

4 hours ago, pete_agreatguy said:

Not sure if it useful but these are the layouts for the "icao_schedule.txt" and "icao_gaandlocaltraffic.txt":

Never understood why the layout was chosen this way personally. A lot of inconsistency and illogical coding in place.

i.e. The use of iata and icao codes - why not just stick with one across the board ... and ... arranging the arrival and departure times the opposite of the airport codes.

Pete,

Roger that. I agree but I don't think this is directly affecting my confusion.

Rameus

 

[ac455]

1 hour ago, rameus said:

Can you explain this more or better yet, link to a discussion about it where I can learn more about this? This sounds more like what could be actually happening.

I can't seem to locate a specific topic on this, but I have read about this before, specifically for KLAS. However it will also affect all airports as it is just the way that the game engine works.

Ill try and do my best to explain the situation:

When a flight calls for a pushback, the sim looks in the schedule to see if there is a flight that can replace it as the gate. Without any modifications to the schedule, some of the inbound flights would not have a gate to go to because of all the traffic idling at gates; and because there is more inbound flights than gates. When the sim recolonizes their is no gate for a flight, it will simply delete the flight from existence. In the output log file, this can bee seen with an error showing "no free terminal" with its call sign.

Since you added a bunch of extra departing flights in a short time, these "no free terminal" flights can now be assigned a gate; allowing them to come in. With the extra flights now coming in, shooting gaps at KSAN becomes nearly impossible.

As others have said on this website, the only way to fix this issue is to use snippet files from custom schedules that be be found on this website. A snippet file is simply a schedule file that has flights for only 3 hours, not an entire day worth of flights.

[hexzed]

Adding to this, it will also depend on how many arrival runways are open as well. 

Tower assigns an inbound flight about a minute behind the previous one. On single runway like San Diego, they will stack up behind each other, but at Atlanta, if you have 3 arrival runways open you will get the arrivals flowing in a lot better.

As ac455 says, try cutting 1 or 2 hours out of the schedule, and you will notice that the schedule times are followed a lot more accurately.

[DeltaVII]

2 hours ago, rameus said:

Can you explain this more or better yet, link to a discussion about it where I can learn more about this? This sounds more like what could be actually happening.

You can verify what @ac455 says, if you start Tower 3D from the installation directory using the "tower3d.bat" file. After you're done there will be a "game.log" file in that directory. Open it with WordPad or a similar text editor and you will find a lot of messages stating "***** no free terminal". Those are flights on hold at a waypoint outside the aerodrome's area, if you will.

Tower 3D, as it is constructed, always needs an endpoint for arrivals. You can try it out when all gates for a ramp are occupied - there will be one call for push and start and a corresponding arrival calling in shortly after. Just let the departure sit at its gate without issuing a push instruction while the arrival lands. Then try to give taxi instructions to the gate. The PIC (or his/her FO) will respond "Negative, gate is not available" and stay sitting at the runway exit. As soon as you issue the pushback instruction to the delayed flight, you can give successful taxi instructions to the arrival. As long as there's no pushback available to open up a gate, arrivals to that occupied terminal are delayed.

(The solution for this is on the wishlist for the next major version of Tower, which is "progressive taxi". This means you can send the aircraft on any way to any holding point on the airfield, until the gate opens. That holding point could even be an intersection on an inactive runway, as far as our wishes go. This is what happens in real life. One aerodrome where this is a very common occurrance is Kennedy. You may have already noticed, if you know the "Kennedy Steve" videos on Youtube.)

[crbascott]

Actually what happens in the sim engine is slightly different than what @ac455 describes above.

Arrivals do not get deleted - the "no free terminal" error just means that at this point in time there is no gate available. The engine will continuously check (originally it was every 15 minutes but was improved to check every minute or two) to see if a gate frees up. If you look at a log file, this is evidenced by the many "no free terminal" messages for the same flight. If/when a gate becomes available, the arrival will spawn.

After you press start (and not at pushback) is when the internal tracon (as FT likes to call it) determines the departure scenarios for each flight in the schedule (up to 8 hours). If there are not enough gates available to handle all the departures, then a departure could get dropped and you'll see a message like "Airplane dropped, no declared terminal". A departure could also never spawn if the tracon makes it dependent on an incoming arrival. You'll see these flights in the log file labelled as "Restarter airplanes". Again, this is done in the loading process so you'll see this "early" in the log file. 

The more flights that are loaded at the beginning the bigger the chance for some to not appear. That is why I was the first custom schedule maker to provide schedule snippets to combat this issue. Now most other custom schedule makers do the same whether they call them snippets or not. As they say, "imitation is the sincerest form of flattery".

Also, as an FYI, you do not need to run tower.bat to get a log file. After your session you'll find a log file called output_log.txt in the tower3d_Data folder.

 

[rameus]

This is all very helpful. I'll do some investigating. At the time we've been controlling I seem to remember a good number of open gates but I'll confirm that.

Thank you for the tips. I'll try removing a few hours and even try a three hour segment schedule file. Some wonderful things here to try.

Does Tower correctly mimic the gates as in the real airport so I can do some number crunching on availability?

Edited March 6, 2019 by rameus
+ question

[crbascott]

8 minutes ago, rameus said:

Does Tower correctly mimic the gates as in the real airport so I can do some number crunching on availability?

I wouldn't say correctly, but it is somewhat close. Fixing gate definitions and other issues are definitely something needed in the next version. 

[hexzed]

You can adjust the Terminal file to better represent airlines at the terminal level, but not at gate level

[crbascott]

6 hours ago, hexzed said:

Tower assigns an inbound flight about a minute behind the previous one. On single runway like San Diego, they will stack up behind each other,

Using a single arrival runway it is roughly one minute and 30 seconds - the sim enforces 5nm separation between arrivals (at the initial DBRITE appearance). As a result, in my experience the maximum number of arrivals you'll see in a hour using a single arrival runway is roughly 42-45. 

[Leecedar]

I'm using a schedule maker program, and wanted to alter some of the local traffic to include more maneuvers.  I just looked at the schedule that it made, and can't tell which flights are local, nor do I see anything different in any of the flights to indicate maneuvers.  Can somebody tell me the syntax that indicates local flights, and the syntax for local maneuvers?  Thanks much!

[pete_agreatguy]

Local flights are found in a separate file (kjfk_gaandlocaltraffic.txt), compared to the schedule file (kjfk_schedule.txt).