Tower!3D Pro - Arrival Volume Question

[crbascott]

Vic,
I am finding that the Tower!3D Pro engine does not handle two arrivals at the same time. In other words, if the schedule has two arrivals at 10:00 one of the two arrivals will be delayed. This occurs even if multiple (simultaneous) arrival runways are selected. As a result, I believe the maximum number of arrivals we can possibly see in an hour at any airport is 60. Can you confirm if this is in fact the case?

With a minimum separation of 5nm (which Pro has inherited from 2011), we determined the maximum arrivals for a single runway was around 42. As a result, I was hoping we could see as many as 80+ arrivals on airports with two active arrival runways and something in the range of 120+ at KATL and other airports where three arrival runways could be active.

For a refresher , the following is a link to a topic we discussed arrival capacity in Tower!2011 and how this part of the system would be rewritten from scratch  for Pro.  http://forum.simflight.com/topic/81525-tower-2011-arrival-spacing-decrease/ 

As people use Real Traffic with real traffic volumes, continue to make realistic custom schedules, and use the schedule creator to "max out" the number of flights; it would be helpful to know what hourly arrival volume parameters we have with Pro.

Thanks,
Craig

[FeelThere_Vic]

Hi Craig,

I doubt there is an artificial limit in the schedule or an arrival time limit but I will check with our programmer. I for sure saw many parallel approaches during testing so I'm positive they are used. Do you have any data that we could look into?

 

Vic

 

 

[crbascott]

Parallel approaches are definitely used - which is a nice upgrade from 2011. This has increased the hourly max arrivals from 42ish to 60. 

I'll follow up with some schedules and logs from KLAX that should help confirm the arrival/schedule capacity limitation.

Thanks,
Craig   

[FeelThere_Vic]

Thank you Craig.

 

Vic

 

[crbascott]

VIC,
I conducted a couple of tests at LAX in order to provide data regarding arrival capacity.

TEST INFO

Test 1 - I created a schedule file that had 60 scheduled arrivals at 1 minute intervals beginning at 10:00. Theoretically, each arrival should alternate between 25L and 24R.
Test 2 - The schedule file had the same amount of flights and  in the same order as Test 1. But for this test there were 2 arrivals every other minute (two at 10:00, two at 10:02, etc.). 

Both tests included a departure at 09:59 to "prime" the sim engine. 

RESULTS (details are in the attached spreadsheet):

Test 1 - All 60 arrivals appeared as scheduled and used the expected landing runway. This demonstrates that simultaneous arrivals runways are definitely used. However, the schedule must be built strategically in order to experience the maximum hourly arrivals of 60. At 11:10 all planes were parked, the strip was empty, and the session was ended.

 

Test 2 - At no point did any of the flights with the same scheduled arrival time appear simultaneously on the DBRITE. The pattern of flights was not nearly as consistent as the first test - including flights arriving in a different sequence and using different runways. Some flights appeared on the DBRITE over an hour after they were scheduled. At 11:51 58 planes had landed and parked successfully, the strip was empty, and the session was ended. 2 flights had not appeared yet but I hope/assume they would eventually show up.

CONCLUSION

The sim engine has employed simulaneous arrivals, which is an upgrade from Tower!2011. However, the maximum number of arrivals in an hour is 60 apparently due to the way the sim handles the schedule - specifically flights with the same arrival time. Thus, we are unable to take full advance of real traffic and other realistic schedule volumes due to the arrival limitation. 

Let me know if you have any questions. I've sent schedules and logs via message.

Thanks, Craig

 

LAX_Arrival_Test.xlsx

[FeelThere_Vic]

Thank you Craig. We will look into this for sure, however if it's really a case please don't answer an immediate answer; it may require rewriting the schedule system which is most likely would be pushed to the next version of Tower!3DX. Let's see what will our programmer say about it.

 

Vic