Rookie Operational Question

[NovemberBravo]

In some airports on my Tower!3d Pro it's simple to keep the departing plane in the right order compared to the slot order in others like Philadelphia it's harder. 

It is it a set rule that departing aircraft must depart in the same order as their slots? 

I know I can get planes to take off in any order I like but I am interested in good operational practice. 

 

Thanks for the guidance. 

NB

[DeltaVII]

That's quite impossible to answer, because in reality the crews don't have a fixed order like in Tower schedules. But as far as I know the most relevant parameter when it comes to the departing order is the SID (if possible), trying to balance the timing versus wake turbulence. Of course, this is more difficult in congested airspaces like JFK, where you mostly have just one direction to release the planes, and a little easier in more open airspaces like Dubai where you have loads of directions to turn the departing aircraft to (from 12R: 090 to GETID/DAVMO, 120 to ANVIX, 209 to MIROT/KUTLI/EMERU/RIDAP/SENPA/NABIX; from 30R: 359 to GETID/DAVMO, 235 to ANVIX/ITOTU/MIROT/KUTLI/EMERU/NABIX, 299 to RIDAP, 266 to SENPA; or omnidirectional from each runway up to 90 degrees to the right or left).

[Avwriter]

I do not believe that there is an absolute rule in regard to this, and is certainly not the same at every airport.  In my observation, there is usually a balance that controllers try to strike between trying to be fair by getting planes off in the approximate order of their scheduled departure/actual pushback times ( which themselves vary a lot in different circumstances), vs. simply clearing the deck as efficiently as possible; this often means giving priority to planes that are obstructing other planes, sequencing for wake turbulence (heavies may be held back if there are a several smaller aircraft in queue nearby), or which aircraft  are simply closer to the runways and so can be moved out faster.   Some departures will  even get clearance sooner because an arriving plane will need that particular gate.  There are a lot of factors at play, and the priority will even vary from one day to the next depending on what is going on.

 

Andrew

[MJKERR]

4 hours ago, NovemberBravo said:

In some airports on my Tower!3d Pro it's simple to keep the departing plane in the right order compared to the slot order in others like Philadelphia it's harder. 

It is it a set rule that departing aircraft must depart in the same order as their slots? 

I know I can get planes to take off in any order I like but I am interested in good operational practice. 

I started with Tower 2011 EGLL (Heathrow) in 2019 
For each summer from 2016 to 2019 I was lucky enough to stay at a hotel nearby with an excellent view of the holding points for Runway 27R departures
Even after four years I still could not quite work out the order the aircraft queued at A1, A2, A3, A4 and A5 were going to be cleared on to Runway 27R

In general two smaller aircraft (A320 and B737) would be cleared between each heavy, if appropriate
That assumes one was on A4 and in the correct order at A1/A2/A3
As above, sometimes that was not diserable as the SID was the same

In the summer of 2019 I sat at Primrose Hill (London) twice
On the first occasion I watched departing aircraft, and the separation was about 15 minutes
On the second occasion it was sadly arrivals but I did notice the same general aircraft type pattern was being applied
I also started using flightradar when staying at the hotel and this made it much easier to predict departures

I started with Tower 3D and OMDB (Dubai) in June (I chose Dubai as I prefer international Heavy aircraft) 
Sadly I have never been to this airport
I started off with charts and then watching a few videos on YouTube
It was then pointed out that departures are predominantly Runway 30R, so is similar to Heathrow

At OMDB I have a fairly good process now for accepting arrivals and dispatching departures
In some cases I can have three aircraft all lined up ready for departure
B737 from N8 or M12A, then B777 from M13A, then A380 from M15A

Equally, I can end up with aircraft out of sequential order so that they can cross runway 30L
This is usually a B737 at K7, B777 at K10 and A380 at K12
I try to get this so setup in advance so that there is no queue back on to taxiway K
I have had this once, so cheated and sent the aircraft on a long route to K14, R then to N12
That is not something you can do at EGLL !

Personally, so long as an aircraft departs within 15 minutes of leaving the gate it is acceptable
From memory there is penalty if it is excessively late departing

[crbascott]

In real life, departure sequencing is much more than just a local process - at least from an FAA perspective.

This first link is an older overview of traffic flow management. https://www.fly.faa.gov/Products/Training/Traffic_Management_for_Pilots/TFM_in_the_NAS_Booklet_ca10.pdf

This second link is today/tomorrow. https://www.faa.gov/air_traffic/technology/tfdm/

I found the TFDM video to be very interesting as well as the associated TFDM links.

Obviously with T!3D we don't have nearly enough information nor the tools to sequence things properly. Hopefully the next version will at least bring us somewhere close to current day technology. 

[DeltaVII]

15 minutes ago, mjkerr said:

Personally, so long as an aircraft departs within 15 minutes of leaving the gate it is acceptable
From memory there is penalty if it is excessively late departing

Only if you choose to ignore the ready-for-push or ready-for-taxi. As soon as it's taxiing, you're absolutely fine. At JFK, I honestly had taxiing times of more than an hour before departure, and I was fine. I even upped the ante by deliberately declaring a certain region not available for some time due to severe weather - in reality those planes would mostly not even leave the gate (as Kennedy Steve put it: "I'm not going to make your problem my problem, unfortunately"), but I let them taxi from the gate to an unused taxiway or runway and just park them there until my declared release time came.

[MJKERR]

12 hours ago, DeltaVII said:

I even upped the ante by deliberately declaring a certain region not available for some time due to severe weather - in reality those planes would mostly not even leave the gate

I assume this is a hypothetical game addition (as I have not yet applied the weather option in Tower 3D)

At EGLL in most cases departures are processed normally, due to stand demand
The aircraft is then either -
left near to the terminal, in case it is highly likely it will be rescheduled
sent to a lightly used taxiway that it will not obstruct other aircraft, where it is likely to take off eventually

In Summer 2019 I saw this twice
BA flight to Hamburg left the stand as normal and then sat for nearly 90 minutes at Link 57
AC flight to Montreal was third to depart from Runway 27R, but was sent via Taxiway M (normally only used for maintenance) to sit near to Runway 27L at Link 28 for two hours (as by then the runway swap would have taken place)

[DeltaVII]

35 minutes ago, mjkerr said:

I assume this is a hypothetical game addition (as I have not yet applied the weather option in Tower 3D)

It's a strategy I just made up, completely independent from the weather settings in Tower!3D. In that particular case, my imaginary scenario was a severe storm hitting Florida and the Bahamas for the next almost 90 minutes after starting the game, so every flight to KMIA, KFLL, KPBI, KRSW, KTPA, KMCO, KJAX, and MYNN was delayed. I was using 13R for departures. I taxied all those flights from the gates to 22R@F, lined them up there, then gave a new instruction to taxi to 13R via J (which caused them to taxi on the runway) and let them hold short of either J, H, G in groups so that the crossing taxiways remained free. Each was stopped by a HOLD POSITION command. After the timeout was over (the new release time minus 15 minutes for the taxi and re-organisation), I gave each one of them the taxi instructions via J, A, Q to PF, weaved them back into the sequence and released them.

Everyone can do it this way with pretty much every airport (even KLGA...). It's completely arbitrary. You only need to stick to your own concept.

[NovemberBravo]

Thank you all for all the feedback thoughts and guidance (and links), it's much appreciated. Incidentally, I live in the middle of the NW EGLL arrivals stacking area. Also any flights to North America leaving on 27L or R fly over head between 8,000 and 10,000 feet. 

As you can imagine it's been quiet here over the last few months. 

 

Thanks again!

Cheers

NB