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QUESTIONS FROM THE DEVELOPERS


FeelThere_Vic

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Dear Folks,

We had many discussion about the taxi speed. Officially it should be 25kts or less but for so many requests for faster ground movement we increased it for Tower! 3D.
For Tower! Simulator 3 we would like to reduce it back to 25kts but we would also like to know what do you think about it?

Thank you

 

Vic

 

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In principle yes
The next issue is the variation between airports
There are also limits set by ICAO, EASA and aircraft type

Long straights - 30kt
Straights with objects - 20kt
Turns (dry conditions) - 10kt

Further into that are the rapid taxiway speeds, this can be up to 70kt, the limit is V1 speed so can easily be up to 100kt depending on aircraft type
In Tower 3D this is zero
Code 1 and 2 - 65kt
Code 3 and 4 - 93kt

As an aside an improvement / correction to aircaft separation would be helpful
There are a few times when a command is given to hold short of taxiway A
The passing aicraft is then very close and as a result fails to do so

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1 hour ago, FeelThere_Vic said:

Dear Folks,

We had many discussion about the taxi speed. Officially it should be 25kts or less but for so many requests for faster ground movement we increased it for Tower! 3D.
For Tower! Simulator 3 we would like to reduce it back to 25kts but we would also like to know what do you think about it?

Thank you

 

Vic

Taxi speed has been a T!3DP pain point since day 1. I don't want to be confrontational but I would disagree that we saw faster ground movement in T!3DP. I spent more hours than I'd like to remember on this topic and the fastest taxi speed was only 19 kts.  So, to be honest, a taxi speed of 25 kts would be a welcomed increase.

But, obviously an increase to 25 kts is only the tip of the iceberg when it comes to taxiing characteristics. I think the predominant opinion for T!3DP was that pretty much everything about taxiing was too slow - including acceleration (initial, after a stop/turn), runway entrance, exiting the runway (coming to a complete stop even on high speed exits) to name a few. But this is not news as this has been discussed for several years now and obviously mentioned in wishlist items. 

So, to simply answer your question, a realistic taxi speed would be welcomed as long as other realistic and improved taxiing characteristics are part of the overall picture. 

Thanks, Craig

PS - If you are wanting to slow something down - the pushback/start process would be something I would recommend taking a look at. 

 

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In Tower!3D the maximum taxi speed is 20 kts, that's approximately 33.7562 ft/s. (You or one of the devs might recognise this number.)
image.png.7a5438393e24eb7e5ae36e000a0aa20b.png

This is about right for most aircraft.

However, the taxiing acceleration is rather slow, being around 0.0125G (≈ 0.4 ft/s2) in Tower!3D. The maximum acceleration allowed for passenger comfort is usually stated to be around 0.1G in most whitepapers about taxi flow optimisation, although those same papers show 0.05G (≈1.6 ft/s2) is usual. Expedited runway crossing acceleration would definitely use 0.1G for passenger planes and up to 0.2G for cargo.

Cheers,
Daniel

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If you want realistic taxiing, go to your nearest airport(s) (maybe LAX, maybe SNA, maybe SAN) with a stopwatch and a radio receiver, tune the latter into the ground frequency that handles the taxiway in front of you and meter the time aircraft need to taxi over a distance between two defined points that you can measure via Google Maps, for example.

That being said, not every aircraft having the same taxi speed might be a good idea for realism.

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My 2 cents would be that taxi speed or ground speed first and foremost needs to be situation-appropriate; we previously discussed the real Tower3D frustration of final approach aircraft touching down on the runway and decelerating far too quickly. Overall I agree with their sentiment that acceleration is a bit too low and the old turn-in speed from runway to taxiway was (at times) ridiculously fast.

So, perhaps a focus on both the aircraft situation (location and destination) and also transitions from one taxi "state" to another, i.e., Runway to taxiway at 90 degree angle, acceleration from holding at a runway to cross and clear said runway, etc.  Pushback should be slower than the old game and stick to the taxi tarmac lines to avoid collisions with other parked aircraft. I seriously doubt that aircraft IRL would be doing 20+ kts close to the gate areas, more like half that.

I suppose a good question for you Vic is does the new game have or support assigning a speed to a specific segment of taxiway? This might be a way to elicit a more appropriate plane behavior instead of a blanket 20kt taxi speed everywhere. I can appreciate it would mean more work, maybe there is another better way to achieve the same result? 

As a slight aside, part of what I mentioned in old conversations about how not assigning taxi exits, gates, etc. early enough has a negative domino effect. If the Controller can give runway exit instructions early enough then the game can appropriately slow down the landing aircraft (provided the exit is not too early for the aircraft to do it) to make a proper exit at an acceptable speed. I am no expert on when IRL the controller gives taxi and gate commands to aircraft, but given that in Tower3D we as the player have to do it all ourselves, it would make sense to ease up on any tight timeline to convey instructions.

For myself, nothing ruins the controller experience like commands unacknowledged and aircraft needing to be deleted.

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Quote

If you are wanting to slow something down - the pushback/start process would be something I would recommend taking a look at.

It's done already.
 

Quote

Long straights - 30kt
Straights with objects - 20kt
Turns (dry conditions) - 10kt

Thank you!
 

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However, the taxiing acceleration is rather slow, being around 0.0125G (≈ 0.4 ft/s2) in Tower!3D. The maximum acceleration allowed for passenger comfort is usually stated to be around 0.1G in most whitepapers about taxi flow optimisation, although those same papers show 0.05G (≈1.6 ft/s2) is usual. Expedited runway crossing acceleration would definitely use 0.1G for passenger planes and up to 0.2G for cargo.

Awesome, thank you!

 

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 I seriously doubt that aircraft IRL would be doing 20+ kts close to the gate areas, more like half that.

Great idea, it will make the initial release!
 

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As a slight aside, part of what I mentioned in old conversations about how not assigning taxi exits, gates, etc. early enough has a negative domino effect.

Now you can see the assigned gate as soon as the plane contacts you during it's approach.

Thank you everyone

Vic

 

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On 9/26/2022 at 12:38 PM, FeelThere_Vic said:

Now you can see the assigned gate as soon as the plane contacts you during it's approach.

It should not just pop up, but the pilot should tell you this information. And there should be cases in which the pilot does not do this and you have to ask for it. In addition, even if this information is handy, it is not relevant at the first radar contact, but only after landing.
My humble opinion as a non-ATC. Someone with deeper insight may be able to elaborate. In any case, there should be more communication options and variance than in T!3Dpro.

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