When do I request a transition?

In an effort to help pilots better understand ATC communications, as well as support IFATC, I would like to clear up one situation that is often misunderstood, and that is when to request for a transition through an airspace.

On Infinite Flight, ATC airspace has been established to be from SURFACE TO 5000 FT above the airport and a 5 mile radius. What does that mean? If you are flying outside of the 5 mile radius or above 5000 FT of an airport with Live ATC,
Do not request a transition. This only causes unnecessary clutter on the frequency for the controller when they can spend that time focused on inbound and pattern traffic.

All too often controllers receive transition requests for aircraft that are above 10000 FT and this is completely unnecessary.
Just think of it in a simple way of 5 & 5 (5 mile radius and 5000 ft ceiling).

If you have any questions, feel free to ask on this thread or you can PM me.

Happy and Safe Landings!!

-Skyhawk Heavy


As a pilot, when do you request the transition? When you enter the airspace or before it? Thanks in advance.


Great question Henrik. You want to request the transition before you enter the airspace. You have to get approval to enter the airspace whether its for transition, call inbound, etc.


Ok, so I understand that you have to be at 5,000 feet or below inside of the airspace. What about before you enter? For example, if you’re at 6,000 feet descending to 4,000 feet to fly through KSAN’s airspace. Is it acceptable to request the transition when you’re at 6,000 feet or do you still have to be at 5,000 feet or below to request?


If you know that you are going to be below 5000 at anytime during your descent that would cause you to enter the airspace, then yes, you would request the transition. Keep in mind that the controller will usually issue a transition approval with the “…approved at or above…” command. For example: “N172HVY, transition approved at or above 4000.” With that response you can fly through the airspace as long as you’re altitude is 4000 ft or higher.


Which aircraft are u using

It’s the same regulation for any aircraft.


I know but I like that aircraft

I want to fly that aircraft

Thanks for this information @Mark_Denton!

@Thomas_Thuta It’s a Boeing 777-200ER

It’s the FDS 777-200ER


It’s a Boeing 777-200ER with the FDS livery.

Pulling this back up as a refresher as I had two pilots on the expert server this morning who requested a transition over my airport who were both over 10,000 feet. Appreciate the effort, but transition requests are not needed when flying over 5,000.


Just checking. @Mark_Denton Does the airspace includes all three rings at a class Bravo, all 2 at a class Charlie and obviously one ring at class Delta The reason I ask is there is no 5 mile ring to go by, for example at Bravo Class Airports the airspace rings are about ~ 3nm, 8nm, 12nm. Class Charlie and Delta are even different from that. There’s no consistency. Where do we base this 5nm airspace off of?

I know we have to look up the airports surface height and add 5000 feet and fly above that to be considered out of the airspace, howerver is there some easier way to determine if you are gonna be 5nm from an airport, maybe visually. I have enough to think about as I make my arrival/approach to my destination, to add finding out if I’m 5 miles from and airport or not.

Also, in being more specific, how soon before entering? 1 mile, 5 miles, 1 minute, 10 minutes? Just to be clear and we don’t have transition requests 20 miles away. I’ve had em…

Thanks for your clarification.

Okay, so as Tower Controller and you have a Cessna Citation inbound at 1500, they request transition, what do you do?

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With transitions, you add 2500 from the altitude of your airport (1500 is max pattern alt + 1000 for sufficient spacing between the planes in pattern)

So archerfield (where you were controlling) has an altitude of 67 feet
67 + 2500 is 2567. Now since transition altitudes go in 500 increments, It would be better to clear the transition at 3000 and above.
Hope that makes sense


Thanks, I have read about it before but never fully understood it. That cleared things up

Pretty much, but for IF purposes, treating 67 as sea level is typically sufficient. Of course, it doesn’t kill anyone to have extra separation, so no harm, no foul, but generally seeing that as a 0 MSL field works for IF. I’m sure it’s more stringent in real life, but then again, they could say 2600, but we can’t.