I was listening to the LiveATC Phoenix North Tower feed as he was clearing aircraft to land. He said something like "Southwest fifteen sixty five, Phoenix Tower, (aircraft type), X miles in trail, runway 25R, cleared to land".

What does the "(aircraft type) X miles in trail" portion mean?

Is the controller pointing out the aircraft behind the aircraft that is being given the landing clearance? If yes, why would the aircraft in front care?

  • $\begingroup$ how clearly did you hear it? Its possible they said Southwest 1565T 25 miles inbound runway 25R cleared to land $\endgroup$
    – Dave
    Jan 30, 2019 at 2:07
  • $\begingroup$ 100%. He didn't do this once. He used the same phraseology more than 10 times with succeeding arrivals. $\endgroup$
    – slantalpha
    Jan 30, 2019 at 2:14
  • $\begingroup$ I still think something is being misheard here. If the OP hears this on PHX tower again, I'd be curious of the time so I can listen myself and provide the most correct answer... $\endgroup$ Apr 2, 2019 at 5:47

2 Answers 2


The controller's telling Southwest 1565 it's cleared to land (otherwise they would use the other aircraft's identification), and by the way there is an airplane of a certain type coming up behind and to take that into consideration in the event that Southwest 1565 was thinking of spending too much time on the runway after landing instead of promptly getting out of the way.

That kind of comment added to the landing clearance suggests that the airplane behind is a little closer than usual, or is going significantly faster, or it's just really busy with airplanes spaced at minimum separation, and Southwest should expedite clearing the runway.

  • 3
    $\begingroup$ This is standard phraseology, and is in the pilot controller glossary. It may also be expressed in "minutes in trail". $\endgroup$
    – Ron Beyer
    Jan 30, 2019 at 4:30
  • $\begingroup$ In light of the new answer that is in direct contradiction to yours, do you have some references to support your claim? $\endgroup$
    – FreeMan
    Apr 1, 2019 at 11:44

I highly doubt you heard the controller correctly, or understood what he was actually saying. Sometimes, the words are spoken quickly and to a novice, is illegible. Also, LiveATC radios are volunteer hosted and not the same as what controllers and pilots actually hear.

I suspect the controller was issuing the traffic AHEAD of the landing traffic. Typically tower controllers issue the traffic AHEAD in the sequence, not behind. I highly doubt a controller would expect a pilot to "figure out" that the mileage call for someone behind him meant he needed to expedite off the runway. Rather, it would include some "slang" language, "expect no delay off the runway, traffic is close behind." If it was being issued multiple times and you heard it repeatedly, you likely heard him letting the trailing aircraft how far behind the traffic ahead of them they were. Lastly, the controller may have been omitting (or you weren't hearing) a key word in the clearance that changed the context. I highly doubt the controller was issuing the trailing traffic to the leading traffic 10+ times in a row.

  • $\begingroup$ Welcome to Aviation! While your argument sounds reasonable, it is in direct conflict with the (current) other answer indicating that this is standard phraseology. Do you have any references to back up your claim? (Granted, there are no references to back the other claim, either.) $\endgroup$
    – FreeMan
    Apr 1, 2019 at 11:44
  • $\begingroup$ I don't have a reference because it's purely a technique used by air traffic controllers, neither is required beyond the "Standard phraseology" of issuing traffic (as cited a little out of context) in the above answer.I suspect any "reference" provided to the contrary will be out of context. If we could hear the actual tapes (OP could provide the date/time they were listening) we could "hear the evidence" for ourselves, as I believe the OP misheard the controller. $\endgroup$ Apr 1, 2019 at 15:33
  • $\begingroup$ It might be possible the controller was advising in case of a wake turbulence encounter. I once sat the jumpseat of a CRJ2. We were getting bumped around a bit on final and the captain asked who we were following... a B738, four miles in trail. Good to know I suppose. If the controller was doing this for every arrival that seems like extraneous phraseology though—I would expect it to be issued for a large behind a heavy, or a small behind a large, but not every single inbound. $\endgroup$
    – randomhead
    Feb 17, 2021 at 1:45
  • $\begingroup$ at some of the more airline-based towers it seems to be a technique thing, do it for everybody and not worry about it or think about who you issued it for vs who you didn't. It certainly could've been, but controllers are blissfully unaware of the affects of wake turbulence beyond a lesson in a computer lesson every couple years when someone screws it up. Good food for thought though. $\endgroup$ Feb 18, 2021 at 0:11

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