I recorded this ATC audio clip during a recent flight.

I'm not sure but he may be saying,

6CP, cancel lining clearance......(missing)....traffic will be in position.

Can you complete this transcript? And I don't understand what "cancel lining clearance" is...

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    $\begingroup$ Nice question! I think this type of questions are really good to help people understand ATC instructions better in non-standard situations. Can you please keep the recording accessible for the public f̶o̶r̶ ̶a̶ ̶l̶o̶n̶g̶ ̶t̶i̶m̶e̶ / forever? $\endgroup$
    – DeltaLima
    Sep 16 '19 at 8:56
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    $\begingroup$ obligatory "Please hurry with an answer, I am running out of fuel" joke... ;-) $\endgroup$
    – Michael
    Sep 17 '19 at 17:38
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    $\begingroup$ Wow that's horrible. I couldn't make any of it out and I've been listening to ATC for some time. $\endgroup$
    – Joshua
    Sep 18 '19 at 3:31
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    $\begingroup$ You need to ask ATC to repeat. Otherwise you might not have the opportunity to find out later. Especially if you are approach. $\endgroup$
    – copper.hat
    Sep 18 '19 at 14:09
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    $\begingroup$ @Joshua same. I'm just a casual visitor but I couldn't understand a single word (native English speaker). $\endgroup$
    – Tom W
    Sep 19 '19 at 7:41

I think this is what the controller is saying:

November Six Charlie Papa, cancel landing clearance. I'll have it back for you in a mile or so, traffic will be in position.

We can infer from this that the aircraft he's talking to (shortened callsign N6CP) has previously been cleared to land. But sometime since the controller decided to have another aircraft to line up and wait "in position" on the runway. The controller is now canceling that landing clearance, because he can't clear an aircraft to land while that aircraft is waiting for departure. And he's letting N6CP know that by the time they get 1 mile closer to the runway, he's anticipating that the waiting aircraft will get cleared for takeoff and N6CP will be cleared to land (again).

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    $\begingroup$ Thanks a lot! As you mentioned, I had landing clearance and I've got the instruction from the ATC while I approaching to land. I can understand now! $\endgroup$
    – gusdyd88
    Sep 16 '19 at 5:38
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    $\begingroup$ @gusdyd88 -- if those instructions were addressed to you, you should have asked ATC to repeat them. $\endgroup$ Sep 16 '19 at 14:59
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    $\begingroup$ The “in a mile or so” surprises me, not being a pilot myself. Is the plane moving slow, about the speed of my car down the highway? Or did he take a little under 5s to cancel a landing clearance only to plan on reinstating it in <30s? It seems like after gusdyd88 asked for clarification ATC would have just responded “I canceled your landing clearance but by now you are re-cleared to land.” Is ATC “just following the rules?” Or maybe “just in case that plane doesn’t move and has a sudden power loss where it stands I don’t want to have to more hastily cancel a landing later” or so? $\endgroup$
    – CR Drost
    Sep 18 '19 at 14:55
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    $\begingroup$ @CRDrost Yes, both, it's rules and practicality. It's probably a pretty severe violation to be "cleared" to land when there is a known obstruction (like another plane stopped) on the runway. Controller in BIG trouble if something happens. The subtext is also "a command to abort could happen, be ready" but also "continue your approach at your discretion". $\endgroup$
    – Jeff Y
    Sep 18 '19 at 18:37
  • $\begingroup$ Ah, that makes a lot of sense. Thanks! $\endgroup$
    – CR Drost
    Sep 18 '19 at 19:46

Anytime communication is addressed to you, you need to understand all of it.

Correct is to either

  • ask him to repeat, or
  • read back the part you understood, if you think the rest is unimportant.

Leaving a communications gap creates a hazard. Nobody minds repeating because they know how scary miscommunication is.


"Roger, landing clearence canceled, did not copy the rest, 6CP"

"6 charley papa, turn right heading 220, expedite!"

  • $\begingroup$ Very true, but was the communication addressed to the OP or did they just hear it on the frequency? A canceled clearance requires a read back, and the questioner doesn't seem to have been in a position to do that. $\endgroup$ Sep 17 '19 at 12:13
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    $\begingroup$ @DaveGremlin From a comment that existed prior to this answer: " I had landing clearance and I've got the instruction from the ATC while I approaching to land." It seems like that is indeed the case, from the quote at least. $\endgroup$
    – Baldrickk
    Sep 17 '19 at 14:19
  • $\begingroup$ @Baldrickk - I stand corrected. $\endgroup$ Sep 17 '19 at 14:53
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    $\begingroup$ How does this answer the question? I am rather new on this site so I was curious if answers like this are permitted; I also didn't want to open a meta post just for it, so I ask here in comments. Because to me the question is "What did the controller say" and not "When I don't understand something in ATC that is addressed to me, what do I do?". $\endgroup$ Sep 19 '19 at 6:52
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    $\begingroup$ @geisterfurz007 happens all the time where askers open with one thing, then in comments it emerges they are talking about something else entirely. Often questions are less about "what they literally asked" and more about "what they need to know". See also XY Problem, Frame Challenge, etc. Often we don't elaborately disclaim those, but some of us bristle at California Warning Label culture. Speaking of culture, the instant I read your comment I figured your main haunt is StackOverflow. People are very salty there. They're much nicer here. $\endgroup$ Sep 19 '19 at 15:42

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