ATC: pilot. Turn

lorna_w · Jul 7, 2012

I thought I had this right, but then I read a novel this week that threw it into question for me again, so pilots, please clarify.

When ATC is telling a pilot to turn to a heading of, say, four-zero, that's relative to the map, yes? They might say, "turn right" but if there are heading numbers these refer to degrees on the compass, magnetic heading? (or is it literally on a map, due north is 0, east is 90, etc?) They wouldn't use numbers as relative to the pilot's direction (like, "turn niner-zero degrees relative to your current heading," to indicate a right hand turn), would they?

And the pilot always must repeat any numbers like this, to confirm, correct?

And when would ATC or the pilot use the term "vector" rather than the term "heading"? The pilot says "requesting approach vector," the ATC says...what?

(all this for two little lines in a 75K book. but I want it right.)

DreamWeaver · Jul 7, 2012

I wrote an answer to your question, but then realized I haven't flown in 15 years so some things may have changed

. I'll wait for someone with more recent experience to chime in, and if they don't I'll tell you what my experience has been.

I can say, if they give you a specific heading to turn to, that *is* in reference to north, not to your present heading.

DreamWeaver · Jul 9, 2012

Possible ATC calls:

- Swan 07, turn right to heading 270.
- Swan 07, turn right 45 degrees to heading 270.

In an emergency with directions flying as fast as they can be yelled, one might hear:
- Swan 07, turn right 45 degrees.

You wouldn't hear that last one often, but you might hear it if the controller is trying to avoid a possible collision, or clear traffic for a crippled aircraft trying for an emergency landing. They'll come back and give everyone specific headings once the immediate danger is past.

The word heading in ATC directions always means in relation to north, not in relation to current aircraft travel direction. In the "olden days" it always meant a magnetic heading. However, it wouldn't surprise me if, since the adoption of GPS by everyone down to the smallest puddlejumper, headings might now be given in reference to true north. I don't know that, just guessing.

Yes, readback is always required. Does it always happen? If it doesn't, ATC should request it. Lack of readback or wrong readback is sometimes one of the contributing factors in an accident report.

Aztecsince79 · Jul 13, 2012

Good to check this for even two lines because it's the sort of thing that can trip you up in the eyes of readers. There are a couple of things I know.

First, when ATC says to "turn right, heading 270," they mean west. On the issue brought up by Dreamweaver, when planes are at cruising altitude, they occasionally have to adjust their course to avoid other planes or weather. ATC will say "turn left 10 degrees for traffic." A couple of minutes later they'll tell them to resume their normal course.

Hope this helps.

BTW, if you want some real flavor, try liveatc.net

ATC: pilot. Turn

lorna_w

Hybrid Grump

DreamWeaver

Shakespearean Fool

DreamWeaver

Shakespearean Fool

Aztecsince79