Aviation In Canada

Tuesday, July 05, 2005

Phraseology

As I've said before, I believe communication is an art, and an important one at that. Afterall, as an ATC, all you have is communication when you figure out what should be done. If you can't tell someone what you need them to do, where does that leave you? Today's post will have one from the opposite side of things from where I normally post -- this will be a gripe about something overheard from my end of the radio (though it wasn't me who said it).

In this particular situation, the controller spoke with an aircraft who departed Moncton, NB (CYQM), Runway 11, and was flight planned to Houlton, ME (HUL), and onward, as many of our departures do. The controller, wishing to turn him left and vector him around some inbound traffic before letting him go on course, said the following: "... radar identified, vectors for the on course, turn left heading three two zero, maintain flight level two eight zero."

Shortly after this transmission, I was sitting down to relieve this controller in our normal rotation of breaks. During the relief briefing, where the controller being relieved is supposed to detail to the relieving controller the necessary things (what each airplane is doing, the status of equipment at the sector and at the relevant airports, etc), I observed the aircraft in question turning past a track of 320°, to roughly a 290° track. Wind drift is possible, but 30° worth in unusual for a jet. I asked him to verify his heading, and he said it was 295°, which was the heading for HUL VOR. My initial reaction was to turn him back to the right to the assigned heading of 320, then think about it until he passed his traffic.

When I found out what the previous controller had said, it hit me why the airplane had taken the turn further to the left than we were expecting. I confirmed it with the pilot, when I had a second. He said, "We were given, heading 320 for vectors for the on course, but we were able to go on course right away so we turned direct to Houlton." Of course he did. Personally, I think it's a little bit of a stretch, but I can see the interpretation.

I have heard others use this phrase occasionally (certain controllers, anyway), and I have always thought it was inappropriate, since it's vague. Is he actually cleared on course or not? If his flight plan is an airway, that's one thing, but if his flight plan, such as this case, includes "CYQM > HUL J509", you can see where he might interpret this instruction that way. Certainly in this case the controller should have said, "vectors for traffic," instead of what he said, since that was the actual purpose of the vector. The chances of the pilot making an on course turn when told he was being vectored around traffic would be so close to zero as makes no odds.

Clear and concise communications. Using standard phraseology where practical. All the various items stated in our training. They're there for a reason. And there's no teacher like experience. I doubt that controller will use that phrase again.