Permission to follow the flight plan?

[Joe Connolly]

So, I was out of LAX on DOTSS2 which takes you west a ways then left turn to come back around east. I got barked at by ATC for making that turn- I didn't debate over the comm but I was flying a procedure, was I supposed to get permission to turn?

 

Joe Connolly

KSTL

[Torben Andersen]

Sounds strange to me. Were you cleared for the SID by atc or did he issue vectors on the departure? And were you at the prescribed altitudes? I presume you followed the appropiate route according to which  rwy you departed from.

[Tobias Dammers]

9 hours ago, Joe Connolly said:

So, I was out of LAX on DOTSS2 which takes you west a ways then left turn to come back around east. I got barked at by ATC for making that turn- I didn't debate over the comm but I was flying a procedure, was I supposed to get permission to turn?

It all hinges on what you were cleared for. As a general rule, fly the clearance, not the plan.

If your IFR clearance says something like "ABC123, you are cleared to destination KABC via the DOTSS2 departure, then as filed, initial climb 5000 feet, expect flight level 240 after 10 minutes, squawk 1234", then they want you to fly the SID. If however it says something like "ABC123, you are cleared to destination KABC, after departure maintain runway heading, climb 5000 feet, expect flight level 240 after 10 minutes, squawk 1234", then you are not cleared to fly the departure as published, but expected to maintain runway heading until further notice. I may have gotten the clearance phraseology mildly wrong, as I don't fly in the US a lot, but the gist is that unless you were explicitly cleared for a procedure, you can't just fly it.

[Andreas Fuchs]

Maybe he was cleared for the mentioned SID, but when he received his actual takeoff clearance he was told to "maintain runway heading"? Happens! Could be confusing.

[Koen Meier]

there are some LAX departures that require you to maintain a certain heading but the DOTTS2 is an RNAV departure. it can happen that you get a maintain runway heading however on an rnav departure it is not that likely.

[Alex Noble]

I seem to remember that the American phraselogy now for takeoff on an RNAV SID is something along the lines of "callsign, RNAV to whereever, runway x, cleared to takeoff" for this reason, although no idea how widespread this is, or if this is only used is some circumstances.

[Robert Shearman Jr]

2 hours ago, Koen Meier said:

there are some LAX departures that require you to maintain a certain heading but the DOTTS2 is an RNAV departure. it can happen that you get a maintain runway heading however on an rnav departure it is not that likely.

Whether or not it's an RNAV departure isn't the issue. Example: at KIAD the JCOBY and the RNLDI are both RNAV departures, but the JCOBY prescribes a heading to fly then to await radar vectors, while the RNLDI is completely pilot-nav. 

The DOTTS is also pilot-nav so here's what happened.  Either:

a) the pilot filed the DOTTS but was cleared on some other procedure and didn't realize it;

b) the pilot filed and was cleared on the DOTTS but was given a heading to maintain with his takeoff clearance and didn't realize it;

c) the controller forgot that the DOTTS is pilot-nav and erroneously expected the pilot to be awaiting vectors.  Hey, controllers make mistakes too! 

Edited March 28, 2021 at 07:27 PM by Robert Shearman Jr

[Joe Connolly]

Well thanks for all the replies. I an very inexperienced at this point with ATC, and I can imagine with the "jitters" I still have, it wouldn't have been difficult for me to miss the three little words "fly runway heading", or even file a different departure that what I put into the fmc. . I'm likely the culprit, and going forward i'll  "fly the clearances" as suggested and listen to what they actually say- rather than what I expect them to say. Good Info, thanks again!

[Joshua Jenkins]

2 hours ago, Joe Connolly said:

listen to what they actually say- rather than what I expect them to say.

Yeah that's a big one. Confirmation bias can (and in real life, has been) deadly in aviation.

Edited March 29, 2021 at 03:24 AM by Josh Jenk

[Andreas Fuchs]

20 hours ago, Joe Connolly said:

Well thanks for all the replies. I an very inexperienced at this point with ATC, and I can imagine with the "jitters" I still have, it wouldn't have been difficult for me to miss the three little words "fly runway heading", or even file a different departure that what I put into the fmc. . I'm likely the culprit, and going forward i'll  "fly the clearances" as suggested and listen to what they actually say- rather than what I expect them to say. Good Info, thanks again!

That's why it's so, so important to not just write down the clearance before reading it back, but then to also review your FMS/GPS waypoint data to make sure that it matches the assigned SID/departure instructions.

Edited March 29, 2021 at 09:45 PM by Andreas Fuchs

[Robert Shearman Jr]

19 hours ago, Joe Connolly said:

Well thanks for all the replies. I an very inexperienced at this point with ATC, and I can imagine with the "jitters" I still have, it wouldn't have been difficult for me to miss the three little words "fly runway heading", or even file a different departure that what I put into the fmc. . I'm likely the culprit, and going forward i'll  "fly the clearances" as suggested and listen to what they actually say- rather than what I expect them to say. Good Info, thanks again!

On VATSIM, without the benefit of dozens or hundreds of hours of formal flight training, we learn a lot by trial and error.  It's okay!  Coming here and asking questions about what happened and how you can improve for future is the exact correct thing to do.  Bravo!