Heading vs. track

[Guest]

Yesterday, I was chugging happily along at cruise altitude in my Cessna Cardinal with a 57 kts cross wind from the west. Suddenly, I was instructed to change heading to 005 because of traffic. As it were, my track was 020 in accordance with the plan, but because of the wind the plane was pointing at 003 or thereabouts.I thought: "Surely, he wouldn't want me to turn two degrees right for traffic, so he must be referring to my track across the ground." I therefore turned left until I was tracking 005. (My Cardinal has a nice GPS SL320 that makes this easy to confirm.)After a brief moment of peace, he yelled at me again, asking me why I hadn't initiated the change of heading yet, or something to that effect. I then pointed the aircraft towards 005, which didn't make much sense at all but seemed to make him happy.At the evaluation, I was slated for not following heading instructions promptly.This experience made me think: are all heading instructions in RC3 referring to magnetic heading rather than track? If they are, are they adjusted for wind? If not, isn't there a real danger that they may lead you astray, particularly in small, slow aircraft in windy conditions?

[jd 57]

i believe it is magnetic. i don't believe they are adjusted for wind.

[Guest]

So, I guess this means that RC doesn't know/care about the wind when giving me vectors, and if I compensate myself, I risk getting yelled at for not pointing my aircraft as directed by the ATC. Right?I can see why this approach would be easier to implement, but maybe in a future release the ATC could either take wind into consideration before issuing vectors or keep an eye on your track when evaluating your actions.For now, I'll have to loosen the heading tolerance before taking my Cardinal up on a windy day :-)

[jd 57]

the heading watchdog routine watches your course not your heading. so as long as your course is 55, i don't care what the plane's heading is.

[Guest]

i don't care what the plane's heading is. Interesting. So, if it doesn't know what the aircraft's heading is to start with, how does RC3 select a heading to fly when giving vectors for traffic? This situation (i.e. wanting to turn an aircraft without knowing its heading) occurs frequently in the r/w and one way we get round it is by giving a specific number of degrees to turn - e.g. turn left 20 degrees or turn right 30 degrees and so on - but, if I recall, RC3 issues an actual heading. When the aircraft has a lot of drift on, you can easily get into the situation described above by doing it this way and, in very strong winds, the aircraft can even turn the oppsite way to the one you were expecting.Pete

[Guest]

>the heading watchdog routine watches your course not your >heading. so as long as your course is 55, i don't care what >the plane's heading is. This is inconsistent with my findings. As I wrote, when I changed my heading so that my course/track was equal to the direction I was given, I got yelled at. When I pointed my aircraft toward the direction I was given, the ATC was pleased with me, although the result was that I barely deviated from my planned course. This happened twice on that flight.

[Guest]

I think the explanations got flip/flopped here. In v's for xfic, RC watches heading, not course.As to whether just a few degrees of turn make sense, it apparetnly makes sense to the controller ;). Normally (at work) turns are at least 10^, often far more but it's not unusual to turn 5^ or less.I'm watching course. Don't worry about it! I see what you're doing, I see what your xfic's doing. My problem. A small turn's in the (I call it) insurance policy category ;), giving me just a "tad" more.

[Guest]

Doug,Thanks for clarifying that. Now I know that if the ATC vectors me for traffic, I just look at my compass and let him worry about the rest :-)But what about other vectors, then? I hope at least those for runways are course directives, because with winds like the one I had the other day, there's a real changew that I'd miss the airport completely if I just pointed the aircraft in the direction he says.

[Guest]

Simple as this... you're right. Apch is looking at heading and should be looking at course. A design flaw, my fault. I've never had a wind so strong that things didn't work out, but some have been interesting :).

[Guest Scott Campbell]

Doug,On the other hand, I always look forward to switching to APC and just flying a heading. It's the first time in a flight I can stop stressing over wind-correction angle and just do what I'm told (and we all know I'm good at that :-lol).I have this: "When I make it to Approach, I'm free" thingy. ;-)

[Guest]

>Apch is looking at heading and should be looking at course.Forgive me for being a nuisance, but I want to be 100% sure I get it right.Are you saying that whenever Approach/Departure provide me with a direction to fly, it's a course, but when they check to see if I'm following directives, they're reading my heading?Is it only vectors for traffic that are actually heading directives? I'm not complaining or anything, it's just important to know the rules of the game.

[Guest Scott Campbell]

Henrik,> Is it only vectors for traffic that are actually heading directives? No. On Departure and Approach, you are told to fly a heading not a course. So when you are vectored for traffic, or are on DEP or APC, fly the heading given you.Center in the only one who expects you to fly the course (heading +/- wind correction angle).

[Guest]

>> Is it only vectors for traffic that are actually >heading directives? >>No. On Departure and Approach, you are told to fly a >heading not a course. So when you are vectored for traffic, >or are on DEP or APC, fly the heading given you. I understand that I must fly a heading as given to me to keep the controller from yelling at me, but if the winds are very strong, I may end up far away from where I want to be. E.g., I may never intercept the localizer if I follow the instructions. Isn't this correct, at least in theory?>Center in the only one who expects you to fly the course >(heading +/- wind correction angle). Except when issuing traffic vectors, if understand correctly.