Altitude Reference: Stratus 2 WAAS or Altimeter?

[dstclair]

I guess I wasn't singled out since my entire flying life has been based around Class B airspace -- started in Houston the moved to the DC area then back to Dallas.

[Jack Tyler]

Since C and B class airspaces are located in the more heavily populated areas throughout the USA, odds are that many of us here have learned in, routinely flown in and/or have been or are based in these airspaces. Consequently, many of us aren't so self-impressed by that reality.

[FastEddieB]

If there’s a single person who has not yet been convinced that an instruction of “fly heading xxx” means something other than to fly heading xxx, I came up with a little thought exercise.

Imagine the Atlanta Departure controller has three planes, right now all at 10,000’, that all are headed to points north. They are a CTLSi , a Cirrus SR22 and an Eclipse Jet, with TAS of 105k, 175k and 290k respectively. He’s also aware of a hellacious westerly wind, about 60k at 9,000’ and increasing with altitude.

Knowing the winds, the controller just wants to “park” them on parallel courses so he can attend to something else for a minute or so. Based on decades of experience and intuition, he assigns the CTLSi a heading of 330º, the Cirrus a heading of 340º and the Eclipse a heading of 350º - different wind correction angles appropriate to their different speeds, and he knows that should insure separation for at least a short time as they fly roughly parallel courses northbound.

His mental image:



He turns his attention to another matter and a few minutes later hears a conflict alert! The CTLSi has somehow managed to fly a track that will have it with 1/4 mile of the Cirrus in the next few seconds! He issues an immediate turn to the CTLSi to avoid the conflict, and now has paperwork to do to explain the conflict.



And the CTLSi is told to “call a number” upon landing. He explains that when given a heading of 330º by the controller, he in fact applied a wind correction angle to fly a track of 330º. On the basis of that, a violation is instituted which eventually results in a 90 day suspension and a 709 ride.

And this was the best possible outcome. The worst? A midair due to a relatively new pilot who was unaware of what an assigned heading meant.

[drseti]

Excellent explanation, Eddie (and I like your artwork too!)

[CharlieTango]

The worst? My mind went to a mid-air where the two BRS chutes wrap around each other.

[Merlinspop]

I don't think it can be explained much more clearly. I can't imagime someone with an intellect greater than a dirty ashtray not getting it now. Why, they would positively have to be an absolute.....

[CTLSi]

....

[CharlieTango]

What's extra fun is watching you guys thrash over a simple concept and a simple way to test your assumptions. Just fly into a Bravo and get a vector...when you attempt comply THEY will decide if you are right. If you are wrong, you will find out right away, they will admonish you over the radio.

In a year flying through one of the busiest Bravo airspaces and often over a major military airfield sitting under a Bravo shelf I have flown the headings assigned, and have never been questioned on just how I got that done....

If you guys wanna fly without wind correction, or you wanna fly just based on a mag compass, have fun...see you at the ramp check.

When transitioning the KLAS Bravo using the VFR transition route it is appropriate to apply your own wind correction.

When you're cleared or instructed to fly a heading and you track it instead of flying it you put others at risk and provide false wind feedback to the controller.

[CTLSi]

......

[VL Roberts]

Retired ATC here. If you are assigned a heading, you fly the heading. I wouldn't put too much stock in what a controller might say in a casual conversation.

You could get yourself into trouble. For example, say you were instructed to fly heading 270 and you cranked in 20 degrees of wind correction and flew 290. If a loss of required separation occurred and the controller asked what your heading was and you replied "290", you just earned a Pilot Deviation.

[SportPilot]

.......

[drseti]

Pilots, now that everyone (including me) has had his or her say, several times, I suggest we move on to other items.

[CTLSi]

......

[SportPilot]

.......

[Merlinspop]

Retired ATC here. If you are assigned a heading, you fly the heading. I wouldn't put too much stock in what a controller might say in a casual conversation.

You could get yourself into trouble. For example, say you were instructed to fly heading 270 and you cranked in 20 degrees of wind correction and flew 290. If a loss of required separation occurred and the controller asked what your heading was and you replied "290", you just earned a Pilot Deviation.

The debate is not over the heading assigned. The debate is over HOW to fly and maintain the heading assigned. If there is cross wind at the altitude being flown the 'ground track' will be different than the magnetic heading.

Guys that do not have glass and/or GPS may not have a way to readily fly a ground track to make sure the plane flys along the heading assigned.

And I am willing to bet that a lot of guys are not correcting for the wind. As was noted in the ATC conversation above. the controller admits that when pilots deviate from the headings assigned, they call and give them corrections.

I am willing to bet that nearly no one is correcting for the wind when told to fly a heading. That would be because they're not supposed to when given a heading to fly! If ATC told you to track a certain radial, or if you're trying to stay within a VFR corridor, THEN you are trying to fly a specified line over the ground and yes, you apply wind correction as needed. But if they assign a heading, you fly that heading. If the wind blows you more than they were anticipating, ATC will give you a different heading.