EHSI Ground Track and ATC vectors, how to reconcile?

[Guest]

On the real world 767, how do pilots implement vectors given to them by ATC in regards to the EHSI? Because the EHSI primarily displays mag ground track with the 'lubber line' and also digitally in the little window, do pilots fly the actual assigned mag heading vector or the resultant ground track of the issued vector from ATC as would normally be displayed on the EHSI? I know the real 767 as well as PIC displays actual mag heading via the white arrow on the EHSI display, but I was also wondering if there is a way to switch the lubber line and digital heading readout on the EHSI to mag heading rather than mag ground track?Is there a way to do this on PIC too? I think I remember reading that there is a way to switch to true heading display but I'm not sure about the ability to switch to mag heading for the primary display.Thanks for any information!

[Guest HPSOV]

If ATC tells you to turn left heading 270, then you do just that!You turn to a heading of 270 vis the use of Heading Select on the MCP.The resultant ground track is irrelevant, as you are flying the heading as requested by ATC.Having the EHSI Map track up is a lot more useful, as this shows your track, ie where your aircraft is actually going, as opposed to just where its heading.As a side note British Airways have their EHSI's heading up, and the track lines bends with the wind. I dont know of any other airlines that operate this way.

[Guest]

Thank you HPSOV. It seems that in PIC767 that the dialed up MCP heading flies a mag ground track rather than mag heading, I've always wondered about this not seeming to be quite right. Does anyone have any further insight into this being the case with PIC?Thank you.

[Guest ilh]

For an MCP setting, PIC flies the magnetic heading, not track. The EHSI map mode will show track straight up, and the heading with a white triangle.Lee Hetherington (KBED)

[Guest]

JonasGrumby,This picture might shed a little light on what you're trying to sort out here (btw, they are exactly right...when ATC tells you to "fly heading 270"...you simply dial 270 into the heading selector on the MCP).http://images.andale.com/f2/109/127/632235...893148_HSI2.jpg(this pic was taken PHX to MSP just southwest of Gallup, NM...nice wind, eh? Don't let the heading bug confuse you...we routinely set it at the aircraft heading, that way when ATC says..."turn left 30 degrees"...it's a simple thing to just do the math off the heading selector, turn the knob and press "HDG SEL") In a no wind (or exact headwind or tailwind) situation, the heading and ground track would be the same...but this never happens (well, almost never happens). So since the aircraft is flying a wind correction angle, the HSI design folks had to decide how to represent that. Have the nose of the airplane at the 12 o'clock position of the HSI, or the intended ground track. I will say, that after flying "steam gauge" aircraft all my life, it took a few minutes to register what this thing is telling you. Just remember, the "sailboat" is the aircraft heading. It would look really strange if the heading were at the 12 o'clock in the HSI, and the ground track was off on some angle....they would've confused pilots all over the world.later,BBall----------------------Capt. William "BBall" BallBoeing 757, Northwest AirlinesSenior Editorwww.frugalsworld.com

[Guest jase439]

That would be rather bizarre, wouldn't it...as the moving map would scroll at a variable angle determined by wind direction and strength. It would be terribly confusing to visually ascertain exactly how the aircraft was tracking at any given time (assuming one chose MAG HDG to be up).This was a good question, though.J

[Guest]

Actually guys, flying with HDG up is quite natural. It's just like flying with an HSI and the Track line is simple to read - you just put the track line on the magenta line and off you go! If you want to route direct to a point, just turn the a/c until the track line is over the point.This way you fly a heading corrected for drift to give you the required Ground Track.As an aside the Max Drift Formula Max Drift Angle = Wind Velocity x 60 / TASdoes work at all altitudes and speeds!Dead Reckoning lives, even on Boeing 737s :-lol :-lolCheersRobbie

[wchafe]

I can assure you that PIC correctly flies the magnetic heading as dialed in on the MCP.Wade

[Guest]

Hi Wade,Nice to hear from you....folks around here been missin' ya.Rob.

[Guest Martin]

>when ATC says..."turn left 30 degrees"Isn't that rather sloppy R/T? Shouldn't ATC always say what heading they actually want you to fly, instead of letting you do some math and perhaps become confused?Martin767 fetishistIt's a lot like life and that's what's appealing

[Guest ielchitz]

Martin,Perfectly legal in the USA (7110.65 5-6-2 "Vectoring Methods").ATC does not necessarily know what your heading is - they might want you to make a series of 30 degree turns for radar identification, their own amusement, or more likely for separation or sequencing.You are probably right that it can lead to some confusion, but it is certainly not sloppy at all.Either way - remembering to reset your MCP heading to match what LNAV is doing, probably is a good idea. I'm not sure if it's proper procedure, but I know last night departing Boston I set my MCP to a heading of 090, so after I reached BOS 4DME I could arm the HDG SEL mode to get the FD to guide me into a nice right turn (in the end they gave me 15R so the whole plan went up in smoke).Then again - I'm just a guy who sits in front of his computer flying a desk and attempts to give some quality separation and vectoring services to a bunch of other desk pilots.Ian Elchitz CYWG

[Guest ilh]

Wade, been busy building us something new?Lee Hetherington (KBED)

[Guest jase439]

Of course, everything works as advertised in PIC ;-) Even old as it is, it's still the best panel for FS out there - maybe not the sexiest, but certainly the most "correct" (apart from the warning annunciators all lighting up at once every now and again ;-)Anyway, this is easily verified by dropping into HDG SEL in a strong crosswind and pointing the aircraft at a waypoint ~40 nm away. You'll find you have to constantly correct to stay on course.JPS. Doesn't the 747 or 777 offer some kind of switch that allows the EHSI (or maybe the HDG SEL knob on the AFDS) to be toggled between TRK and HDG modes? Maybe I'm thinking of TRU vs MAG.

[Guest Martin]

>You are probably right that it can lead to some confusion, >but it is certainly not sloppy at all.OK, thanks for clearing that up. It sounded a bit like another case of the American-sloppy-R/T syndrome. ;-)>Either way - remembering to reset your MCP heading to match >what LNAV is doing, probably is a good idea.It certainly is, since engaging HDG SEL won't make the plane make any sudden turns, and also of course (in my opinion) to give you better awareness of what heading you're flying and what turns the plane is taking under LNAV control etc.>I'm not sure if it's proper procedure, but I know last night >departing Boston I set my MCP to a heading of 090, so after >I reached BOS 4DME I could arm the HDG SEL mode to get the >FD to guide me into a nice right turn (in the end they gave >me 15R so the whole plan went up in smoke). I'm not sure, but I believe that it's normal procedure to set the MCP to the runway heading. But as we (mostly) don't have F/Os in FS, it's sometimes good to set it to another heading if there's an early turn on depature.Martin767 fetishistIt's a lot like life and that's what's appealing

[Guest]

Hi,Actually both heading up and tracking up do exist in MAP mode depending on the airline configuration.e.g. NorthWest use TRK up mode while British Airways use HDG up configuration.Here are a couple of pics which I have copied from PS1.3 screen. They will show you the difference between both configurations and how they will show on the ND bearing in mind that the approach is the same in both shots.mofa