Flying TRACK iso HEADING

[sputnik01]

4.1.3 IFR Vectoring instructions, in upper Airspace (above FL245 PBN/RNAV)

For ATC separation, flying a TRACK is for several reasons much superior to flying the legacy HEADING (precision and automatic wind drift correction).

How easy is it on your airliner/GA flight deck (except A320) / for your flight crews to adapt and
· FLY TRACK (three digits), iso FLY HEADING (three digits)?

Thanks for your input.

[Qwark]

I guess it depends if your flying a C172 or Airbus! Flying a defined track in a C172 could be challenging.

[vilas]

If ATC gives you heading you must fly heading and not track because his vectoring caters for drift etc. If there's a cross wind and instruction is to maintain RW hdg after takeoff flying the track may close in onto parallel RW traffic.

[Uplinker]

Airbus FBW heading selector has two modes: One maintains a selected heading, the other maintains a selected track. The track mode automatically adjusts for wind, as detected by the on-board ADIRS.

Very easy on Airbus !

As vilas says though, the assertion quoted by the OP about track versus heading is a bit suspect - I have rarely been asked by ATC to follow a track. Always headings.

[KayPam]

OP is precisely questioning this practise, and wondering why they don't ask to fly tracks.
You can't say that they don't ask to fly tracks because they ask to fly headings, that's a circular argument.

[Uplinker]

OP has just edited his initial post. It isn't clear who is making the Track vs HDG assertion.

It is still not stated what document this is taken from and what authority they have. It could be the OPs own notes ?!

[tolip1]

It doesn't matter, it's an interesting discussion point.

All IFR aircraft need to be able to follow a track, to follow defined arrivals and approaches. Why not get vectored that way too?

[Vessbot]

The ability to follow a VOR radial or localizer, does not give the ability to fly an arbitrary track from an arbitrary point.

[rudestuff]

Very easy in a Boeing. P/P360 would give you a pink string to follow north. But as mentioned above, no one's likely to ask you to do that.

[Equivocal]

I've been out of operational controlling for many years but back in my day I sometimes put an aircraft on a track, usually DCT to a specific point, but sometimes also to fly an offset to that track for separation purposes. From the controller perspective I would suggest (nothing has changed in the intervening years), if it suits the situation, use the technique. As pointed out earlier, not all aircraft are able easily to set up a TRK to a random point so don't use tracks if any of the aircraft are unlikely to be able to do it easily. Never had any problems either if an aircraft requested a particular track and I vectored other aircraft on headings - that said, I didn't do all this in high density traffic, but if it's that busy I would expect aircraft to be following defined routes and I wouldn't be doing any vectoring.

[NGjockey]

Using the BOEING OPT, what does it mean when the engine failure procedure calls for maintaining a certain number of degrees after departure? Does that number refer to TRACK or HDG?

Here's a specific example:

The engine failure procedure for the departure on runway 07R in HKG is depicted as follows: "At D3,0 SMT LEFT turn to 065. Intercept OUBD R-105 LKC. At D9,5 LKC RIGHT turn to 185."

Are the numbers 065 and 185 HEADINGS or TRACKS? I remember that the procedure design is including a certain amount of omnidirectional wind (30 knots if I am not mistaken), so a certain amount of drift is factored into the design. Common sense would certainly dictate that this is flown as a TRACK to be more accurate, but is there a binding LEGAL definition somewhere?

Much obliged

[ScepticalOptomist]

Procedures are designed with wind components taken into account. You can safely fly heading. Nothing wrong with flying as track either.

[vilas]

If there's large crosswind it will make a difference. If everyone else is drifting downwind an aircraft flying track will get into them. You have to do what ATC wants you to do.

[Capt Fathom]

Vilas. The last couple of posts are about engine out tracks! Not what ATC want you to do!

[aterpster]

It doesn't matter, it's an interesting discussion point.

All IFR aircraft need to be able to follow a track, to follow defined arrivals and approaches. Why not get vectored that way too?
Lots of small airplanes still flying the system that don't have RNAV/GPS.

Having said that, what about getting rid of magnetic headings and courses? That would make management of the system a whole lot easier.

[Denti]

I second that, as far as i know most of the merchant marine has switched to purely true a long time ago.

[TopBunk]

While flying true tracks would probably be the gold standard, surely until every aircraft using the airspace can do that you have to cater for those that can't?

[tolip1]

aterpster

Yes, but these planes/pilots will still be required to, and have the ability to, adjust for wind and fly a track. That was the point I was making.

[aterpster]

Track is alien to controllers. They want heading. My company issued a bulletin on it in 1984 when I moved from the 727 to the 767.

[Vessbot]

Those airplanes are not required to, and do not have the ability to, fly a track.

[vilas]

Vilas. The last couple of posts are about engine out tracks! Not what ATC want you to do!
I know at least a dozen Airlines who's SOP is to tell ATC with Engine out is "maintaining RW heading". Airbus can fly track also but they don't.

[aterpster]

Vessbot

The early 767 I flew defaulted to track. I had to select HDG to fly heading.

[FlightDetent]

NGjockey

EO climb out paths are no IFR procedures, it's operators responsibility. How much of allowance is included depends on the provider to whom it is outsourced, and what the airline would ask for.

IT IS SURVIVAL CRITICAL TO FLY TRACKS AS PRECISELY AS POSSIBLE.

In an obstacle limited environment, usually witnessed by a complex routing of the EFP such as you provided, any extra padding beyond the regulatory minimum width of the protection area will incur a payload restriction. For every single departure. This is a massive economical problem and for long haul liners a real payload range issue. Hence any performance evaluation / guarantee will include the MTOM at common less than-favourite conditions for the given homebase rwy and EFP.

​​​​​​You do not need to ask at all then if the calculated corridor has been widened beyond the minimum. And when you see those numbers it is freaking narrow. IIRC 800 m each side from the theoretical centreline EASA rules, though I heard once the FAA are more reasonable.

[Vessbot]

Vessbot

The early 767 I flew defaulted to track. I had to select HDG to fly heading.

(I was replying to Tolip's post by "these airplanes" but forgot to hit the quote button, then ended up posting shortly after you, so it looks like I was referring to your airplanes, when I wasn't. Oops!)
​​​​​
I don't doubt that many different airplanes have this feature. But it's specifically designed in and provided to the pilots. But what Tolip is saying is that every IFR plane has this ability naturally as a side effect of being able to fly an instrument approach. After all, if it can follow a track defined by a localizer or VOR radial, why can't it follow a track when ATC says "fly track 280" (from your present position?)

You can see that those are two separate things and the former doesn't imply the latter, but Tolip doesn't seem to be seeing it. Not even having RNAV means you can necessarily do this (i.e., routine vectoring). It may or may not be possible with obscure FMS jiu jitsu (like someone posted for the 737) but even that's still a far cry from having it on a heading-type knob on the glareshield (like your 767), which is what would be needed when they're firing off speeds, headings, and altitudes at you every few seconds.
​​

[Max Angle]

If you fly a SRA into Gibraltar nowadays (A320) ATC ask you if you would like to fly tracks or headings, I guess tracks makes everyone's life easier in the shifting winds around the rock. The instructions still come as heading but we have the aircraft in track mode, I have no idea if this is done elsewhere as GIB is the only place I have flown an SRA for years.

[Uplinker]

Yes, good point. At GIB, there are only a few aircraft in the airspace at any one time and well spaced out, so easy for ATC to allow for both tracks and headings I guess.

tolip1 asks about flying tracks in procedures. Simple aircraft without IRS/GPS will not be able to measure and allow for wind, so they cannot automatically follow a track unless it is referenced to a suitable ground based navaid.

[N1EPR]

In the absence of an engine out special procedure provided by the carrier or operator the engine out obstacle clearance criteria are based on flying runway track until clean up altitude. That is why the Boing defaults to track on takeoff.

[ahramin]

I've never been asked to fly an assigned track by ATC but it would make my day if it happened. IRS is over 70 years old. GPS has been widely available for over 30 years. Time enough for procedures to catch up to technology. It's been a long time since I saw an IFR aircraft that didn't have at least a GPS, which means 99.99% of IFR aircraft can fly track. Sadly, this is not normally part of training and many pilots don't understand how to do this in their aircraft even though it's a basic flying skill.

It's ridiculous that in this day and age we are using magnetic heading instead of true track, but some day we'll get there.

[FlightDetent]

ahramin That. DCT-TOs are even great circle tracks.

[Uplinker]

"I've never been asked to fly an assigned track by ATC...............IRS is over 70 years old. GPS has been widely available for over 30 years. Time enough for procedures to catch up to technology. It's been a long time since I saw an IFR aircraft that didn't have at least a GPS, which means 99.99% of IFR aircraft can fly track............
It's ridiculous that in this day and age we are using magnetic heading instead of true track, but some day we'll get there."


Using magnetic must be a PITA in places such as Canada, but isn't it because we still have basic C152s etc. using the same runways as IRS/GPS aircraft? And if all the ADIRUs + GPS failed, (yes, I know....), even an A320 has a normal magnetic field powered compass.

[FlightDetent]

Time elapsed between taking a seat in GPS-equipped SEP and GPS equipped CS-25 jet is 6 years for me, in the favour of the bug-smasher. Midpoint Y2k.

Having said so, that particullar jetliner knew how to fly IRS based tracks since about 1984.

[aterpster]

ahramin That. DCT-TOs are even great circle tracks.
So are TF legs.

[aterpster]

"I

Using magnetic must be a PITA in places such as Canada, but isn't it because we still have basic C152s etc. using the same runways as IRS/GPS aircraft? And if all the ADIRUs + GPS failed, (yes, I know....), even an A320 has a normal magnetic field powered compass.
Far north is true. Remember the 737 crash at CYRB in August, 2011?

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1814x1958/cyrb_2_ee3fbeffb5205d1f4ad5f191794a356036a12569.jpg

[Information Unicorn]

Let’s consider this situation (in an A320)

You’re asked to fly a track of (say) 270deg. Let us assume that parallels your landing runway to the north, effectively a left downwind leg. You are currently in HDG so you push HDG/VS to change to TRK and adjust to 270.

The reason ATC want you flying a track is because there is a strong northerly wind and they want you away from the runway.

The gusty wind gets stronger.

What happens to the a/c?

[pineteam]

It will adjust the heading to maintain the track.

In Beijing Capital, after airbone you are supposed to maintain runway track.. Other airports like Ningbo it’s runway heading.

[BraceBrace]

Very easy in a Boeing. P/P360 would give you a pink string to follow north. But as mentioned above, no one's likely to ask you to do that.

That P/P360 will not work in many Boeings...

[BraceBrace]

While flying true tracks would probably be the gold standard

As a pilot I would say heading is the gold standard, as track is ground based. Relative air movement is what makes us fly, not relative ground movement.The difference is wind. A pilot who is not wind minded lacks a lot of situational awareness as everybody seems to think at the end of the day flying is all about a single straight line. It is a continuous correction based on outside wind values. It is a correction of turn radius when turning final, in the departure,... Knowledge of wind vector is important at every stage of the flight. Liftoff, touchdown, climb, cruise, descent,...

The track based vectors surely aren't going to reduce the number of localiser overshoots on parallel runways I've witnessed... Are we going to blame ATC now for that?

[ahramin]

Uplinker

The real reason is not because there are still a few aircraft around that find it more convenient, but because all aircraft found it more convenient way back when the system was put in place. The technology has moved on, the procedures haven't. That's the way we've always done it may not be a great reason, but it's still the reason. If we make the change, the C152 can equip with a cheap VFR GPS or do the math for the variation. I can't imagine a situation where an A320 would only have compass for direction information while still having flight controls to use that information but in that case they could do the math as well.

The fact is, at some point we are going to make the change. Why not now?

[BraceBrace]

So will ATC be allowed to have us fly groundspeeds then? Makes their life a lot easier when dealing with converging traffic as well... Because we couldn’t measure it "back then” but have the technology now.

We can perfectly fall out of the sky in the airmass providing the perfect requested track at a certain groundspeed... There is a difference between what we use and need to fly, and what we provide to the outside world. It's not because we have to comply with a track request, we have to change what we use on the flightdeck. We can perfectly fly HDG up and provide tracks on many aircraft. Tracks are dynamic influenced by the wind. But our primary point of reference is the air mass because that’s how our wings work.

What about hovering heli's? Their track indication is going to be all over the place close to zero airspeed. What in visual circuits? In track values all turns are going to be 90°. That should to be easy turning... right...?

[ahramin]

BraceBrace you seem to be indicating that flying a given track is difficult. It's really not that hard and all pilots manage it when learning to fly in order to navigate to a given point. Maybe your instructor hasn't covered that yet but don't worry, you'll get there.

When flying a visual circuit yes, turns are 90°. If the runway direction is 180°, downwind track is 360°, base is 90°, and final is 180°. It's very simple and there's no need to worry about air masses.

[Vessbot]

Yes, it is difficult in the situation the thread is about.

Situation 1: (note: this is not the one the thread is about) Flying a Cessna 172 on downwind when there's a crosswind. What to do: Turn the nose slightly into the wind, look at whether you're travelling parallel to the runway, if not then turn slightly to correct, return to "look at..." and repeat as necessary

Situation 2: (note: this is the one the thread is about) Flying a jet under IFR, when ATC says "Speedwood 6969, fly track 280." Procedure: ???

Can you fill in the "???" (never mind a Cessna 172 under IFR getting the same instruction...)

Before you say something like "easy, select track 280!" Remember that many, many jets (including ones with FMS and IRS and GPS and lots of other acronyms) don't have this feature.

[FlightDetent]

Perfect wording - feature is missing. The thread is also about the fact that all these aircraft have that capability.

[BraceBrace]

When flying a visual circuit yes, turns are 90°. If the runway direction is 180°, downwind track is 360°, base is 90°, and final is 180°. It's very simple and there's no need to worry about air masses.

Give any aircraft 25kts tailwind on base, and you will see the effect of the 90° turn thinker. He will overshoot final and end up high on glideslope. Happens on c172, but also on simple LOC intercepts on Boeing 737 unfortunately... because your track line when you start the turn does not give you any clue of the track line leaving the turn. Track lines don’t anticipate future wind, they are a depiction of your actual situation. Even though track changes are 90°, your aircraft will have to turn more, and we fly the required HDG changes. If your APFD used 25° bank standard on vectors... you will overshoot. (777 was crazy in this respect as far as I remember)

Again, we can provide track changes to ATC, no problem. But to maneuver and to know how much, we need HDG on our display. This is how our visual brains are trained when we learn to fly, and this is transfered in IFR through headings.

[ahramin]

Situation 2: (note: this is the one the thread is about) Flying a jet under IFR, when ATC says "Speedwood 6969, fly track 280." Procedure: ???

Can you fill in the "???" (never mind a Cessna 172 under IFR getting the same instruction...)

Before you say something like "easy, select track 280!" Remember that many, many jets (including ones with FMS and IRS and GPS and lots of other acronyms) don't have this feature.
Yes, easiest is to select track 280. If your aircraft doesn't have a track mode, you select HDG and adjust it to track 280. I've never flown a jet that didn't display track somewhere, but in that case I'd just say "unable". Not that hard.

[ScepticalOptomist]

Situation 2: (note: this is the one the thread is about) Flying a jet under IFR, when ATC says "Speedwood 6969, fly track 280." Procedure: ???

Can you fill in the "???" (never mind a Cessna 172 under IFR getting the same instruction...)


I’m not sure why you are making out that this is difficult. In every jet I’ve flown I’ve either had an INS with track read out or a nav display (HDG up or TRK up).

The procedure is the same for both - turn onto a HDG of 280 plus or minus some into-the-wind correction. Check what TRK you are actually flying and then adjust.

[FlightDetent]

Check what TRK you are actually flying and then adjust. I humbly admit flying HDG in the same way - turn towards the mark and don't stop until it's there. Undershoots, overshoots, leaning closer, tapping the needle and cleaning glasses all included.

[sputnik01]

ahramin

It will happen eventually/soon in Maastricht-UAC, EDYY ... (2/3 of the aircraft can fly Track iso HDG by the push of a button).

[jmmoric]

That's gonna be fun.

Now the pilots and controllers have to deal with the "confusion" about what to fly, track or heading, and pilots making the wrong selections both in Maastrict and other sectors/FIR's as well. The good thing about heading, is that everyone uses them, hence noone is in doubt.