RWY Heading

[areyoubitter]

I got a clearance the other day out of Zurich "after departure maintain rwy heading, climb altitude 400 ft". Would a controller expect the aircraft to maintain the rwy track, or would they be expecting it to drift with any cross-wind?

Is there a difference between fly runway heading and maintain runway heading?

[Blockla]

Not again.... search function reveals http://www.pprune.org/atc-issues/396951-question-air-traffic-controllers.html

Lock the plane on the runway 'heading'. It's all in the words....

Mods can we post something about this as a Sticky?

[Scooby Don't]

Well said Blockla!!! :ok:

A heading is a HEADING. Just the same as when ATC says "turn left, heading 275", you don't apply any correction. If they wanted you to fly runway track, they would have said so!

As for the difference between "fly" and "maintain", there isn't any though in the UK the word "continue" would be used in place of "maintain".

[criss]

And it should have been used in Zurich too.

[areyoubitter]

Thanks for the link. To me it seems strange to ask aircraft to fly runway heading. As I am sure you are aware drift is a function of true airspeed, and therefore aircraft on the same heading at departure will track differently if they fly different speeds. At Zurich, as at many International airports, the noise monitoring equipment lies along the SID. By flying a heading we invariably trigger a noise violation. Flying the runway track would more often than not prevent this happening.

[Scooby Don't]

areyoubitter - believe me, we DO know all that! We also know that with certain aircraft, it can be easier to fly a track than a heading thanks to the way the FMS is set up. The fact remains, unless there are wildly differing aircraft types involved, drift will have a similar effect on everyone and it keeps everyone on the same page to use headings. It is pretty likely that the next instruction after "fly runway heading" will also be a heading, with luck towards your first en-route fix.

Have a look at some North American SIDs and you'll see lots of extremely simple ones, along the lines of "climb on runway heading to x,000 ft". One of the benefits of such simplicity is that everyone with an IFR flight plan can use the SID, whether in a 1960s Cessna single or a brand new A380.