Question for Air traffic controllers
 

The airbus is equipped with a runway track mode which gives lateral guidance on the track the aircraft was flying at mode engagement ( 30ft) during take off.

In other terms , the runway track mode allows the aircraft to maintain the runway centerline .

My question is when instruced by ATC to maintain runway heading after take off , do you expect the pilots to maintain the runway centerline once airborne ? in that case airbus "Runway Track " mode would be very useful as it would allow to maintain the runway axis ?

Or do you expect the pilots just to maintain heading ? in that case a strong crosswind would drift the aircraft from the centerline and could end up totally flying a heading parallel to the runway

Thanks for clarification

If I said "runway heading" I would expect you to fly the documented heading of the runway. If I wanted you to track the centerline I would say "Track extended centerline". We would usually take the wind into account when issuing a heading.

This is quite a common question, and the answer remains the same!

Runway heading is just that, a heading. DO NOT adjust for drift; just fly the heading.

Runway track or straight ahead both mean the extended runway centreline.

This has been discussed ad nauseam on PPRUNe quite recently. I don't know about ICAO, but the UK dumped the 'runway heading' phraseology a while back in favour of 'straight ahead'. Runway heading is still used by some controllers, although technically it shouldn't be.

From CAP493 Glossary Page 10:

Definition of Straight Ahead:

When used in departure clearances means: 'track extended runway centreline'.
When given in Missed Approach Procedures means: 'continue on Final Approach Track'.

Whether or not "runway heading" is still used in the UK is immaterial though, since it is used elsewhere. It's often used in SIDs in North America, for example. Especially with parallel or closely diverging runways, it's important that everyone is on the same page, and that means no correction for drift.

The RAF 'got it right' with this; they always said 'climb on runway track'.

The RAF 'got it right' with this
 

Not a phrase that gets used very often here!

Thanks chevvron.

ps Our drivers airframe get confused with this one as well.

I don't know why more ATC's don't use "Tracks" as opposed heading. The "track" is obviously more accurate, and really helps if your'e affecting a seperation, not having to monitor the ACFT's heading.

Here in SA our Grib Winds (winds at block levels) is not updated regularly, so we donn't have the luxury of depending on, sometimes, outdated information.

In SA RWY heading is used explicitly.

I feel, if an ACFT can fly a Track, use it!

What if only one can fly a track? where's your separation?

Use headings because both aircraft can fly headings and if you're using for separation then they're both going to be subject to the same wind/drift.

Well it really depends on the situation at hand, doesn't it?

If one ACFT is heading/tracking to a specific beacon or waypoint, and another is climbing or decending through his level for instance, then it would be better to use a track for the other ACFT, in my opinion.

Most jet ACFT we work with in SA are able to fly a track anyway.

In my opinion it would be better to have both aircraft on headings. Leaving one aircraft direct to a fix whilst maintaining seperation for a climb-through on another aircraft by using a heading is asking for trouble.

As the question was posed, I assume the aircraft has just departed, hence the en route tracking is irrelevant. In situations like this the instruction is usually for separation, possibly against a go-around most of which have standard actions and usually include a heading to fly. Therefore giving a heading to the departing aircraft will assure the separation. It doesn't matter if there's a strong cross wind both aircraft will be subjected to it. One aircraft on a track and one on a heading doesn't ensure anything.