line up after/behind etc.

[funfly]

I know that there has been discussion about the "after the *** line up" and "behind the *** line up". However I have been told that this request is to be removed altogether and the "line up" command will only be given after the event rather than conditional to the event i.e. the decision will not be left to the pilot to decide when a certain aircraft has passed by.
Is this on the cards? it seems sensible to me.

[HEATHROW DIRECTOR]

So a procedure - perfectly safe when used correctly - is to be scrapped? Presumably the airlines have accepted the inevitable reduction in movement rates?

I do not believe that tight single-runway operations will work without conditional clearances.. Be interested to hear something from my ex-colleagues at Gatwick who are real SRO aces.

[chevvron]

Only at certain airfields Bren; all because aces at a certain airfield were using non-standard 'line up in turn'!.

[Spitoon]

Perhaps the problem is exacerbated by the way that the procedure is used (or certainly has been in the past) at some airports like Heathrow.
In the UK the rules say

Conditional clearances shall not be used for movements affecting the active runway except when the aircraft or vehicles concerned can be seen by both controller and pilot or driver. Conditional clearances are to relate to one movement only and, in the case of landing traffic, this must be the first aircraft on approach. However, when a number of aircraft are at a holding point adjacent to a runway then a conditional clearance may be given to an aircraft in respect of another that is ahead in the departure sequence. In both cases no ambiguity must exist as to the identity of the aircraft concerned.

The bit about one movement only can be interpreted widely - some might say abused. The practice of setting up a string of conditional line up clearances -say, a B747 after the A310, a B737 after the A310, a MD80 after the B737, an A319 after the MD80 and an A330 after the A319 satisfies the rule that the condition relates to one movement only - but is it wise? Then consider that often it is not a variety of aircraft types around the holding point but rather a bunch of similar types all with the same livery. This can easily lead to misunderstandings - and has done in the past. There were some rather amusing posters floating around a while back on this subject.

OK, not all of the incidents occurred at Heathrow, but using the procedure - which has inherrent potential hazards - in that way focusses attention on it. And if the procedure is withdrawn it may be a case that everyone loses out because of the actions of a few.

[GT3]

There was a 2 week trial at LHR of one conditional clearance only at any one time at LHR in early Feb. Majority of ATCOs did not like it as it took your focus away from traffic approaching the hold and reduced the ability to effectively plan an order. It also meant two transmissions per a/c rather than one thus increasing r/t loading.

The aircrews made numerous comments on the r/t as they felt out of the picture.

Will be interesting to see the results of this "trial".

[HEATHROW DIRECTOR]

It's very interesting to see how things work nowadays. I only ever used conditional clearances relating to one other aircraft, although I would have half a dozen issued with line up clearances. The clearances would take the form, for example: "After the BA 747 on your left departs, line up..." "After the British Midland A321 on your right departs....", etc. In each case there could be no possible confusion. I believe this was by the rules as each aircraft only had a clearance relating to one other movement - he simply watched that one and that was it. Of course, this only relates to one runway being used for departures. Under SRO it would not. Would it be permissable today?
Can't say I'm impressed with "line up in turn" - if something goes wrong, who hangs?

[yonash]

In Warsaw, we're pushed to optimise departure sequence, so we started using conditional clearances more and more. There were almost no concerns about after/behind, but while we urge pilots to take most suitable distances for departure, the question become important again.

We use, what is agreed by our CAA, behind. It doesn't make any questions or problems (the only one we have is with BA pilots - they're always not ready while reaching the threshold, asking for 2-3/couple minutes until they gets final figures/cabin ready - do you have such the experience with BA? ).
What we also use is "line-up in sequence", but it requires assigning the sequence number to the pilot. It, of course, is worth using with the single-entry rwy, otherwise it makes some troubles.

[Turn It Off]

Our use of conditionals on the runway is being taken away. Apparantly it is safer

[yonash]

I think it mostly depends on procedures.
A masterpiece, in my opinion, was at Gatwick once. I've joined a crew for cockpit flight, which we're allowed to, and was listening to the twr and organisation. Instead of nervous, as it would probably be in WAW, athmosphere, it seemed to be relaxing, fully according scenario, job, which i really enjoyed.
On, AFAIR, 8nm spacing there were 2 departures, the line-up process was almost immediate, after the landing actf passed the holding point. That's something nice.
Most of the cases with line-up behind, in my opinion, come from the pilots' confusion. The traffic info given together with complete silence on twr frequency shows, how good coordination was between GND and TWR (different holding points and frequency monitoring instead of immediate contact). For atc from such an expanding airport, as Warsaw is, when traffic grows rapidly over months, and all the changes are implemented continuously, this kind of order is enjoyable.
Would like to go to Gatwick twr once and see it from behind the scene
So, back to the subject. I don't want to loose opportunity to issue "behind", as it really helps. I'd rather try to keep up proper level of pilot's response and understanding of the situation.