Line up in sequence/behind

[sailor]

To settle a small flightdeck discussion would any knowledgable ATC whizz confirm that a clearance to "Line up in sequence ( or behind) the departing XYZ" clears the so-cleared aircraft to cross the holding-point line and progress toward the runway. Obviously this allows expeditious traffic departures particularly when a crossing pair of runways is in use for landings and takeoffs as in BCN.
Thanks in anticipation for definitive solution!

[DJ Mixmaster]

I have wondered about the same thing...I think I know the answer after talking to an ATCO. Yes, you are cleared to cross the holding-point line, but not until the departing aircraft has completed the take-off. But this is obviously not very convenient. And the reason to why the ATC gives such a clearance, is that it releaves them from the responsibility to wait until the departing aircraft has completed the take off.
You might think..."But I've got my clearance, why can't I cross that line?"
Think of it this way. You get the clearance: "Behind traffic on final, line-up and wait behind."
Same thing, you have the clearance, but you have to wait.

I must add: I am not a whizz and if I am totally wrong,
please correct me.

Cheers!:ok:

[alf5071h]

Extract from UKCAA doc CAP 413 Radiotelephony Manual.

Conditional phrases will not be used for movements affecting the active runway(s), except when the aircraft or vehicles concerned are seen by the controller and pilot.
Conditional clearances are to relate to one movement only and, in the case of landing traffic, this must be the first aircraft on approach. A conditional instruction shall be given as follows:
a) callsign;
b) the condition;
c) identification of subject of the condition;
d) the instruction.
e.g. “Fastair 345 after the landing DC9, line up”

Thus I interpret this as not to cross the line until the landing traffic has passed you. The other argument for this is that if you do move forward you may infringe the obstacle clearance zone for landing traffic.

[NW1]

I don't know the global rule (or a reference to it), but locally at LHR it is part of their "minumum runway occupancy time" drive that a conditional line-up clearance after 1, or very often several, departures does authorise you to pass the holding point line and get snuck up into the "neck" - actually you are requested to so, so that you are lined-up and ready to roll immediately you get takeoff clearance.

And as for the "single movement" comment, it is a periodic cause of confusion at LHR where you might have a conditional line-up clearance 5th or 6th in sequence from N and S of the centreline.

[Musket90]

Runway holding points serving instrument runways are positioned where they are to ensure aircraft or vehicles at the holding point 1) do not infringe obstacle surfaces for landing aircraft 2) do not infringe ILS sensitive areas during low vis procedures.

In the case of conditional line up clearances behind a previous departure then as long as visibility is good and there is no landing traffic then I see no reason for the conditional line up aircraft not to cross the holding point. It's up to the pilot to judge what is a safe distance between the other aircraft ahead. At night when runway guard bars are in use then it helps if controllers can ensure the red bar is suppressed when giving conditional line ups behind a previous departure so as to minimise runway occupancy time.

Reducing aircraft occupancy time on runways means less delay and more capacity and as long as it is done safely then everyone benefits

[bookworm]

I would strongly recommend that anyone issuing or receiving conditional line-up clearances read the accident report for G-SSWN (http://www.bea-fr.org/docspa/2000/g-wn000525a/htm/g-wn000525a.html), the Shorts 330 involved in a fatal accident at Paris de Gaulle.

It does not necessarily make a case for avoiding such clearances, but it does show how spectacularly things can go wrong if someone loses the plot.

The recommendations are worth considering for anyone involved in designing procedures for conditional line up, in particular that:

* the instruction include the holding point that the aircraft should cross to line up

* the instruction to line up behind another aircraft uniquely identify the preceding aircraft.

In other words "line up number two" is asking for trouble.

[vintage ATCO]

It does not necessarily make a case for avoiding such clearances, but it does show how spectacularly things can go wrong if someone loses the plot.

More so, it made the point about operating in two languages. I don't think the crew of the Shorts could have had the plot in the first place because of that.

I use conditional clearances all the time, within the rules in MATS Pt1. You have to, to make the traffic move. As regards creeping over the line, we have one hold which is back a bit further because of the taxiway geometry and its uphill. I don't mind a bit of 'creep' against another departure but not against a landing and I will say something if I see the departure moving. Most crews play it this way.


VA

[spekesoftly]

Conditional line up after a landing aircraft - you can cross the holding point as soon as the lander has past you.

Conditional line up after another departure - you can cross the holding point as soon as there is sufficient space.

In either case, pilots are expected to exercise their own judgement wrt to jet blast or prop/rotor wash. (as you would when following another aircraft on the taxiway).

Stick strictly to correct phraseology, as already mentioned.

If the red stop bar is still illuminated, or any other doubt - query it before moving.

[Scott Voigt]

Actually, you can keep the traffic moving just fine without conditional clearances, we do it all the time. I've seen it used well and have no problem with conditional clearances though.

regards

Scott

[Miserlou]

I have not noticed mentioned in this thread the requirement to use the word 'behind' twice in both the clearnace and the readback.

"Callsign, BEHIND the landing xxx, now departing xxx, line up runway 37 BEHIND and wait."

My understanding is that it is open for the crew to decide if they consider it safe with regard to jet blast when to move in to the runway.
That said it would be dangerous to cross the line before a landing aircraft had passed or before a departing aircraft using an earlier hold to had passed. As long as you remain behind the mentioned traffic.
Rather err on the side of caution though.

[PPRuNe Radar]

"Callsign, BEHIND the landing xxx, now departing xxx, line up runway 37 BEHIND and wait."

Runway 37 you say ?? ;)

[Fly Through]

That phraseology is used in the UAE as per ICAO but in the UK it's "After the landing......" and "Behingd the departing....." Just once in each case.

Was told the other day by a pilot that he was turning onto 390!!! ;)

[ATCO Two]

Miserlou,

"I have not noticed mentioned in this thread the requirement to use the word 'behind' twice in both the clearnace and the readback".

"Callsign, BEHIND the landing xxx, now departing xxx, line up runway 37 BEHIND and wait."

Flythrough beat me to it - this is not standard RTF phraseology in the UK (although it is ICAO phraseology).

Actually Flythrough it is "After the landing....", and "After the departing..." in each case. Behind is not used for reasons that I have mentioned before.

Maybe there should be an ATC FAQ section to cover these recurring topics, such as this one and "Descend on the ILS" etc.

[Little One]

Here at the tip of africa we have to use behind twice ( cause management thinks us twice as dumb i think), but only on a landing conditional and we have to also confirm that the trafic at the hold has the landing in sight, bit dumb but very cautious. A conditional line up in sequence to others on the taxiway is basically "line up in sequence/turn" (sequence is the preferred new word that managment wants us to use but the old dogs use turn). We normally hold traffic at the CAT II hold and TWR will take them to the CAT I hold in departure sequence but if all are already on the same taxiway or already sequenced by GMC then "line up in sequence" is used meaning that they can cross the CAT II hold to the CAT I and as the previous starts thier take off roll move on to the runway. Personally I would prefer acft to stay at the CAT I hold till the preceding starts to roll but if you do nudge forward its your windscreen that gets pock marked by any debris that could be thrown up. Also if you don't nudge forward and i Need to cancel a line up clearance its easier if you are still behind the CAT I hold

And we don't have a RWY 37 in africa either