"After the departing.... line up"

[FlyingForFun]

A quick query regarding the phrase "After the departing.... line up".

The scenario is that the departing aircraft in the conditional part of the clearance was ahead of me at the same holding point, and received a clearance to line up. He did so, and is now on the runway, awaiting clearance to take off.

Assume that there is enough space on the runway for me to line up positioned behind the first aircraft. Also assume that I'm happy that there is no safety issue with lining up behind him (e.g. jet-blast or prop-wash as he applies take-off power).

Do you expect me to a) line up now, and position behind the other aircraft, or b) wait until the other aircraft begins his take-off run - which might be a little while if he hasn't received his take-off clearance yet - then line up?

It seems, from watching what others do, that the convention at my current home airport is different to my previous home airport, and I can't find any written reference.

Thanks!

FFF
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[HEATHROW DIRECTOR]

Historical note.. In the UK the phrase used to be "Behind the departing..." Then there was at least one serious incident when an aircraft lined up behind one already on the runway.. and got blown away! The word "After.." is intended to mean "when the one ahead has gone, line up".

[VATCO]

CAP 413:Line up instructions may be issued to more than one aircraft at different points on the same or crossing runways provided that:
a) it is during daylight hours;
b) all aircraft are continuously visible to the aerodrome controller;
c) all aircraft are on the same RTF frequency;
d) pilots are advised of the number of aircraft ahead in the departure sequence, and the position/runway from which these aircraft will depart;
e) the physical characteristics of the runway do not render preceding aircraft in the departure sequence invisible to succeeding aircraft on the same runway.
When line-up will take place at a position other than for a full-length runway departure the intermediate "Holding Point" designator shall be included in the line-up instruction.
Probably either of your scenarios could be correct and acceptable, depends as you say if you are happy with the prop wash etc.
I'm sure this thread will have some interesting debates though.

[stag1]

After the departing means exactly that.If the a/c ahead is not rolling it is not departing,You shouldn't go beyond the holding point until the a/c on the runway rolls.If the runway is long enough to have two a/c lined up then the controller would say line up rwy.... N0 2 to depart etc etc.Thats my understanding.I don't like to see a/c creeping on to the rwy whilst the other a/c has not yet rolled.if the first a/c for whatever reason takes too long and the controller decides to change his/her mind about being able to get the second a/c away ahead of an inbound he or she won't be able to cancel that conditional clearance,as it has already gone beyond the holding point.

[161R]

Whilst VATCO quotes correctly, his answer refers to multiple line-ups ie More than one aircraft lining up at different runway intersections.
Conditional lineups refers to lineups after a landing aircraft or, as in this case, from the same position after a preceding departure - two quite different scenarios, and subject to a different set of rules.
After the departing means exactly that - after he's started to roll. You aren't going to get away any quicker by lining up before he's rolled, as the earliest time you'll be given takeoff is when the preceding is no longer in contact with Terra Firma, so at least 30 or 40 secs after commencement of roll.
But, when I say "Clear for take-off", d'inny hang aboot!:ok:

[BOAC]

See also http://www.pprune.org/forums/showthread.php?t=245787

[Cough]

Quote from our ops manual...

If cleared to line up behind departing, do not wait for the departure to start roll before crossing hold line, start pulling forward as soon as possible.

[161R]

In conclusion then, once the condition has been satisfied i.e.

the preceding departure has either reached a position at which no one else can get past anyway or,

the landing aircraft has passed you,

Please feel free to move forward past the holding point, but, to line up immediately behind a departure that hasn't yet rolled, seems a trifle unnecessary!

[GT3]

You will see tailgaters on the runways at LHR. I wonder if they drive home in the same fashion??

[Scurvy.D.Dog]

agree with 161R
.
.. other thing to consider apart from the time it takes the preceding to roll and become airborne (so no immediate hurry to get in behind them at the commencement of their roll), is the possible micro missiles that might get picked up and imbedded in your machine from the blast from the engines in front being set to 'strangle the cat ol' cock' :ok:

[FlyingForFun]

Thanks for the input, guys.

Is it fair to summarise the above replies as follows: You may cross the holding point once the clearance is issued (although no one will mind if you choose to wait until the aircraft hsa started rolling), but don't actually line up behind the aircraft until it has started rolling?

FFF
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[Dr. Evil]

I would say the "line-up after" should be arranged so that when the previous departing is airborne the following aircraft is aligned with the runway centreline and ready to go to avoid time wasting. The conditional clearance is a tool for ATC to avoid gaps which accumulate delays. But show some airmanship and let the first acft roll some before lining up :ok:

[Reverand Lovejoy]

FFF,

If you were to follow the departing aircraft onto the runway you would not be able to commence your take-off roll immediately and there would be a delay. This delay is going to be similar to the delay at the hold bars, therefor no need to creep IMHO. I would let the person in front start to roll and then take up my position. This saves the nose taking a sandblasting.

How is commercial life treating you? I followed your CPL diary and have now found myself in similar shoes to you with CTC.

Hope all is well
The Reverand :ok:

[Giles Wembley-Hogg]

At my home base, I like to be in a position to enable the controller to use "reduced separation in the vicinity of an aerodrome".

G W-H

[Barnaby the Bear]

At my home base, I like to be in a position to enable the controller to use "reduced separation in the vicinity of an aerodrome".


Eh? What has that go to do with a conditional line up?

The conditional clearance is a tool for ATC to avoid gaps which accumulate delays

Well kind of. I would say more to allow you to move onto other calls. It is therefore more expeditious (if that is what you meant?).

If I give a conditional line up clearence and you pull onto the runway behind an A/C that hasn't started his/her roll, I will not be impressed. Wait until the aircraft has begun to roll at least. :ok:

[Dr. Evil]

It is therefore more expeditious (if that is what you meant?).

Exactly! Keep the ball rolling... since a line-up instruction when the previous is already airborne or half way down the strip is too late and the customers will end up with wasted time on terra firma :=

[Barnaby the Bear]

Some customers are best left on terra firma! :E :E :ugh: ...Who said that!!!!? :oh:

[Giles Wembley-Hogg]

Barnaby

Since I often have to depart from T4 and we are often only cleared to taxi to S1N/S and then given a conditional line up, it makes sense to commence the taxi (including starting round the corner) before the traffic ahead has started rolling, or I won't be aligned with the centreline as the preceeding gets airborne.

G W-H

[GT3]

Does pulling you forward to SB1 a few minutes prior to your turn help in this case?

[Giles Wembley-Hogg]

GT3

In the main I'd say "yes". I am afraid that the answer is not entirely straightforward. Approaching SB1 after having taxied via S1N can leave us at a bit of an angle at SB1. If we have to stop and then start again from here it can mean large thrust applications which we try to avoid for noise/environmental reasons. If we are light, however, this is not a problem as the aircraft will move off at idle and then we can turn the tiller full over to the left and there is enough power to keep us moving.

Ideally there would be a holding position just a bit closer to 27L (unfortunately infringing the GP), but failing this a pre-emptive (albeit slightly outside of MATS pt2) clearance to pull "round the corner" is great.

... Or I could just carry on doing what I do now which involves me going around the corner as soon as the departing aircraft starts to line up and timing my taxy so that as it starts to roll I am outside the blast, but entering the runway. Needless to say I am not a mind reader, so sometimes I may have to stop before the runway but after the CAT 1 hold, which may upset Barnaby, but is actaully still in accordance with my clearance (as I am still "after" (geographically) the departing).

Ask 2 pilots or 2 ATCOs and you'll get 3 answers though!!

G W-H

[GT3]

Fair enough, is it busses or large aircarft you fly?

The holding points south of 27L/09R at both CATIII and CATI are not great with regard to expedition. However hopefully the MLS install will solve this wrt landing traffic.

[Giles Wembley-Hogg]

757/767. Just the 767 from T4 these days.

[Dr. Evil]

Ask 2 pilots or 2 ATCOs and you'll get 3 answers though!!

Wrong !!! 4-5-6 or more depending on the moons position :E :E

[Barnaby the Bear]

Its difficult to upset me really. Thick fur! :}
I was more confused about the reduced separation in the vicinity?

[Giles Wembley-Hogg]

Ah, Mr Bear, I'm with you now. I just want to be in a position for the friendly (and possibly hirsute!) ATCO to be able to seize upon any opportunity for expedition that he or she can find - not still trundling along the long link past SB1.

G W-H

[ATCO2]

Hi,

The word "after" in this case of conditional clearance shall be replaced by word "behind"(phraseology says). In my opinion, no one of pilots will line up immediately behind departing/landing acft. Conditional clearance in this case may be given but pilot will decide how many seconds to wait to commence a line up behind. I instructed many times acft to line up behind but nobody did it immediately. All of them waited for a while and then did it, specially if the behind acft is lighter then previous one if they enter and depart from the same holding point.

BRGDS

[MrApproach]

The whole idea of the conditional clearance is to save time by putting the onus onto the pilot to comply with the instruction when he/she considers it is safe to do so. (Emfarsis on the last nine words) Hence the aircraft "creeping" forward as the previous rolls is doing the right thing and saving time that might otherwise be wasted because the controller was talking to another aircraft or another controller. Any controller who further interprets the instruction or adds caveats should go back to my first sentance. Any controller worried that a pilot may be too slow to line up because there is an aircraft on final should consider giving the pilot the situatonal information. "Behind the 737 rolling runway ... line up behind, additional traffic on four mile final." If the pilot wants to take his/her time he/she should decline.