Conditional clearance and intermediate holdingpoints
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Conditional clearance and intermediate holdingpoints
Aircraft departing from 26L in LGW are usually cleared to taxi to the intermediate holdingpoints A2 or A3. Frequently these aircraft will get a conditional line-up clearance afterwards, e.g. after the boeing 737 on finals line up and wait behind (forgive me for mixing up of Cap 413 and ICAO 
).
Now my question is this: if I am cleared to hold at A2 or A3, and subsequently get the conditional line up clearance, am I then allowed to pull forward to A1, the last holding point, whilst waiting on the aircraft on final to pass by? To my knowledge this is not allowed since my last clearance was to A2/A3, but I see a lot of collegues doing this anyway. So I wonder..
).Now my question is this: if I am cleared to hold at A2 or A3, and subsequently get the conditional line up clearance, am I then allowed to pull forward to A1, the last holding point, whilst waiting on the aircraft on final to pass by? To my knowledge this is not allowed since my last clearance was to A2/A3, but I see a lot of collegues doing this anyway. So I wonder..
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To my knowledge this is not allowed since my last clearance was to A2/A3
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You can expect me to do as I'm told, or as the rules stipulate. You can't expect me to leave my last cleared position just because I think that is what you expect me to do. To make it more interesting, on runway 08R aircraft are specifically told to taxi to J1 prior to getting a conditional clearance! If that is what they expect me to do, why don't the just say so on 26L?
Don't get me wrong, I absolutely agree with you that ATC probably expects me to start taxying forwards to A1, but I need a reference for this, otherwhise it leaves me wide open to all sorts of criticism.
Don't get me wrong, I absolutely agree with you that ATC probably expects me to start taxying forwards to A1, but I need a reference for this, otherwhise it leaves me wide open to all sorts of criticism.
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ATCO at Gatwick here, so here goes!
When you're given a conditional line up from A2 or A3, you can start to move when you wish, so long as you don't pass A1 until the landing a/c passes you. The reason we don't generally use A1 is that a) it's such a short distance that aircraft will often end up stopping and then having to apply breakaway power again to enter the runway and b) the rules only let us use A1 from A3, not A2. You will sometimes see A1 used from A3 but it's not all that common (usually a last minute change of plan if a gap tightens up too much and an aircraft has already passed A3)
On 08R both J7 and J4 are further away from the runway, so we'll try to get you a bit closer (especially if we're working tight gaps). There's an additional problem at J4 because of the earth bank - anything smaller than a B757 can't generally see the landing traffic at the range we try to issue conditionals (2 to 3 miles) so we need to move you forward to J1 - once your nose is clear of the bank we can then give the conditional clearance legally. With some heavy aircraft we try to give a longer run to help up the hill at J by issuing the conditional from J7 or J4, but in practise this usually causes more problems than it creates by making the time onto the runway much less predictable (and the gap less likely to work, and the next lander having to go around....well, you get the idea
)
Hope this helps
When you're given a conditional line up from A2 or A3, you can start to move when you wish, so long as you don't pass A1 until the landing a/c passes you. The reason we don't generally use A1 is that a) it's such a short distance that aircraft will often end up stopping and then having to apply breakaway power again to enter the runway and b) the rules only let us use A1 from A3, not A2. You will sometimes see A1 used from A3 but it's not all that common (usually a last minute change of plan if a gap tightens up too much and an aircraft has already passed A3)
On 08R both J7 and J4 are further away from the runway, so we'll try to get you a bit closer (especially if we're working tight gaps). There's an additional problem at J4 because of the earth bank - anything smaller than a B757 can't generally see the landing traffic at the range we try to issue conditionals (2 to 3 miles) so we need to move you forward to J1 - once your nose is clear of the bank we can then give the conditional clearance legally. With some heavy aircraft we try to give a longer run to help up the hill at J by issuing the conditional from J7 or J4, but in practise this usually causes more problems than it creates by making the time onto the runway much less predictable (and the gap less likely to work, and the next lander having to go around....well, you get the idea
)Hope this helps
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Try thinking of it this way - your previous clearance (to A2 or A3) has been superseded by the new one ("after the landing, line up"). The new clearance allows you to move forward as long as you follow the condition and don't enter the runway (i.e. pass the cat 1 hold at A1) until after the landing.
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Try thinking of it this way - your previous clearance (to A2 or A3) has been superseded by the new one ("after the landing, line up"). The new clearance allows you to move forward as long as you follow the condition and don't enter the runway (i.e. pass the cat 1 hold at A1) until after the landing.
Unless I get told "taxi hold A1, after the landing...., line up" then I am not going to go to A1 and hold there. I look forward to being corrected, however.
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Unless I get told "taxi hold A1, after the landing...., line up" then I am not going to go to A1 and hold there. I look forward to being corrected, however
A conditional clearance is exactly the same as any other, except that it's subject to a condition ("the landing aircraft"). In this case the condition prevents you from entering the runway, not from starting to move.
Per Ardua ad Astraeus
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No, nor would I go to A1. I might start 'creeping forward' (timed to perfection, of course) with the other traffic on short final, but no way would I go onto the ski-ramp to hold and then blast matey behind as I power up again. In any case, there is AMPLE time to get into position from A2 or A3 unless the traffic is an Islander/Twotter.
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BOAC, without a doubt your method is best for all of us (timed to perfection of course) but the authorisation to move is what PENKO was asking about and what I tried to answer.
To repeat, any ATC clearance constitutes "an authorisation to proceed in accordance with any specified restrictions." A conditional line-up clearance means you can start to move, provided you don't enter the runway (i.e. pass A1) until after the landing traffic. The ideal method is to time the move to perfection so you don't need to stop at A1 as you do so, as BOAC quite rightly says.
And believe me, performance in getting onto the runway is nowhere near as guaranteed as you might think - sometimes this is due to the aircraft type (heavies in particular have a lot of inertia to overcome), but there's nothing to get the adrenaline going like seeing an A320 (for example) just entering the neck at A1 with the previous lander already turning off on an RET and the next lander 3 miles out
I'm out of here now!
) but the authorisation to move is what PENKO was asking about and what I tried to answer.To repeat, any ATC clearance constitutes "an authorisation to proceed in accordance with any specified restrictions." A conditional line-up clearance means you can start to move, provided you don't enter the runway (i.e. pass A1) until after the landing traffic. The ideal method is to time the move to perfection so you don't need to stop at A1 as you do so, as BOAC quite rightly says.
And believe me, performance in getting onto the runway is nowhere near as guaranteed as you might think - sometimes this is due to the aircraft type (heavies in particular have a lot of inertia to overcome), but there's nothing to get the adrenaline going like seeing an A320 (for example) just entering the neck at A1 with the previous lander already turning off on an RET and the next lander 3 miles out
I'm out of here now!
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So if you're at A2 and given a clearance to "line-up 26L" you wouldn't move forward until instructed to hold at A1?
A conditional clearance is exactly the same as any other, except that it's subject to a condition ("the landing aircraft"). In this case the condition prevents you from entering the runway, not from starting to move.
A conditional clearance is exactly the same as any other, except that it's subject to a condition ("the landing aircraft"). In this case the condition prevents you from entering the runway, not from starting to move.
