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VB
28th Feb 2004, 16:45
Any LGW ATCO out there who can explain what determines the order of departures at LGW. Some things are obvious like alternating the deps on different routes (eg. LAM and SAM departures off 26L ). Over the years have heard many different theories eg. push-back order determining the take-off order , but have also heard a lot of frustated pilots talking about being there for a long time and then a " Speedbird " turning up and going ahead of every body ! So what really determines the order ?:confused:

tigtog
28th Feb 2004, 18:46
VB,

Runway utilisation is the name of the game at EGKK, ie we try and (ideally) have one aircraft movement on the runway every minute.

In order to achieve this we have to either be in what we call "one in one out" ie. 1 land , 1 departs, 1 lands, etc or if we don't have enough inbound traffic to do this we have to ensure that aircraft fly diverfing tracks after departure otherwise we have to separate them by five nautical miles which prevents us from having one a/c movement per minute.

To achieve good rwy use we sometime have to skip the queue with certain a/c at the holding point ie if we have 9 Southampton deps to go (SA after dep) and only 1 lambourne(right turn after dep) the chances are the Lam will be routed to an empty hold and then departed fairly quickly.

We also take into account tight slot times etc which sometimes alters the dep order. Vortex wake is another consideration.

As for a "speedbird" jumping the queue for that reason alone , all I can say is" Absolute B*%$ocks!!!".

Pilots who make comments like that should remember the time that they were allowed to go to Mike One because of a tight slot or an intersection dep because they were a "right turn out" and should rest assured that we do evreything for a reason and we try and help ALL companies to the best of our ability.

Hope this helps clarify things VB. cheers for now,

Tig.

Dan Dare
28th Feb 2004, 18:58
Not just Gatwick, but the list of choices is VERY long including:

Who wat there first?
Who was ready first?
Who was most delayed on the way to the hold?
Which has a tighter CTOT?
Which is likely (based on experience) to play ball and take-off without delay in the very small gap available?
There could be a slightly bigger gap available which, with the right pairing, could allow two to depart rather than the lumbering aircraft, which could depart in the next, normal gap.
Not wanting to overload any area sectors by sending too many in the same direction too quickly.
There may have been a slow aircraft launched 6 minutes before you got to the hold, which could still affect your departure.
Combining departures so that there is no wasted time on the runway waiting for vortex.

I'm sure the vast majority of controllers put their professionalism in gaining maximum runway utilisation ahead of any desire to please the speeding bird or penalise whichever airline is todays villain airline.

Musket90
28th Feb 2004, 23:22
Gatwick and other busy airports have a runway hourly declared capacity which means airlines are allocated a scheduled arrival/departure runway slot (not to be confused with ATC flow control slots). If airlines operate on time in accordance with these runway slots then the number of flights offering to arrive or depart should be comfortably handled by ATC with delays kept to a minimum. If flights do not run to time then you often have a situation of too many offering to arrive or depart within a given time period and ATC just can't physically shift them on the runway quick enough without incurring longer than normal delays. So the ramp handling and terminal building processes must ensure an on time departure so the arrival stack or departure holding point does not get too congested.

Not Long Now
29th Feb 2004, 02:03
No no no the gatwick bods have the heathrow frequency dialled up and wait for heathrow to launch a dover before they then launch a lambourne, it's obvious.

Jerricho
29th Feb 2004, 02:13
But the Dover has to stay on the SID, and there has to be an LL inbound upwind off Biggin.

av8boy
29th Feb 2004, 14:13
Ah, the sing-songy refrain of controllers working airports with conflicting departures...

Some years ago I was employed at at TRACON wherein, at roughly 0617 every business day, there'd be exactly the same mess to sort out. I'm not talking a departure rush, per se... Rather, it was a small number of fast and moderately fast aircraft departing three different runways and making me work for my pay before I was finished with that first cup of coffee. Twenty minutes later there'd be an actual departure rush, but no 15 aircraft on freq at the same time ever made me work as hard as those three first thing in the morning. Guess it made the rest of the day seem easier anyway...


'Tis the same, world-wide, ain't it!?!

Dave
:)