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Topic: LHR GMT To BST How Does It Work
Username: sierra3tango
Posted 2013-03-30 23:56:26 and read 4049 times.

Was watching LHR long haul arrivals this morning (on Flighthradar) with all the usual flights lining up on approach at (roughly) the same time UTC. Then recalled that this morning the LHR clocks have gone forward GMT to BST so in fact they were lining up on approach an hour later, local time.

Shorthual presumably isn't a problem (especially as its a Sunday morning when the SH schedules have some slack in them) but the LH fleets on whatever airline do what? Turn them all around with an hour's less ground time or what?

Continuing the thought what happens when the clocks go back the other way in October all these LH flights can't hold for an hour (due to the night time ban at LHR), presumably they depart their orginating airport an hour later, or what?

Topic: RE: LHR GMT To BST How Does It Work
Username: YXD172
Posted 2013-03-31 00:22:46 and read 3998 times.

Quoting sierra3tango (Thread starter):
presumably they depart their orginating airport an hour later, or what?

You've got it! Most schedules have different timings before and after the time change, especially when flying between two airports that change to/from Daylight Savings Time on different dates (such as North America to/from Europe, where flight times in between the changes are different for a few weeks.

Topic: RE: LHR GMT To BST How Does It Work
Username: sierra3tango
Posted 2013-03-31 01:56:09 and read 3773 times.

Quoting YXD172 (Reply 1):
You've got it! Most schedules have different timings before and after the time change, especially when flying between two airports that change to/from Daylight Savings Time on different dates (such as North America to/from Europe, where flight times in between the changes are different for a few weeks.

Don't think I have got it ! The point was that (most) inbounds from the east (not so sure about the west) were arriving an hour (local time) later than normal (but the same time UTC), or to put it another way they must have departed their originating airports at the same time as 24 hours previously. So do they have a faster turn at LHR around to go out on schedule??

Topic: RE: LHR GMT To BST How Does It Work
Username: fca767
Posted 2013-03-31 02:41:20 and read 3677 times.

Quoting sierra3tango (Reply 2):
Don't think I have got it ! The point was that (most) inbounds from the east (not so sure about the west) were arriving an hour (local time) later than normal (but the same time UTC), or to put it another way they must have departed their originating airports at the same time as 24 hours previously. So do they have a faster turn at LHR around to go out on schedule??

Some just stay on GMT like emirates at manchester will now depart at a different time all summer

Topic: RE: LHR GMT To BST How Does It Work
Username: rutankrd
Posted 2013-03-31 03:03:05 and read 3615 times.

Quoting sierra3tango (Reply 2):

Quoting YXD172 (Reply 1):
You've got it! Most schedules have different timings before and after the time change, especially when flying between two airports that change to/from Daylight Savings Time on different dates (such as North America to/from Europe, where flight times in between the changes are different for a few weeks.

Don't think I have got it ! The point was that (most) inbounds from the east (not so sure about the west) were arriving an hour (local time) later than normal (but the same time UTC), or to put it another way they must have departed their originating airports at the same time as 24 hours previously. So do they have a faster turn at LHR around to go out on schedule??

There are a few slot changes that take place in the very early mornings.

During the Winter scheduled the first arrival is normally at 04.40 GMT from Boston this advances to arrive using a 06.15 BST slot in summer timetable.
During the northern summer the first scheduled arrive is at 04.50 BST and is from Singapore.

Clock change always takes place Sunday am and Heathrow actually has some flexibility - Not all slots are used till about 11.00 am as many inter European business services don't operate.

It really isn't that difficult.

What does cause more scheduling issues are the few weeks when the US States (That change the clocks) and Canada are out of sync with Europe in Early March add the winter high winds and you get the situation where US inbounds with scheduled slot times of 06.00 -07.00 can enter the TMA as much as an hour and half early!

Due to the slot limitations before 06.00 these end up entering the stack for as much as 40 minutes before being vectored.

All European countries sync the clock change and as LHR has virtually no InterEurope over night traffic the schedules are not effected.

Topic: RE: LHR GMT To BST How Does It Work
Username: Viscount724
Posted 2013-03-31 16:34:56 and read 2875 times.

Quoting rutankrd (Reply 4):
What does cause more scheduling issues are the few weeks when the US States (That change the clocks) and Canada are out of sync with Europe in Early March add the winter high winds and you get the situation where US inbounds with scheduled slot times of 06.00 -07.00 can enter the TMA as much as an hour and half early!

Many airlines change their schedules during those periods to keep the times constant at one end or another. In the case of flights to/from LHR I would guess the times at LHR are more important due to slot limitations.

For example, for the past 3 weeks since Canada went on summer time but Europe was still on winter time, AC flights to LHR have been departing Canada one hour later than usual in order to arrive in LHR at the same time which is important for connections. As of Saturday night, the departure times reverted to the usual times.

Topic: RE: LHR GMT To BST How Does It Work
Username: cloudyapple
Posted 2013-04-01 03:43:19 and read 1625 times.

Quoting sierra3tango (Reply 2):
but the same time UTC

This is the key. In scheduling, airline ops and ATC terms, we operate in UTC. This is regardless of who and where. Even in China. Any schedule in local time would be a conversion from the master schedule in UTC.

Topic: RE: LHR GMT To BST How Does It Work
Username: VV701
Posted 2013-04-01 06:05:15 and read 1466 times.

Quoting Viscount724 (Reply 5):
Many airlines change their schedules during those periods to keep the times constant at one end or another. In the case of flights to/from LHR I would guess the times at LHR are more important due to slot limitations.

LHR Winter Timetable Slots are entirely separate to LHR Summer Timetable Slots. Indeed there are currently 2.5 per cent more weekly slots during the Summer Season (9,524 in both Summer 2011 and Summer 2012) than in the Winter Season (9,296 in both Winter 2011-12 and Winter 2012-13).

Despite this difference - see the Airport Coordination Ltd web site - many individual airlines have the grandfather rights to slots at the same time in both the LHR Summer and Winter Timetables. However some flights change their times at the end of each season as their operator has obtained Winter slots at different times to their Summer slots.


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