ironmouse

Probably a really boring/insignificant question, but..
Looking at the LHR-GVA schedules the flight durations are:

13:10 1hour 35m
14:00 1 hour40m
15:00 1 hour 45m
16:35 1 hour 40m

All the same A320 all the same distance? so why the small flying time difference?

Tobias-UK

It will be because of anticipated congestion at departure and/or arrival airports.

bermyandy

2pm onwards is probably considered the chairmans flight... more people will have had a big lunch, plane weighs more... takes longer...

Brisbane Road

Slow day at work?

scottishpoet

Flight times from GLA into heathrow vary from 1hr 35 to 1hr 15

RGS5526

Its probably due to the variation in anticipated time spent waiting for a gate or in the queue for the runway.

Back in the days of Trident and the Shuttle, the scheduled time was almost always 70 minutes, but Captain Speaking usually announced as we left the gate "Our flight time today will be 60 minutes" and we were actually in the air for 50 minutes.

Often1

Carriers, BA included, estimate the block time for flights based on averages. On short-haul flights, ground time on departure and arrival takes a disproportionate percentage of that block time. Thus, the varying scheduled arrivals.

fluffymitten

On a related/not-related note, I always wondered if it had something to do with airport slots too. There's always talk about buying slots at, say, Heathrow but surely there's a corresponding slot at the destination airport too and maybe that plays into the varying block times?

wilsnunn

I had always assumed that this was the case too, it will be interesting to hear if this is indeed true.

john205

Taxi-ing time can vary greatly also.. they could be clever in take in to account something to do with that at LHR perhaps, including planned runway alternation but I doubt they are that clever

scottishpoet

it is padding to allow for delays, especially in and out of LHR

most airlines do it, not just FR!

TheOldMan

Head wind ?

maastrichtmouse

And what happens if the wind is late?

Waterhorse

Actually, all our departures use the expected taxi time and runway into account. Historical data in aanalyzed for every route to predict the fuel required for the coming period.

As you can imagine small over, or under, estimates of fuel can, over a long period, cost small fortunes in money spent to no point or last minute purchase of additional fuel. We also look at opportunities to reduce fuel cost by "tankering" ie carrying fuel for the return leg if the fuel is cheaper at base. To do all this we look at historic fuel burn and sector length, including statistical holding and taxi times.

Sector lengths vary with time if day and time of year, but must be married to slot pairs so may vary just to fit - it is both science and art, but it is important to get right .