Landing early before slot time
 

If an aircraft lands at a slot controlled airport (eg Gatwick) more than about 20 mins before its target slot time, various people like ACL start to get annoyed and eventually fines are issued if this happens repeatedly

I can understand that abuse of slot times at Heathrow in peak times in 2019 would not have been a good idea. However, with airports running at significantly reduced usage currently, there is presumably a lot more slack in the system. About a week ago, I flew from an empty beach airport in Europe to Gatwick at lunchtime - doors were closed over 35 mins (yes, really) before scheduled departure time, captain verbally acknowledged on PA that everything was in order, but there was still a 20+ min delay before pushback / engine start... the aircraft reached its stand 15 mins before scheduled arrival time

Would contacting ATC and asking for advance permission to arrive even earlier likely have been possible and sufficient, or would there be a whole series of consents to gain making it not worth the trouble involved ? Do some airline ops departments clamp down on early arrivals ? The weather was average and no particular visibility concerns or rain. With Gatwick so underused right now, I have difficulty believing the runway or terminal couldn't handle early arrivals.

It’s been a while, so forgive me if I’m out of date, but as far as I remember, ATC have no knowledge of an operator’s “runway slot time”. This is arranged directly with the Airport Authority by the aircraft operator. The trick is to merge this with any possible ATC slot constraints, which normally only apply to the departure airport.

I once arrived about 2 hours early on a ferry flight at LHR. We knew that we were way ahead of the allocated time but didn’t fancy hanging around at the airport of departure. ATC were happy to let us land but our Airline management lost their sense of humour when “Heathrow Airport Limited” raised a complaint.

So, the Captain will be made aware of any arrival slot times and will liaise with ATC at the airport of departure to achieve a take-off time that fits, subject to any other “flow control” measures that may be invoked by en-route ATC.

Hope this helps to explain what you experienced.

As to why Gatwick were so strict about slots, given the lack of traffic, I have no idea.

A couple of things come to mind on this:
1. Gatwick is presently operating North Terminal only and even though movements are a lot less, if a flight arrives a lot earlier than scheduled then there may not be a suitable parking contact stand available. The alternative would be to park remote which could result in no busses being available for a while or not at all.
2. Ground handling may also not be available immediately if arriving much earlier than scheduled with the handling teams not planning for the early arrival and occupied with other flights. .

A CTOT (slot time) can be applied to a route for an number of reasons and unless you speak to operations you will not know where in your route the restriction is. Firstly, a flight plan, if unrestricted, is for a departure + or - 15 mins of the SDT (-5/+10 for CTOT). You may try and change the departure time but you may them pick up an unfavourable CTOT. If you are unrestricted, as has been mentioned, the arrival airport will expect you somewhere close to the STA. Its resources, and those of the ground agents, are aligned to schedules, they dont have crews just sat around waiting for aircraft to pitch up! On the rare occasions I was running ahead of schedule, I found it best just to wait and have another coffee.

As Capt says, a flight has a flight plan with an EOBT (estimated off blocks time). You cannot start up over 15 minutes before or 15 minutes after that time. So if you are ready to go, you have to wait. This time cannot be bought forward only delayed so asking if you can go earlier will get a negative response. The only way around it is to cancel the flight plan and refile for an earlier time. The risk with this is that you may then get a slot as you have dropped out of the system and then you are joining at the back of the queue. All the info is on the Eurocontrol website and is to avoid the need for more flow than is normally required.

Now if the airport is ACDMed, that's even more/less complicated depending on your point of view.

As the previous posters have explained, there's the CTOTs and the EOBTs (ahh joys of ACDM...)
Then there's also the airport slots. Some are flexible, some are absolutely rigid. ATC have no real influence over the airport slots. Yes, it does become a real headache when you have an airport slot restriction and a CTOT an hour after your departure. Not much you can do other than call "ready" at the original departure time (-15 minutes) and see what happens.

Last year I only had 1 CTOT and a handful of airport slots, now it's back to "normal".

Some airlines do have internal policies that do not allow them to leave earlier than 10 minutes before their planned EOBT. Although it is possible to do so, yes, even more than 15 minutes, recently did it more than 2 hours before the flight plan was filed (in error i might add), it just took the local ATCO to activate the flight plan earlier.

I always used to cringe when the Capt crowed about landing 'early' as most times you just ended up either in the hold or parked waiting for a gate after landing LOL.

My experiences suggest that 'early arrival times' are often 'helped' by slightly generous flight time durations in the published timetables ... and :ok:+1 to longer ron on his observations!

The expansion of flight times to allow for delays spread outwards from LHR, I think. Now everyone does it. The other key change was placing the listed departure time much earlier, to try and ensure that Pax got to the gate on time. People started to stay: "We took off 40 minutes late ..." which they did not. You cannot detail all the times for Check-in; Hold; Gate; Doors; Off Blocks; Runway times.

The focus of this started when:

• Consumer groups and govts started ranking carriers in punctuality
• CEOs and Boards of Directors had hysteria
• Crews were told to hurry things along
• Crews pointed out that the whole mix of systems in Europe was a bit more complicated than that
• The kids in Marketing quickly thought up things
• Problem solved
• The media / govts / Directors moved on to the next panic.

Yes, I know that's a rather casual way of looking at it but I've worked in many corporate spheres for over 40 years.