Can someone explain ''Slots'' to me

chillin117

I have read over the years of slots in Heathrow selling for zillions and that might be for only a couple of slots per week. What happens if you miss your slot due to weather etc. ? How long is a slot left open for, An hour ?
Does it mean Heathrow is at full capacity or is it decided by aircraft type ?
A Layman's link would be great too, Thanks..... !:)

BonkeyDonker

chillin117 wrote: »

I have read over the years of slots in Heathrow selling for zillions and that might be for only a couple of slots per week. What happens if you miss your slot due to weather etc. ? How long is a slot left open for, An hour ?
Does it mean Heathrow is at full capacity or is it decided by aircraft type ?
A Layman's link would be great too, Thanks..... !:)

They are landing and departing slots. All runways have a finite capacity so in very busy airports you need to buy a slot pair. These give an airline a time for both landing and departures and through this regulate traffic flow and capacity.

There is usually some flexibility in the actual arrival time however to allow for weather, delays etc.

However, some slots pairs (early morning arrivals etc) are worth more than others as they are at a time when people, particularly high paying premium customers, want to fly. Hence why some are worth more than others.

As for Heathrow - it is running at 100% hence the constant talk about building a new runway.

chillin117

BonkeyDonker wrote: »

They are landing and departing slots. All runways have a finite capacity so in very busy airports you need to buy a slot pair. These give an airline a time for both landing and departures and through this regulate traffic flow and capacity.

There is usually some flexibility in the actual arrival time however to allow for weather, delays etc.

However, some slots pairs (early morning arrivals etc) are worth more than others as they are at a time when people, particularly high paying premium customers, want to fly. Hence why some are worth more than others.

As for Heathrow - it is running at 100% hence the constant talk about building a new runway.

In plain English too, Thank you

chillin117

chillin117 wrote: »

In plain English too, Thank you

I think that is a rather clear and concise explanation to be honest.

chillin117

Deleted User wrote: »

I think that is a rather clear and concise explanation to be honest.

That's why I thanked him ?

chillin117

chillin117 wrote: »

That's why I thanked him ?

Sorry my bad I misread your post.

chillin117

Deleted User wrote: »

Sorry my bad I misread your post.

No problem

Tenger

Slots can have 2 different meanings. The above example of Heathrow is based on it being such a congested airport. No new airine can just decide to start a route to LHR. They essentially have to purchase the timeslot to start a new route in/out as the airport is at 99% capacity.*

At other time you might be on a flight and may heard the announcement that we are waiting for our take-off slot. This is permission from ATC for your particular flight to take-off and commence its journey. This restriction may not be due to congestion at your origin, it could be enroute congestion or at your destination. But it means you are being held until a certain time so that if you take off at x o clock you will be lined up to slot into the gap that is there for you on your planned route to your destination.

Hope that helps.

*(One airline went mad 2 years ago and bought a particular slot pair for E60M, which had some people estimating the value of EI at over E2.5 Billion as they have 17 slot pairs. The selling airline were quoted as saying the price was triple the normal rate so they couldnt refuse.)
I think it was SAS selling to Qatar?

basill

And then they can disappear to.....Like that time we had a Eurocontrol ATCO on board who made a phone call. We got an ACARS from company saying send a cup of tea down to x seat number thanking him for making your slot vanish:)

Locker10a

basill wrote: »

And then they can disappear to.....Like that time we had a Eurocontrol ATCO on board who made a phone call. We got an ACARS from company saying send a cup of tea down to x seat number thanking him for making your slot vanish:)

Ah yes I'm also familiar with this, sometimes it's very convenient having a controller in the family

stoplooklisten

basill wrote: »

And then they can disappear to.....Like that time we had a Eurocontrol ATCO on board who made a phone call. We got an ACARS from company saying send a cup of tea down to x seat number thanking him for making your slot vanish:)

I don't understand what happened here.

He was on the plane and made the slot vanish?
Does that not mean the plane couldn't land? Why wouldn't he want the plane he is on to land...until he had tea?

bkehoe

stoplooklisten wrote: »

I don't understand what happened here.

He was on the plane and made the slot vanish?
Does that not mean the plane couldn't land? Why wouldn't he want the plane he is on to land...until he had tea?

This was referring to an air traffic control slot, sometimes referred to as a CTOT (calculated time of takeoff) or 'regulations' and common at busy periods or when the French are on strike which reduces the amount of en-route traffic they can accommodate for example.

If the slot disappears then the aircraft is free to take off at their flight planned time window.

In the example airport slots, e.g. LHR, the flight simply has to be flight planned to arrive/depart at the times in the slot pair. If the flight is late or delayed they don't get refused permission to depart/arrive.

Tenger

Picture the sky over Europe like a conveyor belt, better yet a system of criss crossing conveyor belts......there are a finite number of spaces on those conveyor belts. Each conveyor belt is an air traffic control zone. Each can only handle so many aircraft at only one time, each needs to have a certain amount of space between each aircraft.
To get to your destinations you might have to pass along 3-6 of these belts along the way. So you might be given a CTOT of 40 minutes from now...this will line you up to slot into a gap which will be there for you on the next "conveyor belt" when you take off.

*I am just back from Lidl hence the analogy...... Looking down at a peak traffic M50 might be another analogy. The sliproads are blocked until a slot appears on the main M50 itself.



And as basill pointed out the ATC staff themselves are able to allocate prioriy to certain aircraft and circumvent the system as required. Thus they will always know which aircraft their colleagues are traveling on. I can remember a flight fron the US, a little before departure, ATC/ground control gave instructions to the flight deck and also 'casually' mentioned that a colleague was onboard. An immediate call to the head of cabin crew was made, "find Mr. ATC, reseat him at the pointy end in a big seat, ASAP" Once the aircraft pushed the ground instructions where amended to gave priority taxi to the aircraft.
As in so many walks of life, its who you know and being nice to everyone just in case it comes back at you later on.

Negative_G

Off topic slightly but if the aircraft has a status type in field 18 of the FPL, this too can exempt the aircraft from ATC restrictions and slots.

STS/HEAD which means that a head of state is on board, is exempt for example. The full list is available on the eurocontrol website.

Bsal

https://www.youtube.com/watch?v=OTNz74rrOq0

cson

LHR slots are big business; Virgin raised finance using their slot portfolio as security late last year.

http://www.airfinancejournal.com/Article/3516281/Update-Virgin-Atlantic-issues-220m-bond-against-Heathrow-slots.html

Tenger

cson wrote: »

LHR slots are big business; Virgin raised finance using their slot portfolio as security late last year.

But like the housing market,slot pairs in congested airports can vary greatly in value and are just fictional value unless you have a buyer. On the other hand if two buyers want what you got then you can get well over notional market value.