Airport - Airline and Air traffic control

These are three major actors of airport life, and air transport industry.

From the point of view of a PAX (remember, the "code name" for passenger), the role of the airline is quite easy. Operate the plane safely.

ATC is a bit more mysterious, but anyone already heard about the guys in "tower" giving clerarances to planes. There is much more to tell about ATC, but for the time being, this is enough. Just keep in mind that ATC is responsible to keep planes separated from each other, and in european context to have them respecting their departure time "slots".

The third A - Airport authority - is even more transparent to a PAX, but it plays a major role. These guys are in charge of runing the airport itself, which from operational point of view means airplane parking management, providing power and air-conditionning to planes while they're on ground, and so on.

Short break here for a funny thing to look at during your next trip. Each time a plane taxies (drives in) into its stand (parking place) one off the ground staff plugs an electrical cable below the plane nose. This is not to charge the plane batteries, but to provide it with ground produced power. This frequently occurs even before the engines are stopped... because most of ground services fees are based on how much time power was supplied to the plane, as it is easy to measure. Next time you're waiting, look at the powerplug guys.

Now, look at the various interests of our three actors.

Airlines want short ground times, as they earn money by flying and respecting their schedules.

Airports want to sell services to planes, based on the time they stay... but on the other hand, they are payed per passenger and per landing, so they want to be expeditious, but not too much.

ATC want to keep planes on schedules, and avoid traffic congestion. And under some circumstances, delays are imposed to planes, to avoid congestion at destination or enroute.

Now they all have secondary wishes. Typically, airlines want convenient schedules for their PAX, and possibly easy to memorise. Who would like to leave europe to the states in the evening, and be there at night ? Also take a look once at the departure panels, and try to count the number of flights leaving, let's say, at 08h00. Having 5 or 6 of such flights at airports with a single runway is by far not uncommon, but as ATC has to separate departures by at least one minute (sometimes more), how the hell could it be possible to have 6 departures within the same minute ?

The funny thing is that ATC can not refuse a flight plan, airport authorities can impose airport slots to companies, but no one is co-ordinating all of that by the minute, and in fact this is quite good, because PAX themselves are frequently out of control. How could you expect 200 travellers to reach the plane, all on time, with no boarding problems, no one being "delayed" by shopping, or just being late ?

So airlines, airports and air traffic control all know that all the 08h00 planes won't leave all at the same time, and that's what makes the traffic situation different each and every day. Nothing in common with trains !

One more thing, about slots. When a flight is imposed a slot, it means that the flow control unit managing all of european sky from Brussels computed its departure time to avoid any congestion en route or at destination, but as we've just seen, the departure time can not be by the minute, so a slot is valid for 20 minutes, 5 before the computed take-off time (CTOT) and 15 minutes after. If your captain can not manage that... you need a new slot, which can be 2h later.

This can look bad, but I'm sure that as a PAX, and particularly if you're ecologist, you prefer to wait on ground than in the air, don't you ?

So next time your captain says that you missed your slot, ask yourself if there were delayed passengers, or if you're flying to a busy airport... and if you get off the plane because the new slot is too late, be sure that:
1) Airline is getting mad about not earning money in flight
2) ATC is happy you're not causing congestion and remain safe
3) Airport Authority is really happy to sell more power to your airline, and to welcome you in the shops and bars

A tip to close this post: if you're delayed and not yet on board the plane, don't forget to ask ground staff (airline or handling agent) to give you a drink / sandwich voucher. They will never refuse, but will never offer that spontaneously.

Have a safe flight ;-)