The window is there solely for ATC use, to allow for taxiway and holding point congestion which might prevent an aircraft getting airborne at its Calculated Take Off Time (CTOT). ATC can, and often do, apply their discretion of course and use it to make up for operator shortfalls, but that's not ultimately what it is in place for. On that basis, pilots have no right to demand its application for their flight.
It really makes me sick to read such formal justifications of that sick european slot system.
What are the facts ?
1. Aircraft ready to go have to wait, because of their slots. When finally released they burn max fuel to gain some minutes back.
2. Aircraft not ready to go are pushed to reach their slots.
(I tried to take off without flaps two times - I caught me taxiing with 40 knots.
Am I the only one making mistakes in a hurry to reach a slot ??? )
Various incidents do proof, that this is the opposite of a system that should support
flight safety.
3. Flights delayed by ATC pay the same ATC Fees as flights not delayed by ATC.
4. Every flight can be sabotaged by ATC by sticking to the rules: example:
You request start up at CTOT -20. They say: "Standby for start due to your slot."
You get start up at CTOT -10. You wait for push around 10 min. - you taxi 15 min,
and then you hear: "you just missed your slot"
I never experienced this in Spain so far. But in Germany (FRA,MUC,DUS) and Italy (FCO) this is "normal" procedure.
Some more facts about "slots" and flight safety:
You have a one hour deicing queue. You have a slot starting in 30 min. They tell you: "You will not make your slot, call your operator". You ask:
" What CTOT shall i try to get ?" ATC answers: " I donīt know [...and I donīt care]".
You organize a new slot. You get deicing. Hold over time is running out, waiting for your slot. IS THIS FLIGHT SAFETY ? This is bull****, and nothing else.