Does anyone know the stack (holding) models for the JFK, Schiphol, Heathrow and Dubai airports? I mean, not where the aircraft hold but rather how is it planned and what concepts are used? Or how I can find that data?
Here is a website with some information about the holding points at Heathrow: https://nats.aero/blog/2013/06/infographic-why-do-aircraft-hold-at-heathrow-airport/ But it is really a case of trying different keywords in the search engine that are relevant. Holdings depend on the type of aircraft - due to wake turbulence - as lighter aircraft can not land after bigger aircraft due to violent turbulence that may cause major issues. Another factor is the air traffic in the area. This affects the number of levels the controllers use in the stack. Most holding points have 15 levels - from around 10,000 feet to 26,000 feet missing out 14,000 feet as this is the point where controllers can split the stack so that they have less planes to control at one time - this increases efficiency. As you probably know, aircraft must be 1000 feet apart from one another whilst in the stack or just generally on course. Holding points are split into 4 parts and normally take 4 minutes to complete one loop. Each part of the loop takes 1 minute. So if the pilot has a 8 minute delay he will be told by the controller to go around twice (two four minute loops) before he can be passed over to the approach controller in preparation for landing. This is just the basics of it really so I hope it helps.