And therein lies the whole problem - the movement cap should be a planning restriction only. As long as aircraft are scheduled to arrive or depart within the window then that should be sufficient. If you occasionally go one or two over the limit due to a few late departures, then so be it.
This new 15 minute window is also plainly absurd. I have sat at the holding point at the end of the busy period for two windows with no aircraft at the holding point to depart after us - so while the 80/hr cap was never in danger of being breached, the 15 minute limitation meant an increased delay of about 20 minutes.
How many times in the last few years has the 80 cap been breached? Not very many I would think is the answer! And that is despite not having a rediculous 15 minute window limitation. Aircraft operations do tend to "clump", and this system just increases the delay for everyone.
While we are at it and saving the world, we also need to change the situation regarding the 5am arrivals. The planners approve 5am arrivals as long as it is on 34L only - so aircraft waste rediculous amounts of fuel carrying reserve fuel to hold til 6am in case they can't land, and end up going around in circles for an hour, resulting in massive delays for the whole airport when it opens up at 6.
Its time we got smart and just said "you must land on 34L unless it becomes operationally unsuitable due to tailwinds, when you may land on the required runway". Less fuel wastage, less pollution, and less congestion, and it provides what aircraft and passengers need - some level of confidence of an on time arrival.
|