Del , yes I have googled it. The trial seems to have been produced to minimise go-arounds. It would help if pilots were actually ready as they taxi over the holding point. i once saw a Norwegian 737 sit on the threshold for over two minutes whilst the tower were calling him over and over again He finally woke up, didn't apologise and departed. Luckily it was a slack arrival period and he didn't inconvenience anybody. A number of airlines SOP is for certain actions to be completed as they cross the line ,so they can never be fully ready before they are given line up clearance. if you then throw in that the crew may be under training this further slows the process., and because of this arrivals go on a tour of West Kent.
The criteria for a CDA is to avoid any level flight but the rules don't quantify whether this has been achieved wifh a uniform descent rate. Looking at the arrivals you see some aircraft who seem to have an excessive rate down to about 4000ft and then realise they are low and adjust to a V/S of 200fpm.This usuallly is noticable on base leg and coupled with the Airbus signature whine produces a lot of noise. Perhaps some minimum altitude gates should be introduced as part of the CDA. For instance instead of the current clearance to 4000ft and then 3000ft , make it 5000ft until the traffic is clear of Tunbridge Wells and then descend to 3000ft.
Nats need to remind pilots that they must be fully ready to depart and reinstate the guidance and requirements for a CDA and make the chart companies and airlines aware of it.
The tours of Sussex and Kent to avoid holding are nonsense as to a pilot trying to judge their descent rate you have no idea of how far west or east you are going to be taken and the resulting track miles. It is a blatent way to maniplulate the statistics and fools nobody and wastes time and fuel .
Last edited by tubby linton; 15th Apr 2015 at 12:24.