Indeed - credibility might be lacking where transparency isn't evident. What raw data is available to the verifiers ? The triggering mechanism seems complex and Heathrow have ducked explaining it to me and have referred me to the NATS air traffic control press office : TJH to Heathrow 13th Jan 2012 I appreciate "ATC is only allowed to use the freedoms for set periods of time, when at least one of the trigger criteria have been satisfied and all safeguards are adhered to " but I am still very unclear as to how this is achieved in practice - particularly as I understand from your more recent document explaining the triggers, that the delay or anticipated delay can involve components of what the Department of Transport call "pre-departure delay" at the originating airport. Are you able to say more about how ATC measure, trend and track this delay and how and who initiates a period of "freedom" and subsequently cancels it ? Regrettably the monthly report is not really informative on this. I could understand how it might work if trigger 1 was based primarily on stack holding delay where tracks of the aggregate holding patterns involving a couple of stacks containing three or four planes are probably sufficient to meet the time trigger. I don't understand how the monitoring incorporating the delays from Eurocontrol restrictions is done. Nor is it clear to me what the methodology is for this aspect to be checked by your "independent verifiers". Extract of response from Flight Evaluation Unit Heathrow to TJH 20th Feb 2012 Regarding your specific enquiry on how ATC measure, trend and track delay in the London TMA and wider EUROCONTROL area we would refer you, in the first instance, to NATS’ press office; Telephone: 01489 615 945 (08.30 – 18.00 Monday to Friday) Fax: 01489 615734 E-mail: press.office@nats.co.uk Website: http://www.nats.co.uk/news/press-office-contacts/. Note from minutes of Heathrow Leadship Group October 2011 “Operational freedom” trials and closer integration of NATS and Heathrow airport in a new “operational efficiency cell” both have the potential to improve resilience. It is important to explain to residents affected by noise that “operational freedoms” will be used responsibly http://www.heathrowairport.com/static/Heathrow/Downloads/PDF/HLG_minutes_Oct2011.pdf

Entire Thread

Topic	Date Posted	Posted By
Heathrow Trial - Changes in Operating Procedures	19/12/11 14:04:00	Tim Henderson
Re:Heathrow Trial - Changes in Operating Procedures	11/01/12 01:14:00	Jim Lawes
Re:Re:Heathrow Trial - Changes in Operating Procedures	11/01/12 08:37:00	Tim Henderson
Re:Re:Re:Heathrow Trial - Changes in Operating Procedures	15/01/12 08:13:00	Nic Doczi
Re:Re:Heathrow Trial - Changes in Operating Procedures	12/01/12 12:18:00	Tim Henderson
CAA Interim Report on Heathrow Trials	22/02/12 09:05:00	Tim Henderson
Re:CAA Interim Report on Heathrow Trials	22/02/12 18:36:00	Dave Robertson
Re:Re:CAA Interim Report on Heathrow Trials	23/02/12 10:33:00	Tim Henderson

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