Subject:
LTMA Inbound Speed Trial
In response to a request from our airline customers, NATS
is implementing an econ descent speed trial into the London TMA with the objective
of reducing inner stack holding for the London airports. This trial started
on the 13th May and run for a period of 6 months. Due to delays in
publication, the AIC for this trial will not be published until the 19th June
2008; however, we were keen to start the trial before this to avoid delaying
the benefits. Hence the procedure has been implemented tactically from the 13th
May 2008.
Modelling and simulations have indicated that
approximately 1 minute of airborne holding can be avoided with an earlier and
consistent application of econ descent speeds. By reducing the speed earlier,
this procedure simply transfers part of the anticipated stack holding delay to
the descent phase, thus reducing fuel burn and aviation related emissions.
Total potential savings for LTMA arrivals are expected to exceed 12,000 tonnes
of fuel per annum.
During normal operations for inbound flights into the LTMA, ATC may
instruct pilots to fly a designated indicated airspeed in the descent of 270
knots within an 80-100nm radius. Level clearances as directed by ATC will not
change and are mandatory. As is current standard operating practice, speed
instructions to individual aircraft may be varied by ATC for the purposes of
traffic separation and sequencing.
London TMA airfields are:
- Luton
- Biggin
Hill
- Gatwick
- London
City
- Heathrow
- Southend
- Cambridge
- Stansted
- Rochester
- Northolt
Feedback on the trial can be provided through the www.customer.nats.co.uk
website.
Regards
Richard
Head of External Safety Relations
Division of Safety