Heathrow Trials: A Briefing from HACAN

Heathrow Airport is to be given more freedom to land aircraft on both runways at the same time.

The plan is included in the report of the South East Airports Task Force published in early July. The task force, chaired by aviation minister Theresa Villiers, was set up by the current government when it came to power last year to look at ways of improving the efficiency of Heathrow. The report says that delays will be reduced if BAA is allowed more flexibility in using the runways. The new practice is going to trialled for a period. If it is decided to continue with it, the proposal would go out to public consultation.

The commitment is still there to retain runway alternation but these plans would eat into it. At present BAA is permitted to operate flights out of alternation in emergencies and at times of severe congestion. It means about a dozen flights a day may be out of alternation (the figures for May 2011). What is being proposed is to extend this to allow them to do so to ease less severe congestion. There would, though, be no overall increase in flight numbers over the course of a day.


There will be two trials of the proposals: for four months over the winter (November – February); and for three months in the summer (July — September, including the Olympic period). After each trial period there will be a period of assessment in which the Government will involve residents’ organizations like HACAN.

The 10 Minute Rule

Residents are concerned that the trials may result in a significant number of planes landing on the ‘wrong’ runway following the publication of the criteria for the trials on BAA’s website – Details of the Trials.

The criteria are as follows:

The operational measures will be used once one or more of the following conditions, which have been agreed by the Department for Transport (DfT)and the Civil Aviation Authority (CAA) have been met:

  1. The anticipated arrival delay or departure delay is 10 minutes or more;
  2. The headwind component on approach to Heathrow is forecast to be greater than 20 knots at 3000ft;
  3. The arrival or departure flight schedule is anticipated to run later than 30 minutes or 30% of flights are running outside of the 15 minutes punctuality target;
  4. Following a period of disruption to recover the operation such as snow.

These will be subject to the judgement and discretion of air traffic control.
Since the average delay for planes using Heathrow is currently 12 minutes, the worry is that the half day’s period of peace and quiet afforded by the runway alternation could be eaten into quite noticeably.

Although the biggest impact is expected on those areas which benefit from runway alternation when planers are landing, areas under the take—off flight paths could also experienced periods of the day when the number of aircraft increases.
BAA argues that the greater flexibility it would have during the day might result in fewer flights taking off after 11pm at night.