BAA is to ask the government to call in an independent assessor to monitor noise and pollution should expansion at Heathrow airport be approved. In a move to pacify protestors against a third runway, the airport operator says that it will only raise the number of flights to within the environmental limits set by the assessor. It also promises only to increase the number of flights using its two existing runways, mixed mode, at peak times when punctuality and reliability “to a standard developed with airlines, passengers and business groups” has been established.

BAA says this method will reduce the environmental impact of stacking in the sky prior to landing and queuing on taxiways before takeoff. BAA chief executive Colin Matthews said: “We have listened to the many arguments around expansion at Heathrow. Although the economic case remains compelling, we understand that we can only increase the number of flights if we can safeguard levels of noise and air quality.

“By calling on an independent assessor to scrutinise the airport’s performance against these limits, we are providing an uncompromising assurance that we will operate Heathrow Airport within the limits laid down by Government.  If we don’t, the number of flights in and out of Heathrow could be capped." He added: “We are also announcing today that we would take advantage of mixed mode to increase the number of flights in and out of Heathrow at peak times only when punctuality has improved to an agreed standard. Today, Heathrow operates at 99.7% capacity, reducing resilience when problems arise. The extra flexibility offered by mixed-mode and the third runway will enable Heathrow to match the reliability of its international competitors.”

BAA says that if the government allow the introduction of mixed-mode and a third runway, Heathrow will establish punctuality targets, based on discussions with airlines, passenger groups and business organisations while also consulting with local people.