Possible mixed mode operations at Heathrow are still being assessed and will be the subject of consultation next year. This will report on the noise and local air quality implications, with particular regard to the limits set out in the Air Transport White Paper. Other impacts, including CO2, will also be taken into account in the appraisal.
The Government have announced night-flight restrictions running until 2012. Further consultation is expected in due course on controls to apply from 2012. Introduction of mixed mode operation does not, of itself, imply any changes to night-flight restrictions.