I have had the following reply to the complaint I placed on the Heathrow site. I still recommend constituents register their own complaints on the Heathrow noise site as well:
” I am sorry you have been disturbed by aircraft using Heathrow. Your complaint has been registered.
The airspace trials ended on the 12 November and flights have now returned to pre-trial patterns.
During the trial your area was affected when the airport is on what is known as ‘westerly operations’ (i.e when there are westerly winds). During periods of westerly operations, planes will land over London and depart towards the west. However since the trial ended, we have mainly been on easterly operations. During these periods your area will see overflight either from planes making their way to the final approach into Heathrow or as they depart on route 6 and head west. This happened prior to the trial. I have attached some slides to show how your area is affected during easterly operations. It also shows the situation prior to the trial starting.
In light of concerns that flights have not returned to pre-trial patterns, we have also carried out some analysis that looks at the numbers and heights of aircraft before and after the trial. This analysis can be found on our website Heathrow.com/noise. “