From the Daily Mail:
Heathrow flights delayed to 'ensure silence' during coffin procession today
Heathrow Airport flights will be delayed so they do not disturb the Queen's coffin procession today.
The west London airport said in a statement that 'out of respect' for the mourning period it will be making 'appropriate alterations to our operation'.
These include flights being disrupted between 1.50pm and 3.40pm on Wednesday to 'ensure silence over central London as the ceremonial procession moves from Buckingham Palace to Westminster Hall'.