Flights from Heathrow Airport will be disrupted to ensure silence during the Queen’s coffin procession.
The airport confirmed that some flights will be delayed between 1.30pm and 3.40pm on Wednesday.
The Queen will leave Buckingham Palace for the final time ahead of lying in state at Westminster Hall.
Tens of thousands of people are expected to queue to pay their final respects to the late monarch.
Her Majesty will rest at Westminster for four days, with 24-hour public access to the hall, until her funeral on September 19.
The procession is scheduled to leave the palace at 2.22pm and is expected to arrive at Westminster Hall at 3pm.
A service lasting around 20 minutes will be led by the Archbishop of Canterbury, accompanied by the Dean of Westminster.
Heathrow Airport has stated that airlines will notify passengers directly of any flight changes on Wednesday.
The airport also indicated that it anticipates further changes to its operation on the day of the Queen’s funeral.
In a statement, Heathrow Airport said: “Out of respect for the period of mourning following the passing of Her Majesty The Queen, some flights between 1.30pm – 3.40pm on Wednesday, September 14 will be disrupted to ensure silence during the ceremonial procession.
“Airlines will notify passengers directly of any flight changes.
“We anticipate further changes to the Heathrow operation on Monday, September 19, when Her Majesty’s funeral is due to take place. We will communicate more details over the coming days.
“We apologise for the disruption caused, as we work to limit the impact on the upcoming events.”