Photographs have emerged that appear to show two aeroplanes flying in formation as they pass over Liverpool.
The images taken today appear to show the aircraft flying side by side - although it is believed to be an optical illusion as they do not show the difference in altitude.
Data published by flight tracking website Flightradar24 suggests there was 2,000ft of separation between the planes as they flew over Liverpool shortly before 1pm on Wednesday.
The plane on the right of the photographs is believed to be Turkish Airlines flight TK12 from New York to Istanbul, flying at 35,000ft.
It was pictured next to a KLM cargo flight from Miami to Amsterdam, which was at 37,000ft.
Air traffic rules require aircraft to maintain a vertical separation of at least 1,000ft.