That’s how people in the industry call a kind of aerial salute that usually occurs during a funeral or memorial event dedicated to a fallen or veteran aviator, or some other important figure. This formation calls for a space to be left in the chosen flight formation to signify the absent pilot from the ranks.
In the image we have here (click main photo to enlarge), we see one F-15C Eagle and two F-15E Strike Eagles flying over the RAF Lakenheath base in the United Kingdom, in honor of the Battle of Britain Day – that is celebrated in September, the month when RAF Fighter Command claimed victory over the Luftwaffe.
As per the U.S. Air Force, which just recently released the photo, the F-15C is pulling away from its siblings to create said missing man formation. The three planes together also make for one amazing underbelly shot of modern-day fighter jets flying together.
The F-15 family of planes was born way after the war ended, in the early 1970s. Close to 1,200 of them have been made since, and are presently fielded by the militaries of seven allied countries – the United Kingdom is not among them.