Missing man formation
Alternate reality
The missing man formation was a ceremonial maneuver performed by Starfleet pilots saluting a fallen comrade. During this maneuver, four aircraft flying in a V-shape formation make a low-attitude pass over a memorial event. One of the aircraft will separate from the formation, signifying the passing of the soul into heaven.
In 2260, this formation was performed over Starfleet Headquarters in San Francisco, during the memorial honoring those who were killed in the previous year by Khan. (Star Trek Into Darkness)
From the Star Trek Encyclopedia, 4th ed., vol. 2, p. 47, "The missing man formation was performed in the skies above Los Angeles on 1 November 1991 for the memorial service honoring Gene Roddenberry. A musician played "Amazing Grace" on bagpipes while we all watched respectfully as four beautiful planes, Beechcraft Starships, flew overhead until one peeled away and soared into the distance, saluting Star Trek's creator."