From Longman Dictionary of Contemporary Englishin formationin formationPMARRANGE A GROUP OF THINGS OR PEOPLEif a group of planes, ships, soldiers etc are moving in formation, they are flying, marching etc in a particular order or pattern a squadron of aircraft, flying in formation → formation
Examples from the Corpus
in formation• The planes traveled 30 feet off the ground, flying in formation. 