LONDON, England -- Air safety experts are investigating how a German passenger plane diverted off its authorized path to come 200 meters (600 feet) from a British holiday airliner.
The captain of a Thomas Cook airlines Boeing 757 was forced to veer out of the way of the Boeing 767 operated by Condor Airlines of Germany. The incident took place 10,000 meters (30,000 feet) above the coast of Canada on June 24.
The Condor captain left his designated route to get near a colleague piloting another Condor plane to take a photo of him on his last operational flight, according to British media reports.
http://edition.cnn.com/2005/WORLD/europe/07/12/germany.plane/index.html
...formation flying...with the consent and knowledge of both pilots.