Cessna reports that the fleet of Citation Jets is passing the 30 million flight hour mark.

More than 6,600 Citations have been delivered to customers around the world since the first Cessna Citation business jet was put into service more than 42 years ago.

Cessna recently celebrated a number of milestones, including the certification of the Citation Sovereign+ and the Citation M2 in December of 2013, the delivery of the 400th CJ3 in March 2013 and delivery of the 400th Citation Mustang (pictured above) in January 2012. The first Citation flew in 1969, gained type certification in late 1971, and entered service in 1972.