The U.S. Air Force has begun replacing its dwindling supply of QF-4 target drones with QF-16s, according to a March 9 Boeing announcement.

With the supply of venerable F-4 airframes running low after years of use as target drones, the air service has given Boeing a $69 million contract to convert up to 126 of the service's oldest F-16s in storage at Davis Monthan Air Force Base, Ariz., into aerial targets, according to the announcement.

Design work on the drones will be done at Boeing's St. Louis facility while production will be done in Jacksonville, Fla.