N541PA Lear Jet Pheonix Air (Prestwick 13-11-04).
Normally I have little interest in shoot bizjet types but when I saw this one taxiing along for departure I grabbed my camera and got ready for it.
It is owned by Pheonix Air who have a number of Lear Jet's converted to fire rockets for Fighter aircraft to shoot down in training excercises hence the Military style grey colour scheme it has.
First time I have seen one of these drones and in the UK this job is often done by Falcon 20's of FR Aviation.