When shooting departing jets at BFI, I often have a conundrum about the lens to use.  For some of the higher performing aircraft, they get off the ground quickly, so the longest lens is probably going to be best.  However, other types use a lot more of the runway and can rotate a lot closer to some of the places I like to shoot from.  The long prime can be best a lot of the time but, if they run long, I might be too close for the shot.  A Falcon 7X can run a bit longer if it is heavy as a result of the three-engine configuration versus the twins like the Gulfstreams and Globals.  This one did that but, it rotated quite close to me.  I was actually really pleased with how things turned out and then I spun around to get the climb out from a tight angle as well.