A creation of Brian Braddock, aka Britanic, the Midnight Runner was originally the private jet of dr. Moira MacTaggert, in service to Muir Island base. To replace the loss of the personal jet to dr. Macctaggert, later Brian Braddock built a medical twin jet, the Moonlight Flit.
Brian Braddock changed it and transformet in a hypersonic jet that can "traverse the Atlantic ocean in less than 7 minutes". Excalibur and his members used regularly the Midnight Runner.
Along with his hypersonic capabilities, it has an on-board artificial intelligence, a cloaking device, a 'Ridercam' (remote viewing system), hovering parking system, autopilot.
It's powered by two turbofans that can reach Mach 2, and after that the drive system is taken by a Shi'ar tecnology that Britanic installed on the runner, and the jet becomes virtually unremarkable, to a point where the "airspeed records give it up and die".