running a 767 cf6 aircraft on eng ground run and tested fire handle due to replacement,forgot to close the fuel cutoff lever and then went for a restart.due to fuel cutoff lever being in the run position before 20% had raw fuel vaporising and streaming out the back. Once lightup occured the fire ball was sucked back around into the fan and up over the wing.
the ground observer was last seen running for his life still trying to tow the aircraft with him by the headset.scary but very comical.no damage done and egt within limits