Clappered fan blades of a Pratt & Whitney 4056 engine mounted on a Boeing 747-400, taken during an Airshow.
The Pratt & Whitney 4000 series engine used on the Boeing 747 is the first aero engine type to be fully computerized and monitored and controlled by a FADEC (Full Authority Digital Engine Control).
The PW4000 series engine of the Boeing 747 is also ETOPS (Extended-range Twin Engine Operations) certified up to 180 minutes for other twin engine aircrafts which uses similarly rated engines (ie; Airbus A300/310/330, Boeing 767).
Video of a Boeing 747-400 powered by the PW4056 engine taking off:
Commercial aeroplanes typically burn JetA or Jet A1 fuel.
Jet B is used for enhanced cold weather performance in extremely cold climates.