title: Rolls-Royce RB529 Contrafan
text: # Rolls-Royce RB529 Contrafan
  
  The Rolls-Royce RB529 Contrafan was a high-thrust aircraft engine proposed by Rolls-Royce in the 1980s to power long-range wide-body airliners.
  
  ## Development and design
  
  The Contrafan was designed to power the four-engine Boeing 747 at a cruise speed of Mach 0.9. Like the General Electric Unducted Fan (UDF), the RB529 would have direct-drive contra-rotating fans in pusher configuration, and it would have variable pitch fan blades that were capable of reverse thrust. But a cowl would surround the fans of the engine, unlike the UDF.
  
  The RB529 would have an engine core that was similar in size to the Rolls-Royce RB211-535E4, a 40,100-pound-force thrust (178 kN; 18,200 kgf) turbofan engine that was used to power the Boeing 757 narrow-body airliner.
  
  ## Specifications
  
  Data from Flight International, 6 September 1986, pp. 3-4
  
  **General characteristics**
  
  * Type: Contra-rotating, pusher configuration ducted fan
  * Length:
  * Diameter: 140 in (3.6 m)
  * Dry weight:
  
  **Components**
  
  * Compressor:
  
  **Performance**
  
  * Maximum thrust: 270 kN (27,000 kgf; 60,000 lbf)
  * Bypass ratio: 15.6
  