<human>:  How many engines does the presidential plane, ‘Air Force One’, have?
<bot>: Air Force One is a Boeing 747-200B, which has four Rolls-Royce RB211 turbofan engines. The RB211 is a high-bypass turbofan engine that produces thrust through a bypass ratio of 30:1. The engine is capable of producing up to 58,000 pounds of thrust.