Consider an executive jet aircraft, assuming it is powered by two jet engines, each of which can provide a maximum sea level thrust of 6,250 lbs. The thrust produced by the propulsion system depends on the flight altitude and the throttle setting according to
where δt is the throttle setting and ρ is the air density in slug/ft 3 at the flight altitude. The thrust specific fuel consumption rate for the jet engines is 0.69 lb fuel/hr/lb.
(a) What is the maximum available thrust provided by the jet engine when it is operating at a flight altitude of 25,000 ft? What is the fuel flow rate at this operating condition?
(b) What is the thrust provided by the jet engine when it is operating at a flight altitude of 25,000 ft and 70% throttle? What is the fuel flow rate at this operating condition?
(c) Suppose the jet aircraft is in steady level flight at an altitude of 25,000 ft with an airspeed of 520 ft/s. Assuming 70% throttle, what is the power produced by the jet engine?
(d) What is the throttle setting required for the jet engine to produce 9,250 lbs of thrust at an altitude of 25,000 ft? What is the fuel flow rate at this operating condition?