For a long-range four-jet aircraft in cruising flight, the optimum altitude and the lock-on altitude increase. The most cost-effective flight plan will consist of choosing cruising levels which increase during the flight in order to fly:
发布于 2021-02-09 13:29:45
【单选题】 A about the lock-on altitude B between the lock-on altitude and the optimum altitude C just below the optimum altitude D about the optimum altitude
