波音737-800飞机起飞性能随襟翼放出量的变化特点

Characteristics of the Takeoff Performance Variations of B737- 800 Airplane with the Flap Deflection

波音737飞机与其他民用机型的一个不同之处是前缘缝翼在起飞时可以使用开缝状态。分析了波音737-800飞机下列四个起飞性能参数与襟翼放出量的关系:场地长度限制的最大起飞重量;爬升梯度限制的最大起飞重量;障碍物限制的最大起飞重量;起飞决断速度。结果显示这四个参数在襟翼放出量为10时出现异常,原因是前缘缝翼状态发生了变化。在襟翼放出量由5增大到10的过程中,前缘缝翼由不开缝的放出状态变成开缝的完全放出状态,降低了升力系数。

One characteristic of B737 airplane is that the slotted extension state of the leading edge slats can be ap-plied in the takeoff, while other types of airplanes do not apply this state in the takeoff. In this paper, the relation-ships between the flap deflection and the following four parameters of the takeoff were analyzed：the maximum takeoff weight limited by field length, the maximum takeoff weight limited by climb gradient, the maximum takeoff weight limited by obstacles and the takeoff decision speed. The results show that these four parameters of takeoff are abnor-mal when the flap deflection is 10. The reason is that the extension state of the leading edge slats is changed. During the increase of the flap deflection from 5 to 10, the extension state of the leading edge slats is changed from the sealed extension state to the slotted extension state, and such a change of state causes a decrease of the lift coefficient.