民机适航取证试飞中ILS基准DDM值获取

Ideal ILS DDM Acquirement in Civil Aircraft Airworthiness Certification Flight Test

描述了民机适航取证试飞中仪表着陆系统(Instrument landing system,ILS)调制深度差(DDM)基准值的获取方法。主要工作包括三个方面:第一,在分析ILS基本原理及其航道位移灵敏度和下滑位移灵敏度相关要求的基础上,推导了ILS基准DDM值的理论计算方法;第二,根据光测和DGPS定位的特点,结合实际工程应用经验,提出了使用二者相结合的方式对试验机进行精确定位的方法,并给出了二者各自的使用条件;第三,结合MA600型飞机适航取证试飞对上述方法进行了应用与验证,证明了该方法的正确性。提出的ILS基准DDM值获取方法,对ILS适航试飞具有重要的参考和应用价值。

A method of Ideal ILS DDM Acquirement in Civil Aircraft Airworthiness Certification Flight Test is described. The main work includes three parts： First, based on the analyses to ILS basic principle and it＇ s course displacement sensitivity and glide slope displacement sensitivity requirements, deduces a theoretical calculation method of ILS DDM calculation; Second, based on the characteristic of photoelectric theodolite and DGPS, the method using photoelectric theodolite combined with DGPS of acquiring the test plane precise position is proposed, and the use restrictions of the two method are given ; Third, the method is proved to be feasible in the MA600 flight test program. A good practical reference and application value to ILS airworthiness certification flight test are presented.