Aom tells very instrument pilot under what visibility ( in terms of runway visual range ( rvr ) ) and or cloud ceiling can the aircraft take off , and under what visibility ( again in terms of rvr ) and visual reference can the aircraft continue the approach to land from the decision altitude ( for precision approaches , e . g . instrument landing system ( ils ) ) or from the minimum descent altitude ( for non - precision approaches ) . there are a number of factors affecting the values of aom 机场最低飞行条件让每名按仪表驾驶的飞行员知道，航空器在什么能见度以跑道能见距离来说及或云幕高度下才可起飞；以及航空器在什么能见度以跑道能见距离来说及目视基准下，才可从决断高度用于如使用仪表著陆系统的精确进场或最低下降高度用于非精确进场继续进场著陆。
The main performance parameters of 2 - d ex - internal compression supersonic inlet have been calculated by means of the numerical simulation method , then the relations of these parameters and some factors , such as flight condition , geometric configuration parameters have been analyzed and summarized in this paper 本文通过数值模拟二元混压式超声速进气道的流场，计算并分析了飞行条件、几何结构等因素对进气道主要性能参数的影响，总结归纳了它们之间规律性的关系，研究了超曲面拟合方法。
There are great differences between ground test of a flight vehicle ' s aerodynamics and that of a dual - mode scramjet when ground test facilities are used to do experiments on a dual - mode scramjet engine , the components of incoming flow and its parameters , including total pressure , total temperature ( or total enthalpy ) and velocity must be simulated . at the same time , since the fuel ' s resident time within a combustor is very short , on the order of one millisecond , it is difficult to measure the flow - fields 进行双模态冲压发动机地面试验研究时，必须要求试验设备能模拟实际飞行条件下来流气体的组分、总压、总温(或总焓)以及来流气体的流动速度；同时由于燃料在燃烧室内驻留的时间很短，一般为毫秒量级，从而使流场物理量的测定显得非常困难。
