The recent war has provided a great deal of experience in the operation of aircraft and ground equipment under a variety of conditions. This paper is an attempt to condense and correlate some of the points noted into a logical sequence. It is not based on statistics and is more in the nature of a selection of problems and impressions about them. Possibly this is an advantage, as it seems doubtful if many logical conclusions could be drawn from a set of completely comprehensive observations, even if these were available.