You know, when it comes to aircraft or submarines, there is one important thing: they should fly and swim. Otherwise they will simply kick the bucket.
In my answer to that particular remark, I can give you an illustration. Four years ago, data was published by the IISS publication The Military Balance with regard to so-called flying hours. The average hours were as follows for air forces: 275 for the U.S., 210 for the Canadians, 207 for the British, and 25 for the Russians.