I just watched this film for the first time on cable channel TCM (US). I had never heard of it.
The presence of Ray Milland is a plus, and I found Anthony Newley quite amusing though the runaway toy flying saucer scene is perhaps just too goofy.
Any effort to develop the story or characters is somewhat half-hearted. What little plot there is seems to exist mainly to fill time between the flying sequences. But what great sequences they are! The formation flying is impressive, the aerial photography very well done, helped along by some beautiful writing by the film composer, and the planes are just great to look at.
Over on this side of the pond we haven't had much chance to see these British aircraft. I don't know if there was any jet in the 1950's more beautiful then the Hawker Hunter. This plane is featured in the latter stages of the film. At the end, Ray Milland guides a wounded plane down to a belly landing. On the way, there is impressive camera work that follows these two planes bounce along in the air, just above the countryside.