RAF bombing squadron is tasked with destroying a V-weapon site before it can fire at England. Also the usual romantic subplot, along with another subplot about a squadron leader who is believed dead, but is actually a POW with amnesia.
Lacklustre war film tries to soar, but is saddled with some poor scenes on the ground. When it's actually in the air it gets better. The performances are generally competent but uninspired (Charles Gray's character being the main exception), and the dialogue between McCallum and Neve is so uncomfortably awkward it rivals the Star Wars prequels. On a similar note, the briefing scene is a dead ringer for the same scene in A New Hope, as is much of the final attack. Frank Cordell's music is really the main highlight, along with some nice Mosquito footage. McCallum's ostensible hero doesn't inspire much sympathy, especially when he leaves a wounded man to burn to death in a crashed aircraft.
Though often described as such, this is not a sequel to 633 Squadron, though it does reuse some footage from that film and Operation Crossbow, both of which would be better bets for a night's entertainment. The Mosquitoes used in filming did have the same squadron codes as 633 Squadron, so that footage from that film could be re-used in this low-budget film.
Note: Uncredited and unknowns are listed in as close to order of appearance as I could. Thanks to Koosh and Scott Palmer for helping identify some previously unknown parts!