I've read the book about Operation Chastise, and one of my earliest models – definitely pre-1974 – was a 1/72 scale Lancaster that I remember Daddy helping me paint the Dam Buster bomb. Anbd not too long ago the boys and I watched a documentary about the mission which included making a replica dam and launching a similar "skipping" weapon.
I'd heard about the iconic 1955 movie, but never seen it, so I picked up a Bluray on Amazon after a YouTube video had clips of the attack scenes alongside corresponding clips from Star Wars, claiming that Lucas ripped off the WW II classic's attack scenes. Here's the problem – the Bluray ended up being Region2, so couldn't play in the movie room. But Grayson was able to upload it to his Plex system and he, Parker and I watched this over the weekend.
It was okay, as 1950's black and white British cinema goes. Lots of shots of three Lancasters flying in formation, over the top acting, and atrocious special effects (AA fire is represented by "tracers" which are pretty obviously deliberate scratches on the film). But the attack scenes didn't call Star Wars to mind at all. Yes, they're aerial attacks, but beyond that there's no obvious connection.
The movie understandably downplays how horribly complicated the "spinning bomb" weapons system was. In fact there's no mention of the "spinning" effect at all – just the difficulty of getting the weapon to skip correctly. The spinning, I knew from the book, was the key to the weapon's effectiveness because it would cause a bomb that hit the dam to stay in contact with it as it sank, thus directing the force of the impact against the dam rather than allowing the water to cushion the dam from the blast's effects.
But the movie does show dramatically just how low the bombers had to fly for the system to work. Watching the bombers used in the movie skimming the water at just 60' during broad daylight made it clear just how dangerous the final run was in the dark, under fire.
Overall, glad we saw it, but it's an unavoidable oversimplification – not unlike Apollo 13 – of just how difficult a problem the operation actually was to accomplish.