Compare that to The Dam Busters:
"How many guns do you think, Trevor?" "I'd say there's about ten guns. Some in the field, some in the tower."
The Dam Busters is about a British squadron tasked with lining up an "impossible shot" to destroy three dams, which you might recognize as the same premise as the Death Star trench run. Lucas went so far as to hire the guy in charge of Busters' special effects photography, Gilbert Taylor, as cinematographer to basically remake some of the old movie's shots. Dam Busters' makeup artist, Stuart Freeborn, also went on to work in Star Wars and create Yoda, Chewbacca, the Ewoks, and other unsightly creatures.
According to Star Wars producer Gary Kurtz, he and Lucas taped The Dam Busters from TV along with many other war movies to "use [them] as guidelines." It's the cinematic equivalent of Frankensteining your homework from Wikipedia paragraphs. At least now we know what's up with all those random British accents.