During the pre-flight, Sgt. Danny "Danny Boy" Daly, the radio operator, conducts a radio-check saying, "Charlie, Victor, Uncle, Tango". He is using the modern NATO Phonetic alphabet. During WWII, he would have used a different phonetic alphabet and said, "Charlie, Victor, Uncle, Tare".
The nose art and insignia of a World War II bomber such as the Memphis Belle would have been painted onto the plane in 1943. When Dennis is talking to his plane during the night sequence, the nose art design is clearly seen to be stretched over the top of the rivets on the plane as it is a vinyl decal, rather than being painted on.
While Derringer is reading out the letters from bereaved families that Harriman has thrust at him, we see footage of B17s being attacked. Many of them have the USAAF roundel with bars, but these were not current at the time the film was set. For example, the Memphis Belle had the simpler USAAF roundel, without the bars.
Army Insignia displayed on bandstand, flaming sword of liberation in blue shield, did not exist in 1943, the time frame of the Memphis Belle's final mission. Per Headquarters US Army Europe: "The insignia was originally approved for the Supreme Headquarters, Allied Expeditionary Forces on 13 Dec 44; redesignated for US Forces, European Theater and background color changed from black to blue on 2 Aug 1945; redesignated for European Command on 23 Jun 47; and redesignated US Army Europe on 7 Nov 52."
Col. Craig Harriman's and Lt.Col. Bruce Derringer's service cap appears to have been created for this movie. The style of the crown is similar to the British Army office cap. The crown of Harriman's and Derringers service cap is smaller than the standard WWII Army officer service cap.
During the scene where Danny pulls out the liquor bottle, and Rascal sneaks up behind him to grab it, for a split-second, you can see Danny grin. Eric Stoltz probably happened to see Sean Astin coming in the reflection on the bottle, and without doubt it looked kind of funny to him.
When the B-17 crash-lands near the beginning of the movie, each propeller on the left wing looses a blade and the two remaining blades are shown pointing down and unbent. When the airplane is shown sliding along and coming to a stop, the propellers have all three blades, but each blade is partially broken off and has been bent back. This is the damage that would be expected in the first shot, especially with the outboard engine.
When the Belle is landing at the end of the mission, and they lower the landing gear, we see the right wheel down and locked in place. When we see them lowering the other landing gear by hand, we see that is is the left wheel that is down and locked.
In Memphis Belle the bomber force is ordered to circle back to the Initial Point when the Primary Target is obscured by smoke or cloud cover. In reality, this would NOT have happened. First, it is VERY hard to have a formation of 300-plus Forts make a 180 degree turn. Second, such a maneuver would alert all flak batteries as to the actual target. Third, such a maneuver would keep the force under fighter attack longer than need be. In actuality, bomber crews were briefed on a primary, a secondary, a tertiary and targets of opportunity. If the primary target was unable to be hit, the primary became the IP to set up on the secondary. If the secondary were unable to be hit, it became the IP for the tertiary, and if that were unable to be hit, the force commander (NOT the pilot of the lead aircraft) would issue an order to go after targets of opportunity. Failing that, the mission would be aborted and the crews would dump their ordnance in either the North Sea or the English Channel. The mission would count toward tour completion, as the crews would have been in combat, and were over enemy territory.
The Norden bombsight is depicted in the film as a simple vector bombsight, with the ground moving past the sight due to the forward motion of the airplane, and the bombardier toggling the bomb release switch when the target moves through the crosshairs. In reality, the Norden bombsight was a tachometric bombsight, which continually tracked and automatically released the bombs when the precomputed bomb release point was reached. The job of the bombardier was to make the adjustments necessary to keep the crosshairs stationary on the target. Any forward motion of the crosshairs relative to the target would indicate an error in the ground speed estimate, which would cause an error in the calculated bomb release point.
In Memphis Belle the bomber force is ordered to circle back to the Initial Point when the Primary Target is obscured by smoke or cloud cover. In reality, this would not have happened. First, it is very hard to have a formation of 300-plus Forts make a 360 degree turn. Second, such a maneuver would alert all flak batteries as to the actual target. Third, such a maneuver would keep the force under fighter attack longer than need be. In actuality, bomber crews were briefed on a primary, a secondary, a tertiary and targets of opportunity. If the primary target was unable to be hit, the primary became the IP to set up on the secondary. If the secondary were unable to be hit, it became the IP for the tertiary, and if that were unable to be hit, the force commander (NOT the pilot of the lead aircraft) would issue an order to go after targets of opportunity. Failing that, the mission would be aborted and the crews would dump their ordnance in either the North Sea or the English Channel. The mission would count toward tour completion, as the crews would have been in combat, and were over enemy territory.
Several times during the mission, two crew members (pilot and co-pilot, bombardier and navigator, the two waist gunners) talk to each other with slightly-raised voices without using the intercom. This would have been impossible in real life. The B-17 was a combat aircraft with no soundproofing insulation. To be heard, one crewman would have to place their mouth next to the ear of the other crewman and shout at the top of their voice in order to be heard over the noise of the engines.
We see what are clearly P-51 Mustangs have to turn back "because they've run out of fuel" long before the bombers have reached their target. In reality the P-51 Mustang used drop tanks, which enabled them to escort the bombers all the way to their target and all the way back with fuel to spare to carry out ground attack duties once the bomber force was over the north sea on it's return journey.
"Interphone Discipline" (the communications used between crew-members on each bomber) was not enforced in the movie. Each crew-member had to scan the sky for fighters and report locations to their colleagues. Idle chatter about girls and non-mission items was forbidden for safety reasons. This rule was noted by two actual WWII B-17 crew-members from the Pima Air and Space Museum in Arizona.
Navigator Phil Lowenthal mistakenly calls out that the Belle is at the 'Rally point' on their arrival near the target. In fact it's actually the 'Initial Point.' The 'Rally point' as the name suggests is where the group flies to after the bombs are dropped to reassemble the formation before heading home.
The A-2 flight jackets the actors wear in the film incorrectly sport the 324th Bomb Squadron insignia patch on the right chest. In reality, squadron insignia were worn on the left chest of the jackets, over the heart. Only group insignia were worn on the right chest, and only in the rare cases that both squadron and group insignia were worn on the same jacket. If just a group insignia patch was worn on a jacket, it was worn on the left chest, as a squadron patch would be.
When all the Airforce Senior Officers are standing on the balcony of the Control Tower, waiting for the bomber, none of the windows are taped up as a precaution against blast as they would have been since 1939.
When Danny is talking to the new Radio Operator from Mother and Country, Danny is a seasoned veteran with 3 stripes up and a rocker. This indicates hes a staff sergeant. The newbie has 3 up and 3 down indicating a master sergeant. This is highly unlikely given the newbies age and time in service. It is not likely that he would be outranking a veteran bomber crewman.
Due to a shortage of aircraft, the B-17s assembled for the film had two sets of marking, one on the right side and one on the left. During the take-off scene, several shots reveal that the bombers have two different names and mascots.