Corrected entry: Joe and Franky jump into their respective aircrafts. We see Franky slide her canopy shut and grin at Joe. We cut to Joe, grinning back at her and sliding his canopy shut as well. Then we cut back to Franky sliding her canopy shut again.
Corrected entry: As Dex pilots the air barge,and the scientists explain Totenkopf's nefarious scheme, Joe has the solution in his possession - the ray gun developed by Dex that melts metal. All he had to do was burn a hole in any portion of the space craft, and it would have failed at lift off.
Correction: True, but doing so might have been fatal to our heroes. There's no telling whether or not the ray gun would ignite the rocket's fuel source. When you take into account that Totenkopff meant to use his rocket to ignite the Earth's atmosphere and wipe out all life, it's better to be safe than sorry.
Corrected entry: When Gwyneth and Jude had to get new clothes at the monastery, Gwyneth has no lipstick on. In the plane later, she has on lipstick. If her bag was destroyed in the explosion, where did she get lipstick in the middle of a tundra? And where did Jude get another bomber jacket if they destroyed his clothes due to the uranium poisoning?
Correction: She wasn't allowed to take any clothes on the trek through the mountains. But she left her skirt and heels and such at the camp, where she most likely left her lipstick.
Corrected entry: They talk of the 1914-1918 war as the First World War. It was known as the Great War until WWII.
Correction: History seems to be different in this movie. It's possible that the second world war is going on during this movie or has already happened before it. At one point in the movie somebody mentions that the last notes by Totenkopf were "written in 1918, over twenty years ago". The key word being "over". Also, the Hindenburg III docks with the Empire State Building in the beginning, which it was actually designed for except it never happened because of the high winds. The original Hindenburg was destroyed in 1937. So another would have had to have been built and either lost, destroyed or retired and then a third built. This would take some time. There's also a wreck underwater that I believe is supposed to be the Titanic and it's in one piece. They seem to have created their own history loosely based on our own.
Correction: Another few time-stamps to note are the screening of the Wizard of Oz which was first screened on 1939. I'm not sure how things went during that period, like how many years movies ran for. Wikipedia does mention a re-release in 1949 to re-attempt to cover costs. The second time stamp is vehicle design. The cars featured do not seem to yet feature the ponton style of integrating fenders into the car's body, though it would appear the fenders of this age were already getting rounder and more integral and had lost running boards a la VW Beetle. Again, this isn't too concrete since I don't suppose people threw their cars away the moment the new style came up. The third time-stamp would be the mention of global forces being spread thin and their dependence on the Sky Captains as an established mercenary company. Additionally, fabric rationing also placed women's skirt hemlines just below the knee during the 1940s as worn by Polly. This could perhaps place the movie in the 1940s.
Corrected entry: Polly Perkin's charm bracelet has several pennies attached. The foremost penny shows the Lincoln Memorial. This penny did not replace the wheat penny until 1959. 20 years after this movie "took place". (00:23:45)
Correction: This film "took place" in an alternate fictional timeline where the RAF has a flying aircraft carrier and the aircraft are submersible. Unless you can provide some evidence about when various pennies were taken out of service in this alternate fictional timeline, the mistake is not valid.
Correction: The second canopy being shut is not Franky's, but rather another member of her "Amphibious Squadron." Notice that the pilot shown is absent of an eyepatch.