The crew of the Zeppelin use feet, pounds and mph, whereas being German they would use metric measures, metres, kilograms and kph (or perhaps knots).
When handing LZ36 over to the army, Professor Altschul says, "She is our child, please treat her so." Unlike seagoing ships, German airships were referred to as male.
When showing Richter-Douglas around the airship, Erika Altschul tells him that the occupants of the observation capsule can communicate with their crew-mates by telephone. However no telephone cable is connected to the capsule.
When the british fighters catch on fire, it is clearly shown that the smoke is coming from the wheel assemblies instead of the fuselage, indicating that special effects smoke devices were used.
The German troops attempting to steal the Magna Carta are wearing M1916 Stahlhelme (steel helmets) in 1915. In actual fact, the first helmets were issued to the troops in early 1916, during the fighting at Verdun.
The British aircraft pursuing the airship include SE5's, which entered service in March 1917, although the movie is set in September 1915.
Near the beginning of the film a critic of the war complains about British losses "on the Somme", a battle which was not fought
until 1916.
Mustard gas, as supposedly carried aboard the airship, was not used until 1917. However it was invented in 1830 and refined for use in 1886 and later still in 1913 so it place on the Zeppelin is not an anachronism.
One primary goal of the mission is to destroy "the" Magna Carta, thus demoralizing the British people. However, unlike the U.S. Constitution, the Magna Carta is not a single document but a series of nearly identical charters issued by royal seal. There were 11 "originals," each considered equally original, issued in 1215, of which 4 still survive. There were additional "exemplifications" issued under royal seal throughout the 13th Century, of which 20 more also survive. The destruction of a single version would, therefore, fail to accomplish the German mission of destroying the document.
When Richter-Douglas boards the airship, Erika Altschul is extremely concerned as she claims that the weight of one extra passenger will affect the handling and performance of the airship. This was not the case, as zeppelins were designed to carry large payloads, normally several tons of bombs.