Famous for its aerial photography and the use many actual biplanes from the WW1 period, this film, in addition, has some incredibly well staged and shot miniature scenes.
A 60 foot (18.2m) zeppelin miniature was constructed and filmed in a 240 foot long aircraft hangar. It travelled on a trolley that ran on a cable stretched the length of the hangar. An electric winch system allowed for up and down movement. Chemical clouds were generated from skywriting equipment. On the floor was a miniature version of London.
There are a number of miniature SE5a aircraft miniatures hung on wires as well as the zeppelin bomb spotting gondola.
This whole sequence is tinted blue.
This sequence is very well lit and photographed. The smoke clouds hang realistically and the destruction of the dirigible has a very compelling realism with the truss construction all visible in the conflagration.
An old issue of Modern Mechanics has a story on the making of this sequence.
The second sequence is of a bombing of a German depot using a captured German Gotha bomber. The pyrotechnics are spectacularly forceful and the miniature buildings break up extremely realistically. There is a terrific shot of a miniature truck being blown into the air.
In the final dogfight all the aircraft action is for real except for a mid air collision shot which is a miniature.