Olham used to keep this forum updated on changes to the above brilliant resource for digitised reconnaissance photos, trench maps and other maps from WW1, but in his lamented absence I'll take it upon myself to notify you all that the folks there seem to have done some re-organisation. McMaster WW1 Maps
There's a new section called Thematic Maps wherein is a sub-section called 'Aerodromes and Hospitals' in which lie a number of maps showing the position of German aerodromes and hospitals opposite the various allied armies in 1918, which are worth a look. There are many other sub-sections to which I'll not mention but leave you all to explore.
The link above is one way in and provides an interactive sector map for easy navigation. However, if you go in this way: Alternative Access Path
The search facility here now works better so you now stand a better chance of finding a particular feature on a map if you know it's general area. For example, typing 'Proven' will bring up the map below: Proven (with Aerodromes mapped)
Zooming in here you can see even the hanger numbers and layouts for several aerodromes, Abeele, Proven, Poperinghe and La Lovie (the latter, for example, is 6 squares down from the top and 3 squares from the right - to the left of Lovie Chateau)
The site continues to improve and it's a fascinating place to lose a few hours.