World War 1: Aviation comes of age is 3 week long course that is intended to take up about three hours a week but I found the optional further reading unmissable and so I had to allow more time.
This also meant that having started the course late I was even later finishing it - it took me about 5 weeks in total and I really enjoyed it. Just shows how flexible the the cours is. It's a free online course from the University of Birmingham’s Centre for War Studies.
The course cover many aspects about the early days of aviation and how it evolved raidly through WW1 bring about the formation of the Royal Flying Core before the war and the Royal Air Force by the end of it.
There's many other intersting courses like this available via the Future Learn website so it's well worth a look.