I'm also from Brisbane!
There were 25 episodes in all of this show (12 in Series 1 and 13 in Series 2). I'm still trying to chase down a copy of the first episode but have the other 24. The first series cover the learning stage of the air war (1915)with experiments in mounting machine guns, the beginning of tactical development etc. In the second series the development was progressing and it was all getting more dangerous - not because of the unreliable or ill-designed machines they were flying but because machine guns were being mounted and used effectively. Through this series the class issue was examined more and in fact they always covered a lot of side issues well. I don't think the second series was that bad at all. It is obvious that a third series was planned or at least thought about but it finished in a reasonable way. The quality was such that I was just wishing for more!
For me it captures not only the flying but also the time period so ER well. That's its real charm.