Tagron - thank you for pointing out the cuts that OLT have performed over the winter - I hadn't realised the extent
I've had a look through the schedules, focussing on the first full week of March 2013 - i.e. a period in the winter season when there should be maximum flying while excluding Xmas + Easter
Looking at the published schedules for aircraft based at Dresden, Karlsruhe, Munster and Saarbrucken, fitting all the times together into a schedule using 6 aircraft, I've calculated the average length of time across the week that each aircraft is non-stationary - i.e. block time. I'm also assuming that the FMO-VIE route which is approx 420 nm takes 1h45 and not the published 2h45
Dresden1 - 4h06 per day
Dresden2 - 5h57 per day
Saarbrucken - 7h50 per day
Karlsruhe - 6h06 per day
Munster1 - 6h08 per day
Munster2 - 5h24 per day
I accept that this ignores any charter work or time for maintenance.
First departures for each aircraft seems to be around 0645, with last arrival about 20h45, so about 14h00 per day available for commercial service.
Looking across all 6 aircraft, this means airframe have an average block utilisation time of approx 5h55 per day. For an airline that flies almost entirely city routes and thus is less seasonal compared to beach-centric operators, this looks a little on the low side