Don't forget that the Aircraft at EDI, NCL, BFS do the Royal Mail night time contacts ... so in reality they may have quite a lot of slack during the day but at night they are shuttling up and down the country! I wouldnt mind betting that a Jet2 737 at say NCL will do more rotations in 24 hours than say a Monarch A320!
Maybe Mr Brown forgot that the Jet2 birds make money during the night aswell as the day!
Jet2 also have an extensive charter operation! Charter flights this week:
DUB-VRN-DUB
MAN-AYT-MAN
LGW-KGS-LGW
LGW-FUE-LGW
MAN-DLM-MAN
MAN-REU-MAN
STN-FAO-STN
MAN-MLA-MAN
STN-PMI-STN
STN-MAH-STN
STN-LDE-STN
LBA-VRN-LBA
STN-VAR-STN
STN-SKG-STN
EDI-VLC-LTN
STN-FAO-STN
Remeber Jet2 sell no seats on these flights at all, the charter operations grows during the winter. So actualy, Jet2's aircraft sit on the ground a lot less than you may think!