From what have seen of the chaps.
1. High tolerance of bordom
2. Sick sense of humour.
3. Healthy consumtion of a wee dram.
4. Have a very broad knowledge of everything aviation
5. And an ability to lie when dishing out weights for doing M&B calcs when flying singles. Mind you most exmainers have this ability when a suggestion of not taking full tanks is made.
MJ