Jet2.com rules require you to be a member of one of three clubs to get a jumpseat ride:
Jet2.com staff
ATC Staff
CAA inspectorate
If you are not in those groups then there is NO CHANCE of getting access to the pointy end in flight. Having said that if you approach us on the ground then I would say most crews will quite happily let you come and have a look around workload permitting. FAO flights will be on the B757 so the turnarounds are slighty longer but the parking tends to require busses which limits your time on board after arrival.
Hope that helps
Box