nosefirst I did something similar myself about 20 years ago. Paris and Farnborough are sales shows, not recruitment - but you'll meet a lot of engineers on the stands who understand what it is to be job hunting, and will be very sympathetic. If they treate you like they did me, they'll be helpful with advice, contacts, suggestions of how to apply to their particular companies. The other good show for this is Helitech at Duxford.
G