Sprog m8 dont expect to get many points in a Jet. Its bloody hard as most of the time even if you get a kill on a plane the other pilot will bail out so the best tactic to rack up a few points for jet unlocks is attack vehicles that are already being attacked so as to get the assist points. Also I recommend, as often as possible, to fly close by to any other pilot on your team to minimise a direct attack and maximise your chances of outflanking the enemy. Generally speaking, most of the heat seeker locks come from the ground or helis. So try and get up high to avoid that but take care not to stall, If you stall the quickest solution to get out of it is to slow the engine right down and try to roll the plane untill you feel the controls coming back