The best way that I found to counter a Jet is team power, trust me I have also been in the same scenerio your talking about You can use one of these methods that I found out would be good: 1. Teamwork, no doubt about it teamwork helps but only if your team does listen to you, I highly suggest shotguns while Jet is close enough to the ground if not get a car and distract the Jet user allowing your team to take out the on-foot enemies. 2. Heavy firepower is another great way to defeat a pilot, just get a gun or use grenades that allow you to deal massive damage in the shortest amount of time possible, if you use a rapid fire gun make sure the range and damage are decent enough to do so, you wan't to deal tons of damage knowing when you respawn you can keep firing. Another great thing to keep in mind is the fact that Jets need to recharge missels, so you can deal damage while they recharge at the same time. 3. Getting cover, sounds like something you try, I recommend this tip to maps like T-pile where you can hide for cover and change postition very quickly, if I am at team blue and a red gets the Jet I try to bring them to the front and I change postition to the right side wall. Hopefully that helped you!