This is essential usefull if you try Flame Leviathan hardmode.
Explained Version:
If you are assigned to destroy the Flame Leviathans turrets make sure you bind you "Exit Vehicle" key (there wont be a button to klick).
As soon as all 2 (10 man) / 4 (25 man) turrets are down, press you access vehicle button to jump off him.
This saves you alot of time, you are not shot in the air and gliding down and you avoid the problem of beeing shot over the barrier (and thus be inable to act).
Make sure you explain this to you other raid members to, your Choppers have to pick you up right at Flame Leviathan, First Aid you and you Demloisher should be nearby to.
If everything is done perfectly you'll have ~20 seconds where you can help damaging the Flame Leviathan (and the Demolishers are the main damage) while stunnes instead of flying around in the air.
Do NOT try to jump into you Demolisher directly and skiü the Choppers - you will die to the turrets later (Everytime you shoot yourself up you'll receive some damage).
You may only do this after the last stun phase you plan to do.
Short Version:
1. Bind you "Exit Vehicle" key
2. Destroy the Flame Leviathans turrets
3. Jump off him via Exit Vehicle
4. Have you Choppers pick you up immediatly, get a heal.
5. Jump into you Demolisher and nuke him!