I can't remember the name of the level, but it's the one where Mickey highjacks the phantom.
In one of the tunnels, there is a watchtower at one end, and at the far end is a mortar wraith. If you rush the level, and fly in as soon as you can, you can make it to the end of the tunnel where the wraith is, before a brute gets in it. This means that you can get in a wraith that has not had a brute pilot, and will not have the failsafe engaged. I discovered this with my brother, on normal coop. Of course, you can't do anything with it since you have to cross more of the submerged city to continue, but it proves a point. It proves that there's a way to drive the wraiths in ODST without fear of them always exploding as soon as you get out.
It definitely can't be done with every wraith, but if you find the ones that don't load with a pilot in them, you can find a way to pilot them safely.
