Well, let me answer you and ZackDark, and simultaneously clear things up for kreativekill who mentioned earlier that he'd forgotten how he did it.

ZackDark, yes that's one way to set things up. You can descend from the level's first bridge, go off and set up a Banshee on one of the twin bridges, or even one on each of the bridges (for extra convenience), then return with another Banshee to resume from the skip.

But it's also possible to do things without using an early bridge descent. You can play through the level as normal and steal the platform Banshee. After the level's first dropship, you can skip over a trigger point - namely the one which would trigger tower troops - and then set up one or two Banshees on the twin bridges. Then return to resume from the skip.

I'll elaborate on these two procedures in an article I plan to start on today. But PerseusSpartacus, there's no problem with using the lift to go down from the first of the twin bridges.

Finally, I believe kreativekill used the second procedure. The reason being, there's a bit in his footage where he encounters a cloaked Elite on the second of the twin bridges. That guy wouldn't have got triggered if things had been set up the first way.