i agree with Shini, they look like what a "skyhawk" appears to be in the books. They have chain guns and scorpion anti-tank missiles, as a matter of fact one almost kills the Masterchief John-117 in the first book, The Fall of Reach. It was during trials of the new (at the time) Mjolnir armor Mark V, the kind you wear in the first Halo. The Halo 2 armor is an upgraded Mjolnir, the Mark VI version.
The skyhawk attacked John first with chainguns, and when the Chief got out of the way, it passed him, turned around, and fired an anti-tank missile at him. He knew it was locked on, so instead of running, he stood his ground, then using Cortana's timing, stepped aside and slapped the rocket, causing it to fly by him, blowing up a few yards behind him. Which is alot better than on you, especially when you have shields and armor. Still almost killed him. I'm pretty sure the book said he got thrown some distance by the detonation. Should be pretty nasty ingame.