You're Steel Gate's ace pilot now, so the Steel Gate Chief Archaeologist wants you to keep patrol around the dig site and fight off anything that attacks. Report back to him when you're done with your patrol.
Eh? Yer back for another day's work?
Well, alright, here's the keys. We don't need any haulin' today, so just keep an eye out for anything suspicious, okay?
I've hooked her up with some rockets and a machine gun - just in case.