Umm, first of all Skywest's F-100 is FWI. It is doing three runs a week Perth to Argyle primarliy, so any flight over Port Hedland shouldn't have anything to do with Skywest (on that run at least).
From what I have heard Skywest are leasing it from Alliance. A couple of flight attendants from Skywest have been trained on it but the majority of flight attendants are from Alliance. The pilots are Alliance. Skywest are using Alliance's AOC (therefore making it a cross-charter type setup) and Alliance engineers are training the Skywest engineers so that the maintenance can be done in-house at Skywest.
Hope I haven't offended or upset anyone.
Ref