What I do know is that many mining businesses in NW WA have requirements for the availability of 24/7 evacuation services, with a contracted minimum response time, which precluded Perth based crews and aircraft.
You're talking about the Karratha-based Aspen Medical contract, which operate Citations. You're not talking about the RFDS. The only way a contract can have "minimum response times" is if the aircraft is dedicated to that particular contract, which is the case for this contract between Aspen and Chevron, Woodside, Santos, Shell, and a few others.
The RFDS aircraft are all available for "public" health use. Contracting a "minimum response time" in this case would be meaningless as the aircraft and crews may be tied up for days doing the "public" work. Irrespective of how much money Rio Tinto may have kicked in, I think you will find there is no such contracted "minimum response times" involving the Pilbara mines. How could such a contractual requirement be worded?
Those Pilbara minesites, by the way, are indeed closer to Broome than Perth, but by only about 35 minutes. Any special deal between the RFDS and Rio Tinto would be about the
medical response, not whether the aircraft is
jet powered. The quickest way to the Pilbara is via the 35 minute PC-12 from Port Hedland, or the 50 minute PC-12 from Meekatharra. The PC-24 from Broome would take about 55 minutes (90 minutes from Perth).
And taking the RFDS rostering and base-standby practices into account, it may be the Perth jet quickest on the scene, anyway. This is because for a large part of the day, some Perth pilots are at the airport, on standby, whereas for the remote bases they are at home and have 30-60 mins (?) to get to the airport.
The "Rio Tinto minesites minimum response times" theory just doesn't add up.
So, what is the point of the Broome basing? What can be achieved other than a bigger medical bill for the taxpayer?
Clinics with accommodation and caring staff, supplied with no tools (or fuel for the genset)
Going to some lengths to make Halls Creek and Fitzroy Crossing sound like backwater communities there, Bend alot. The reality is that those places have substantial hospitals, each with more than a dozen doctors. There is also a St John's Ambulance service in both towns. Any injuries, accidents or illnesses would first go to those hospitals for stabilisation.