With a fully loaded Koala, i.e. nurse, para medic, all their kit, and enough margin for say, a 200lb patient, you'll be lucky to carry 2 hours of fuel in it. Having said that, that bird loves to fly fast. 46 degrees will knock 20-30 kts off your top end though. Terrible oil cooler design. You'll reach your engine oil temp limit before anything else at those temperatures. OAT showed 55 on the ramp one day!