The PC-12 has a far lower probability of failure than any single engine made. A low time pilot has a very high probability of killing himself (herself) despite a perfectly flyable aircraft after the fact due to inappropriate management of the situation. And engine failure in a twin is everybit the emergency in a single, you are landing...now.
A twin (fact) has 4 times the risk of engine failure than a single engine PC-12...
Why?
A Twin turbine has to use the smallest engine possible running at the highest power close to its maximum thermo dynamic rating in order to offset the inefficiency of having TWO engines.
Due to the lower power required of the motor it is highly likely that you will get 15,000 hours out of the engine without any significant replacement costs aside from your hot section inspection costs. Cruising at LRC up to LRC +15kt range will insure the lowest turbine creep unit rate and virtually eliminate machining of the turbine ring during hot sections. Fuel flow at this range is around 240-260lbs an hour fuel burn depending on temperature.
The PC-12 in contrast uses an engine rated at 1600hp, it is rated to run at 1200 hp for take-off and 1000hp at maximum continuous. However, if you operate a PC-12 taking into account fuel/time/cost etc you find that the actual power setting is around 800hp or 1/2 the engines power rating. This nets a TAS of around 240-250kts and double the range of any turbine twin.
The PC-12 to date has the lowest failure rate of any turbine built, when I last checked there have been 2 documented failures, both were low time aircraft.
The other issues revolving around the engine were not failures but failures to follow procedures to maintain power sufficient to continue flight.
With a PC-12 using "ETOPS" type flight planning insures that you are always within glide range of a suitable airport. With a 20:1 glide ratio a twin engine will be on the ground after an engine failure before a PC-12 lands with its one engine out. In other words, you will not be cruising in the mid teens, instead most flights east will be at FL280-300, westbound mid to low 20's depending on winds. It's a high altitude airplane unlike most twins that cruise in the mid teens to low 20's to get maximum IAS.
When you factor in range, cabin noise, comfort and utility the PC-12 is a tough airplane to beat with the lowest direct operating cost per hour, the savings alone depending on utilization will make the airframe payment vs an aircraft 1/3 its purchase price with two engines.
What you save on the upfront purchase price on a twin is lost in the costs with two engines, more than double the fuel consumption, reduced range, increased cycles, and higher avionics costs to maintain obsolete systems.
Flight plan a non-stop flight from Seattle to Miami in a PC-12 wtih FLL as the alternate. Then do the same in the Turbo-Commode...you can't.
Last edited by Deltabravowhiskey; 13th Mar 2011 at 11:20.