Was having a chat with a fellow pilot a couple weeks ago about Pilatus PC-12's. It seems to be an overall impressive aircraft with impressive economics. The PT-6 powerplant is one of the most reliable and proven engines, and the aircraft operates on behalf of some serious organizations in some very demanding roles in unforgiving environments(Royal Canadian Mounted Police operates them in the Arctic, Royal Doctor's Flying Service operates them in the outback of Austalia, etc.) Pilatus continually points out that PT-6 powerplant failures are pretty much unheard of and that the engine-out glide characteristics should leave a pilot with a few options up his sleeve if it should happen.
Yet after my conversation with my colleague, and after reading the following articleon AvWeb, I've been pondering this issue:
PC-12 With "Engine Problems" Goes Down Downtown
Approximately 7,000 feet and seven miles out of South Bend (Indiana) Regional Airport a PC-12/45 reportedly lost power from its generally uber-reliable PT-6 powerplant and landed safely (excepting wing-to-power-line contact) on a busy store-lined road. The wing lost its battle (leaving an outboard section plus what the local fire marshal estimated at "400 gallons" of fuel on the road), but the occupants, aircraft and passersby escaped victorious ... provided victorious means physically unharmed. The quarter-mile stretch of road-turned-runway was actually Route 933 north of Douglas Road. Again, none among the two-man crew, three passengers, pedestrians or drivers was injured, leaving many enthusiastic witnesses. "It was skidding and jumping and then it hit a pole. I heard the brakes skid," Aaron Bolin, told the South Bend Tribune. Bolin watched the episode from the relative and highly precarious safety of a nearby gas station. "He told me he got it over an intersection and dove it under some power lines," Miers' father told the Tribune. "He dropped it down in an area that was just full of light poles, electric poles and business," said another witness. One of the aircraft's passengers summed things up thusly, "We're happy to be alive."
The 25-year-old pilot reported "engine problems" and announced his intention to attempt a return to the airport for landing. That part of the plan didn't work out, as residents of 600 local homes lost power due to the Pilatus / power line strike -- still likely a preferred outcome. The aircraft was temporarily moved to the Howard Johnson's Inn parking lot near where it stopped ... traffic was tied up for several hours.
As my colleague pointed out, the real weakness isn't the PT-6 powerplant, but rather the High Pressure (Engine Driven) Fuel Pump (of which the PC-12 only has one). Lose the HP Fuel Pump= loss of the engine. The low-pressure boost pump does not even approach the pressure required to keep the engine running. I'm not an engineer, but could Pilatus or Pratt & Whitney have designed redundancy into this system by providing for two HP Fuel Pumps?
This is the second PC-12 power loss accident that I am aware of-- the other one occured a few years ago in Newfoundland, Canada, to one owned and operated by V Kelner Airways (who ironically is the Pilatus dealer in Canada).
Any thoughts?
