Page 6 - Sept 19 TNT

Position Report by Dianne White What Makes a Turboprop Safer? T wo engines or one? If your aircraft is equipped with the highly reliable Pratt & Whitney Canada PT-6 turboprop engine, are you really safer in a twin rather than a single? This perennial debate gets resurrected every time there is a high-profile crash. And we’ve had a few in the last few months that caught our attention. In June, a Cessna 425 Conquest I crashed in Missouri after the pilot reported having a right engine problem on descent through 17,000 feet. After reporting to ATC that the engine was still stuck at full power and he was shutting it down, he requested to divert to the closest airport. While maneuvering to land, the plane crashed into a grain silo in a nearby field, killing the pilot, the sole occupant. Then in July a King Air B350i with 10 on board crashed on takeoff from the Addison, Texas airport, killing all on board. A dramatic surveillance video of the flight’s last few seconds – one I’d like to forget – shows the aircraft in a powerful roll to the left prior to impacting a hangar. According to the NTSB, the two-person crew made comments “consistent with confusion” 12 seconds before the crash, followed by a comment about a left engine problem. As you may know, the 350i is the rare GA turboprop that requires a type rating. There have been several unfortunate single-engine turboprop crashes this summer, too. Some were fatal, and others resulted in injuries. Do the accidents stats provide any clarity? According to an analysis by AOPA, between 2005 and 2014, the majority of the accident turboprops (125, or 57 percent) were twin-engine models, which showed no survival advantage. Lethality was identical at 37 percent in both singles and twins. This leads to the question of pilot competency. Many years ago, when I started my multi-engine rating, the first thing my instructor did was hand me an FAA publication entitled “Flying Twins Safety” and told me to go home and commit its key points to memory. When I started to pen this column, I dug it out to make sure I had the title correct. It, like me, has aged a bit and has a few more wrinkles but no worse for the wear. Flipping it open, the first line of the booklet says, “The major difference between flying a twin and a single-engine airplane is knowing how to manage the f light if one engine loses power.” Thus, we spend much of our time during multi-engine training practicing engine-out scenarios and understanding thrust asymmetry, the critical engine and VMC. Once we set the date of our check ride, our skills are most likely sharp, and we are proficient at every engine failure circumstance. In addition, our senses are heightened, as we are expecting that darn left engine to fail at any moment. What happens over time as that “training muscle” weakens? Do we grow complacent as we always expect the PT6 to perform reliably? Advanced ratings and total logbook time may help, but it’s interesting to note that one-third of the pilots involved in turboprop accidents (twin and single) between 2005 and 2014 held ATP certificates. That leaves us with three important things to consider that have nothing to do with the twin-versus-single debate: Time in type; recency of experience; and our mental “fit to fly” attitude when we climb into the left seat. While mechanical failures in our turbine equipment are thankfully rare, they can and do happen. Are we prepared for when they do? While we are on the subject of “fitness to fly,” I highly recommend you watch an excellent video recently published on YouTube by the AOPA Air Safety Institute titled “Real Pilot Story from the Field: No Go-Around – A lesson from the Backcountry.” Todd Simmons, his brother and two friends recount their backcountry flying trip into the “no-go around” strip of Dewey Moore in Idaho. An experienced pilot, Todd attempted the impossible go-around in his Carbon Cub that ended in a 4 • TWIN & TURBINE / September 2019 PHOTO COURTESY OF CLINT GOFF