One of the hottest airplanes that is the talk at this year’s Oshkosh airshow won’t even be delivered for a couple of years. Textron Aviation’s 10-seater Cessna Denali will be the first turboprop plane that pilots can fly like a jet.
The Denali will rely on a new Advanced Turboprop (ATP) engine developed by GE Aviation that is innovative in a number of ways. Almost one-third of the engine will be 3D printed, and it will come equipped with sensors that will enable GE to create a virtual replica of the engine in the cloud. This digital double will allow engineers to track performance and wear and predict the best time for maintenance. It’s almost like personalized medicine for machines.
Another first among turboprops: The ATP will use nifty technology called full authority digital engine control (FADEC), which reduces the number of levers pilots need to control from three to one, dramatically simplifying the piloting experience. “It’s just goodness all around,” says Brad Thress, senior vice president of engineering at Textron Aviation. GE Reports talked to Thress before the airshow. Here’s a snapshot of our conversation.
GE Reports: The ATP engine is the first new turboprop engine design in three decades. Why did you choose it for the Denali?
Brad Thress: In order for us to develop a high-performance single-engine turboprop that’s best-in-class, it needed to have a larger cabin, more range, high speeds and lower fuel burn. Because of the advanced, yet proven, technologies employed by the ATP engine, we are able to bring customers a reliable aircraft that meets all these goals, while also offering significantly lower direct operating costs than competitive aircraft in this segment.
GER: GE says the ATP design will improve fuel burn by as much as 20 percent, while also increasing the engine power by 10 percent. What about the “jet-like” controls. Do pilots want that?
BT: This is a really big step in the right direction. Customers today in the turboprop category are used to manually controlling all the parameters of the engine, which requires a lot of the pilot’s attention, particularly during takeoff and climb. When you have an engine that employs FADEC, the pilot workload is drastically reduced. It allows you to go from tweaking three knobs throughout the course of a flight to setting a single knob in the detent appropriate for the phase of flight.
GER: How easy is it to fly with FADEC?
BT: I would use the phrase “revolutionary simplicity.” When you turn over control to FADEC, you make flying simpler for the pilot and you also maximize the performance of the airplane. Pilots are typically cautious not to exceed the limitations of the engine. They sneak their way to 95 percent of its potential but almost never take advantage of the full power of the engine. FADEC allows them to fly at 100 percent every single time.
GER: What happens when you go above 100 percent?
BT: Eventually, it’s going to have a deteriorating effect. You will spend more money on maintaining the engine or even cause the engine to fail prematurely. Because FADEC protects the engine, you not only protect your operating costs, but also safety. It’s goodness all around.
GER: GE says the engine is equipped with data-gathering sensors that allow owners to create a virtual replica of the engine in the cloud to monitor its conditions in real time. Is this useful?
BT: I think that we will rely on it heavily in the future.
GER: How closely are you working with GE to integrate the engine with your new plane?
BT: GE has six people permanently located at our factory in Kansas. We interact with them daily. It could be on the engine thrust design, the exhaust path, or it could be on the propeller. There’s a lot of collaboration between the Textron Aviation and GE teams, and I commend GE on their commitment to this program. We’ve never had an engine supplier co-locate so many people with the program and live with us like this.