Story ID: 040
Hands On: SkyCourier Lab Simulator
By: Matt Thurber
Caption: A flying session in Textron Aviation's SkyCourier lab simulator revealed interesting characteristics of this heavy-duty load-hauler.
Word Count: 1342
Textron Aviation test pilots are busy flying the final hours in the SkyCourier 408 utility twin-turboprop certification program, so it’s difficult to pull one aside for demo flights. But recently I was invited to fly the SkyCourier “iron bird” simulator at Textron Aviation’s top-secret laboratory, which is hidden in a corner of its massive campus in Wichita. Although not a full flight simulator with motion, it nevertheless gave me a good feel for what flying the SkyCourier will be like for pilots hauling cargo and a cabin full of passengers. Plans call for certification and first delivery by the end of this year.
Test pilot Aaron Tobias briefed me on some of the details of the SkyCourier. When I saw the real airplane for the first time at EAA AirVenture Oshkosh in July, I was surprised at its size—much bigger than I'd expected. But that makes sense for a twin-engine utility turboprop that can carry three standard LD3 freight containers, loaded through a massive cargo door on the left rear of the square-shaped cabin. The door measures 87 inches wide by 69 inches high. Pilots still have their own separate access to the flight deck through forward-fuselage crew entry doors. And in passenger configuration, the fuselage is fitted with windows—unlike the windowless cargo version—as well as a stairway entry under the left wing.The SkyCourier's cargo door measures 87 inches wide by 69 inches high and the cabin can accommodate three LD3-size containers. (Photo: Matt Thurber/AIN)
There is no comparison between the SkyCourier and other airplanes because nothing is available that matches its size and capability; this is not a Twin Otter competitor. The wingspan alone is 72 feet, nine feet longer than the Twin Otter. Maximum takeoff weight is 19,000 pounds, much heavier than the standard Twin Otter’s 12,500, and the SkyCourier’s cargo payload is 6,000 pounds or 5,000 pounds in the 19-passenger configuration. Takeoff field length is 3,300 feet. With a 5,000-pound payload, range is 400 nm.
The strut-braced wings, which connect to a beefy mount for the fixed landing gear, are not the most aerodynamic design possible, but simplicity is a SkyCourier feature. Operators want a utility airplane that doesn’t need a lot of maintenance, and on this front, the SkyCourier delivers. Maximum cruise speed is 200 knots and maximum range 900 nm (at 10,000 feet and long-range cruise speed).The SkyCourier is a large airplane, which was evident during its public debut at EAA AirVenture Oshkosh 2021 in July. (Photo: Matt Thurber/AIN)
Other features that make the unpressurized SkyCourier effective for its roles include single-point refueling, optional air conditioning, and engine fluid level displays on the avionics displays, eliminating the need to climb up to the engines to check the oil.
In keeping with efficiency goals, the avionics are what have become almost a standard for Textron Aviation’s light and utility airplanes and most of its jets: Garmin’s integrated flight deck, in this case G1000 NXi. Unlike cargo airplanes of yore, whose pilots had to hand fly everywhere, SkyCourier pilots get Garmin’s top-of-the-line GFC700 autopilot with Garmin’s electronic stability and protection limit-cueing system. This is a smart move as many new pilots are learning in G1000-equipped airplanes and will be able to make a simpler transition into the SkyCourier. Because of its weight, the SkyCourier pilots will require a type rating.
Starting the SkyCourier’s Pratt & Whitney PT6A-65SC engines, each delivering 1,100 shp, is much easier than starting the engines on a typical turboprop and more like starting a modern jet. Just push the starter toggle, then move the power lever out of cutoff, and the rest is automatic. The engines are not controlled by Fadec, to keep things simple, but thanks to the digital G1000 avionics, the engine instruments display a bug for power settings, including cruise climb and cruise power. “You can give it full smash as long as the gauges are in the green,” Tobias said. “It’s simpler than a King Air.”
When I pushed the throttles forward for takeoff at simulated Wichita Eisenhower National Airport, the SkyCourier picked up speed quickly before lifting off at above 90 knots. Tobias had warned me that the simulator didn’t replicate ground handling well, so I shouldn't be surprised if I couldn’t keep it on the runway during takeoff.
The lab simulator does have electric control loading, so I could feel what the controls should be like for real, although work was still being done to refine that aspect of the simulation. As a so-called “iron bird,” this simulator is connected to actual flight control systems and parts with the same cable runs and autopilot servos, a dimensionally precise replication that allows engineers to wring out system design, software, and components well before first flight, without tying up the flight test SkyCouriers.
Cameras are positioned to record the iron bird and all the components, not only to observe their operation but to refine the human factors aspects of the SkyCourier flight deck. “This is a human factors test article,” Tobias explained. “We’ve been working on the human factors side since this was on the drawing board.” The human factors team has been running pilots through iron bird flights regularly, measuring aspects such as switch positions, control layouts, and more to maximize safety and efficiency. Next door to the iron bird is a control room where engineers monitor all the action. “It’s a very versatile tool,” he said.
I did realize fairly quickly that with conventional mechanical controls and being such a large airplane, the SkyCourier feels somewhat heavy on the controls and it’s important to use trim as needed and not muscles to fly the desired trajectory.
After takeoff, I pulled the power back a bit and flew some turns, climbs, and descents to get a feel for the view through the large windshields and side windows and for how the SkyCourier handled. My impression? It handles well and is easy to fly, has harmonious feel between the aileron and elevator controls, and gives pilots a well-designed flight deck with no surprises. The SkyCourier feels like an honest airplane, nothing fancy, but nevertheless a state-of-the-art design for the mission of carrying cargo pallets, a combination of cargo and passengers, or up to 19 passengers.
I wanted to try out the SkyCourier’s response to engine-out situations, so Tobias pulled power and feathered the right engine. Until I got the trims settled, I did have to use some muscle on the controls, but the airplane reacted well during the engine failure, adding some rudder bias to help manage the asymmetric thrust.
I flew the single-engine approach and landed on Runway 19L. Handling was perfectly normal once I trimmed the rudder, and the SkyCourier was easy to land. Tobias then reset the simulator and gave me back both engines, and I returned for a normal visual approach to Runway 01L. Final-approach speed was in the 90s in my simulator flight, but with a heavy load goes up to below 120 knots at maximum landing weight. The large flat-plate area of the McCauley Blackmac aluminum propellers makes it easy to cut power and slow down quickly for landing.
Although the lab simulator is not the same as a full-motion Level D simulator, flight test pilots use it to get comfortable with the flying and human factors characteristics of the airplane to prepare for the first flight. My impression from the time in the lab simulator is that the SkyCourier is a straightforward airplane perfectly suited to its cargo- and passenger-hauling missions, and pilots who end up flying it will appreciate its performance and capabilities.