Citation Hemisphere in flight
The Hemisphere program is on track, and Textron has opened the order book for its entry into the large-cabin market.

Textron Aviation's Hemisphere Order Book Officially Open

Textron Aviation is opening the order book for its $35 million Hemisphere, which will sit atop the product line as the company steps into the large-cabin market. The airframer has brought a mockup to this week's National Business Aviation Association convention in Las Vegas, to showcase the three-zone cabin that will be fitted within a 102-inch-wide fuselage that is 43 feet long from the aft end of the cockpit to the pressure bulkhead on the back side of the in-flight-accessible baggage compartment. The company has developed various options for the interior to demonstrate the flexibility of the aircraft, said Rob Scholl, senior vice president, sales and marketing.

The 4,500-nautical-mile, Mach 0.90 aircraft is attracting interest from across the board, Scholl said, from corporate operators and fleet owners to individual operators. “We’re really excited about the great feedback we’re getting…as we continue to work with the customer advisory board,” he said.

The order book opens as Textron Aviation engineers start to move off the Longitude program—which is approaching certification in upcoming months—onto the Hemisphere. The company recently wrapped up wind tunnel testing in Cologne, Germany for the aircraft, said Brad Thress, senior vice president of engineering. “Now we are going to proceed on to piling people into architecting, sizing structure, and starting to design structure.”

The Hemisphere is the first of the Citation program to use a High Reynolds Number wind-tunnel test. “Particularly of interest to us is accurate co-efficient of lift in landing configuration and ground effect," Thress noted, adding that those measurements can be elusive. “We really wanted to make sure they were right.”

Textron Aviation used a 6 percent scale model—a little larger than the one used for high- and low-speed tests—that was made of special alloy to withstand temperatures as low as -261 degrees F and pressurization to almost five atmospheres, “a huge amount of energy,” Thress said. “This is a really cool tool. It’s the first time we’ve ever used it, and we learned a lot from it. This gives us what we call final iterations of our loads.”

That data is being distilled as the program moves into the next stage of development, Thress said. “The Hemisphere is on track.”

During last year’s NBAA convention, Textron Aviation announced that 12,000-pound-thrust Safran Silvercrest engines would power the twinjet and that Honeywell would supply its Primus Epic avionics suite. In addition, the fly-by-wire aircraft will incorporate active-control sidesticks.

Plans are for first flight in 2019 with certification following a year later.