A Textron Aviation Cessna Citation Longitude rose off the runway at Wichita Dwight D Eisenhower National airport on a blistering hot day in September.

The super-midsize jet climbed swiftly under the power of two Honeywell HTF7700L engines to nearly 45,000ft, at which point Textron executives reviewed why they think Longitude is a winner.

They cited the aircraft's 3,500nm (6,500km) range, Mach 0.84 cruise speed, 726kg (1,600lb) full-fuel payload and quiet cabin.

They also pointed to large windows, an optional 2m (6ft 6in) divan and Garmin G5000 touchscreen avionics in the cockpit.

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Though still uncertificated on the eve of the show, the Longitude is set to become the company's flagship product, especially with development of its sibling, the Hemisphere, on ice. Textron will have two Longitudes on display at NBAA.

"Everything you see about the airplane will make it the new standard in the mid-size class," Textron senior vice-president of sales and marketing Rob Scholl says. "We couldn't be more thrilled about how this airplane is performing."

Launched in 2012, the Longitude will accommodate up to 12 passengers, though Textron says most customers will opt for eight- or nine-passenger configurations. The aircraft has a list price of $26.9 million.

Executives were insisting just before the show that the Longitude's certification was imminent, though the company did not achieve the milestone by September as executives had hoped.

CONFIDENCE

"We feel very confident where this aircraft is, and we are working to [achieve type certification] as soon as possible," Scholl said at a briefing in Wichita in September. "We're close."

That confidence comes despite the Federal Aviation Administration finding that the Longitude's centre fuel tank did not meet some flammability requirements.

However, the FAA granted Textron an exemption from those requirements until January 2020, clearing it to achieve certification and begin deliveries before developing a final fix.

Textron executives have declined to discuss fuel tank issues.

"We feel we have a very good path that's going to have minimal impact on the aircraft and the customers," says Scholl.

Textron is proud of the Longitude, and recently showed off the sprawling, 41,800m2 (450,000ft2) site where workers are assembling the jet using new manufacturing techniques.

Robots are drilling the roughly 10,000 fastener holes in Longitude wings – technology that has brought to zero the number of miss-drilled holes in the 13 wings already constructed.

The company is also assembling the aircraft using fewer, but larger, structures, and workers are employing advanced adhesives to bond those structures, reducing the use of rivets.

"The wing skin is a single piece. All the ribs are single-piece machined from monolithic structure," says Textron senior vice-president of engineering Brad Thress. "The parts count is probably about 30% lower" than a traditional wing.

The Longitude test programme has involved nearly 50 ground-test articles and five flight-test aircraft.

Textron also pressed two Longitudes into demo service, flying them on tours to cities around the world. Those aircraft have completed long-range legs such as the 3,600nm (6,670km) run between Columbus, Ohio and Paris, and the 3,500nm Singapore-Sidney trip.

While Longitude may be close to certification, development of Textron's largest Cessna-branded business jet – the Hemisphere – remains in limbo.

Textron has marketed that aircraft as a 12-passenger jet with a cruise speed of M0.9 and a 4,500nm range, enough to connect Paris to New York, or Beijing to London.

ENGINE TROUBLE

But the programme remains stalled amid problems with the high-pressure compressor in the jet's Safran Aircraft Engines Silvercrest powerplant.

Safran, which for years has wrestled with Silvercrest issues, is now working on a compressor redesign. Textron expects to learn about the redesign after Safran completes tests scheduled for next July, Thress says.

"That's what we are waiting on," he says. "We are working closely with them and they are giving us engineering performance data as they gain it with respect to modelling the performance of the changes."

Though many details remain uncertain, Silvercrest changes could lead Textron to tweak aspects of Hemisphere, Thress adds.

"We may tailor… the way we extract [bleed air] from the engine, and some things like that on the systems side, to optimise the performance of the airplane and engine integration," he says.

Despite uncertainty, Scholl says Textron remains committed to Silvercrest, insisting Textron's competitive position remains strong despite delays.

"The Hemisphere is still a programme that we are very excited about," he says. "Looking at that space, we feel like we are probably as good if not better than anybody else in bringing new products to the market," Scholl says.

Textron is attacking other market segments with its in-development single-engined Denali and twin-engined SkyCourier – mockups of which will both be on the static display at NBAA.

The company expects that the Denali and SkyCourier will first fly in mid-2019 and achieve certification about a year later.

Textron, which has built four Denali test fuselages, pitches the aircraft as injecting life into a stagnant market segment occupied by the Pilatus PC-12.

Powered by a GE Aviation Catalyst turboprop, Denali will have Garmin G3000 avionics, carry eight to 11 passengers, cruise at 285kt (530km/h) and have a 1,600nm range, Textron says.

Then there is SkyCourier, a twin-turboprop aircraft Textron is marketing as both a cargo and passenger carrier.

SkyCourier, powered by twin Pratt & Whitney Canada PT6A-65SC engines, has a large side cargo door. It will be capable of carrying 2,720kg (6,000lb) of cargo or 19 passengers (or a mix of both), and will have range up to 900nm, Textron says.

FedEx has already ordered up to 100 of the aircraft.

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Source: Flight Daily News