Story ID: 
Certification Imminent for Nextant G90XT
By: Matt Thurber
Caption: The company plans to deliver two to four of the remanufactured King Air C90s by year-end.
Word Count: 676
Nextant Aerospace brought its soon-to-be certified G90XT remanufactured King Air C90 to EAA AirVenture 2015 in Oshkosh Wis., not only to highlight the company’s latest product but also to solicit input on the final cabin design and layout. The G90XT features new GE H75-100 engines, the Nextant Regent flight deck based on the Garmin G1000 avionics suite and single-lever power control.

“We’ve finished all the test flying,” said Nextant executive v-p of global sales and marketing Jay Heublein, adding that FAA certification is expected this quarter, with two to four deliveries planned in the fourth quarter.

The Nextant process, first developed with the 400XTi remanufacturing program for the Beechjet 400/400XP, involves completely disassembling the airframe, replacing any worn components, installing fresh engines, avionics and interior and repainting. The G90XT interior gets a new cabin shell and seats designed and manufactured at Nextant’s facilities in Cleveland, Ohio. The GE H75-100 engines replace Pratt & Whitney Canada PT6As (-135As in the later versions), and the H75s are flat-rated to the same maximum power of 550 shp and able to deliver more power at higher altitudes. This enables the G90XT to climb directly to 25,000 feet and burn less fuel while flying about 10 knots faster, according to chief pilot Nathan Marker.

Cabin comfort is improved with a new vapor-cycle air-conditioning system with twice the cooling and three times the airflow of the previous system. One factor that improves the air-conditioning system performance is mounting the evaporators in the cabin, instead of in the nose. A new digital pressurization system is automatically controlled by the Garmin avionics. Cabin noise levels are significantly lower, with a 9.5-dB drop thanks to the same acoustic treatment that Nextant uses on the 400XTi, as well as moving the propeller plane two inches forward of the C90 King Air’s and the tips of the Hartzell props farther from the fuselage.

The Regent flight deck is part of a complete redesign of the G90XT’s cockpit, with the single-lever power control and removal of the existing engine instruments and fuel system panel adding to the uncluttered look. The fuel control panel and engine instruments are all incorporated into the new G1000 avionics.

The cabin shell includes new air ducting to improve comfort. The new seats are fully articulating, and the new production interior was ready to install when the G90XT returned to Cleveland after AirVenture.

The G90XT at AirVenture didn’t have the single-lever power control, which was designed in partnership with GE’s Unison Industries. For pilots, the new power levers make flying much easier because they are tied to single-channel electronic engine controls (with mechanical backup) that automatically prevent overtemping and overtorquing of the H75s. This contributes to longer engine life; the H75 has a 4,000-hour TBO and no hot-section interval. Maintenance is easier, too, because there are no fuel nozzles to clean. Nextant expects the single-lever control by early next year, and G90XTs delivered this year without the new power levers will be retrofitted.

Because so many modifications are done to the G90XT, Nextant engineers developed a new flight manual to reflect the changes. The maintenance manuals include new material for the new engines and systems, and an ATA chapter reference tells the technician exactly where to go in the manuals for pertinent information.

The aircraft shown at Oshkosh is the first G90XT remanufactured by Nextant and the fourth C90 ever built. It has about 13,000 hours on the airframe, according to executive v-p Mark O’Donnell. No structural problems were discovered during the disassembly. “It’s really a stout basic design,” he said.

The G90XT, with the airframe provided by Nextant, will cost $2.8 million, and this includes the Garmin GFC700 autopilot and synthetic vision and Raisbeck aft strakes and wing lockers. Gogo Business Aviation’s Access air-to-ground telecom system and TCAS are available as options.