FORT WORTH—Bell aims to start test flights of its Bell 360 Invictus demonstrator for the U.S. Army’s Future Attack Reconnaissance Aircraft (FARA) contest in the second half of this year pending delivery of the helicopter’s General Electric T901 turboshaft in March-April.
Bell’s tandem-cockpit, single-main-rotor Invictus is competing for the FARA contest against Sikorsky’s Raider X—a compound-coaxial helicopter with a pusher propeller. Both are designed to be powered by a single T901, although the Bell 360 also incorporates a supplemental power unit based on the Pratt & Whitney Canada PW207D1 turboshaft.
Bell is meanwhile completing functional tests on the 360 demonstrator at its Flight Research Center in Arlington, Texas, where the vehicle was recently reassembled following its transfer from the company’s production facility in Amarillo. Aside from the T901, the vehicle is now 95% complete and will undergo ground tests through the first half of the year, says Jayme Gonzalez, program manager for the Bell 360.
“We should see that (T901) in the spring,” says Keith Flail, Bell’s executive vice president of Future Vertical Lift. “I’m not going to pin it down to a more specific date than that, but that’s obviously a critical piece for us so that Jayme [Gonzalez] can get the engine installed.”
The 3,000 shp-rated GE T901 was chosen by the Army in the Improved Turbine Engine Program (ITEP) powerplant contest for FARA in February 2019, but development was slowed initially by a protest from the losing Honeywell/Pratt & Whitney team. Further delays were caused by the COVID-19 pandemic and knock-on supply chain impacts. Under the revised schedule, engine tests were due to begin in the third quarter of 2021 but finally got underway in March 2022.
Although the Army was hopeful that engines could be delivered to Bell and Sikorsky in November 2022, continuing supply chain issues are thought to have slowed qualification testing for a preliminary flight rating (PFR), which is required before flight tests can start. The T901 is due to complete 1,500 hr. of ground testing before receiving a PFR. Full qualification will be completed after an overall 5,000 hr. of planned engine run time.
“We’ll start out with restrained ground runs here,” Flail says. “We believe that’s critically important. When you start turning rotors and burning gas and showing that the product is real, that’s very significant. So, we’ll go from restrained to unrestrained ground runs onto first flight, ideally here in 2023.
“At the same time in 2023, we’re going to be getting the draft request for proposal for the program of record. So, we’re gearing up for that, looking at what’s going to come from the government for everything that we need to propose for the weapon system,” Flail adds. For this phase, Bell is developing a full-up weapon system version of the Invictus dubbed Increment One.
The Increment One aircraft will look very similar “in terms of scale and size” to the competitive prototype, Flail says. Incorporating lessons learned from the design and build of the demonstrator, increment one development work will include the design and verification of a modular open system architecture (MOSA) with Sierra Nevada, with which Bell recently teamed for FARA.
“We are putting that lab together as a proving ground for MOSA. In 2023, there’s a big event with the Army. Essentially, they bring in a third party. We say we’re MOSA compliant and someone else will come in and see if that’s truly the case. Can you do the things that you need to bring in new capabilities and address obsolescence for vendor lock, and do it affordably? So, we think we’re on the cusp of a great opportunity there,” Flail says.
In contrast to the high intensity of the FARA program, Bell’s work on the V-280 Valor tiltrotor has come to a halt since its December victory in the Army’s Future Long-Range Assault Aircraft (FLRAA) program was challenged by the losing Sikorsky-Boeing team. The Government Accountability Office (GAO) has until April 7 to rule on the protest. Until then, Bell has temporarily reassigned V-280 design and engineering staff to other programs ranging from V-22 and H-1 contracting to the High-Speed VTOL.
“We’re making sure that we’re respecting the process as that all continues,” Flail said. “It’s an official ‘stop work,’ so we can’t work on anything related to the weapons contract. We’re keeping all the folks here and ready to go, because we don’t know exactly when the protest ruling will happen. We’ve got to be spring-loaded and be ready to move back out again,” he adds.
Commenting briefly on the FLRAA, Bell President and CEO Mitch Snyder says “we are patiently waiting and looking forward to getting started on the program.”