Bell’s 360 Invictus Readies For Flight But Still Has No Engine

The company’s pitch for the U.S. Army’s Future Attack Recon Aircraft, or FARA, is 95 percent complete and awaiting the GE T901 Improved Turbine Engine so it can begin ground runs ahead of a planned takeoff sometime in 2023. The engine is being developed by another Army office within the Future Vertical Lift effort.

When The War Zone was given a glimpse of Invictus on Jan. 27 it didn’t look 95 percent complete, because it was being reassembled in the company’s hangar in Fort Worth. Many side panels were removed, revealing wiring and other internal components. Very apparent were bright orange wiring and boxes used for instrumentation only during testing and will not be included in the final production aircraft if it gets chosen by the Army.

During a walkaround of Invictus, the gaping hole where the engine will sit was readily apparent atop the fuselage just aft and to the left of the main rotor system. On the other side, the Pratt & Whitney PW207D1, the same engine Bell uses in the Bell 429, was installed as the supplemental power unit, or SPU. That engine provides an “extra oomph” to get the helicopter up – and perhaps beyond – its 180-knot target speed. It also improves autorotation performance should the main engine fail, allowing the aircraft to coast to the ground with some supplemental power, according to Jayme Gonzalez, the 360 Invictus program manager.

Bell did not allow photos of the aircraft to be taken, as it was being reassembled and many of its proprietary internal components were visible. However, Gonzalez screened a video for reporters showing its partial disassembly in Amarillo, where Bell's plant is located. The rotor blades, rotor head assembly, tail rotor, and stub wings were removed before the remainder of the aircraft was wrapped in plastic and loaded on a flatbed trailer. A semi-truck hauled the helicopter’s main body to Fort Worth during what Gonzales said was one of the most nerve-wracking episodes of the development effort thus far.  

Bell did supply photos of the intact prototype from several angles while it was still in one piece in Amarillo. They show little that hasn’t already been revealed. The aircraft resembles a giant, black shark with a swishing tail, pectoral fins and a pointed nose that terminates in a sensor turret and a chin-mounted three-barrel chain gun on a shrouded swiveling mount.

The tandem-cockpit, single-main rotor helicopter sits on a tripod landing gear configuration with two wheels beneath its wings and one extending downward from the tail boom. The canted, open tail rotor configuration, which Bell favored for efficiency’s sake after initially proposing a ducted anti-torque system, is clearly visible.

On the left side of the main rotor assembly is a single inlet for the main engine. There is no inlet on the right side for the SPU. A single exhaust outlet for both engines is on the right side of the aircraft, behind the hump that houses the SPU. Both of those considerations are thought to be efforts to reduce the aircraft’s thermal signature, but Bell has not commented on the inlet-outlet configuration.

In one of the photos, the helicopter’s internal weapons stores – one under each wing – are open, showing twin Common Launch Tubes above a pair of Hellfire missiles.

At least externally, the aircraft looks complete. It even already sports its four flight-ready main rotor blades, according to Keith Flail, Bell’s executive vice president for advanced vertical lift systems. Still, it can’t get off the ground until General Electric delivers its powerplant.

Flail said the engine should be delivered in “the spring” but would not further narrow the timeline.

“We continue to wait for [the] engine from GE, the T901,” Flail said on Jan. 27 during a press tour of the company’s Fort Worth, Texas, headquarters. “Our understanding, because that comes as government-furnished equipment from the Army, is that we should see that in the spring. That's obviously a critical piece for us so that we can get it installed, have all the appropriate airworthiness blessings and certifications, if you will, so that we can start out doing restrained ground runs here.”

The Improved Turbine Engine Program, or ITEP, is a 3,000-shaft-horsepower engine that should be 50 percent more powerful, use 25 percent less fuel, and last 20 percent longer than the GE T0700 engines currently in the UH-60 Black Hawk and AH-64 Apache. Aside from powering FARA, it will be a drop-in replacement engine for those aircraft. But achieving those performance goals has saddled GE with developmental headaches that have persisted even after the Army chose its T901 over the T900 made by a Pratt & Whitney and Honeywell team.

“Our understanding, again, because there's another program office within the Army that manages the engine program, is that … they have a good resolution there in terms of getting us our hardware in that timeframe,” Flail said. “We've continued to watch that in working with GE. For any given program, there's always something that's on the critical path … one of the subcomponents that were driving the schedule.”

Fortunately for Bell, GE has supplied a 3D-printed model of the engine. The gray-and-orange mockup of the powerplant sits next to the aircraft in its new hangar and was provided by GE to perform physical fit checks. Gonzalez said she and her team have performed every system check possible without the engine in place, including applying external power to the cockpit avionics, gearbox, and drive system functional testing. Much of that work is done in the 360 Invictus Systems Integration Lab, an exploded version of the entire inner mechanics and electronics of the aircraft hooked up to monitoring computers and a cockpit simulator.

Of course, flying is the ultimate goal. The Invictus is a competitive prototype going head-to-head with Sikorsky’s Raider X compound coaxial helicopter for FARA. Raider is sitting at Sikorsky’s flight test facility in West Palm Beach, Florida, in about the same state of completion, performing system checks and waiting on the same engine.

In this competition, it could be interpreted that Sikorsky may have a leg up on Bell because the S-97 Raider – a very similar demonstrator aircraft that the Raider X is based directly on – has been flying and gathering test data for years. However, Bell’s Invictus is a conventional helicopter, which the company has plenty of experience building.

As soon as the engine arrives, Both companies are spring-loaded to progress through ground testing and finally lose contact with the earth by year’s end.

“When you start turning rotors and burning gas and showing that the product is real, that's very significant,” Flail added. “So we'll go from restrained to unrestrained ground runs onto first flight, ideally here in 2023.”

The Army has already chosen Bell's V280 Valor advanced tiltrotor as its preferred Future Long Range Assault Aircraft, or FLRAA, to eventually replace at least some of its H-60 Black Hawks. But FARA remains Army aviation officials' top modernization priority, as it still needs to truly fill the role vacated by the retirement of the OH-58D Kiowa Warrior armed scout and more. In this case, there will be an official head-to-head flyoff between Invictus and Raider.

Whoever loses, the Army and the future of attack rotorcraft operations are all but certain to win.

Contact the author: dan@thewarzone.com