Soldiers and Marines badly hit by enemy fire often have only a short time window during which airlift MEDEVAC can save their life, yet airlifting injured service members in combat presents a set of complex and interwoven challenges. Airplane speeds are necessary to arrive in time for the injured to survive, while helicopter hovering, vertical landing and maneuverability is necessary to access, load and take-off quickly amid dangerous, fast-changing combat circumstances.
Offensive Air Assault Raids over enemy territory are also heavily dependent upon speed and landing or maneuvering agility, as soldiers need to arrive on location, drop from the air, strike and exit critical combat locations before being seen or attacked by an enemy.
Missions of this kind present a need for vertical take-off-and-landing combined with airplane-like speed and range, a blend of operational attributes difficult to merge or combine into a single aircraft.
Bell’s V-280 Valor Tiltrotor
Bell’s V-280 Valor Tiltrotor, now being assessed by the Army in its Future Vertical Lift - Future Long Range Air Assault program, seeks to achieve this blend or synergy between crucial yet typically not interwoven performance attributes. Bell developers drew upon breakthrough levels of propulsion technology, avionics and aircraft design to engineer a new tiltrotor able to hit speeds as fast as 300 knots and more than double the range or combat radius of the existing Black Hawk utility helicopter.
A tiltrotor such as the Bell V-280 Valor is uniquely positioned to perform specific kinds of critical, time-sensitive missions as it can reach its intended location with airplane speeds in moments of combat urgency, yet operate with helicopter-like maneuverability and hovering capacity. A V-280 would, for instance, be able to land in a clustered or congested urban environment without needing a runway or landing strip. This brings an enormous tactical advantage, should soldiers or key personnel need to be evacuated under the threat of an impending enemy attack.
As a compound configuration, the concept of a tiltrotor is to capture and even exceed the performance parameters associated with effective helicopters by introducing the sheer speed, range and flight-path stability of an “airplane.”
The implications of building an aircraft with these abilities are far-reaching, as they can massively decrease risk by removing the need for what the Army calls FARPs, Forward Arming and Refueling points. This kind of operational capability is aligned with Army requirements for the FLRAA program which was conceived of years ago as an aircraft able to introduce breakthrough combat ranges for helicopter aircraft such that attacking forces surging into enemy territory would not need to stop and land to rearm and refuel, thereby exposing itself to enemy attack.
An interesting 2017 essay in the Journal of Marine Engineering & Technology explains how cutting-edge tiltrotor designs are built to “go-beyond” the limitations associated with helicopter flight.
“Helicopters also have major limitations in terms of weight, speed, and range due to their aerodynamics. Tiltrotor technology was developed to overcome the aforementioned limitations. Aircraft can benefit from the lift generated by wings and utilize main rotors as devices for vertical take-off, landing, and after tilting, as well as for providing thrust required for the forward flight in classic airplane mode.”
The airplane-like “lift” provided by the wings is by design engineered to operate in coordination with the “agility” and low-altitude hovering ability enabled by the rotors, adding stability while ensuring maneuverability.
In order to optimize these advantages associated with Tiltrotors, the essay explains, the aircraft needs to be engineered with an effective “control system” for attributes such as Fly-By-Wire technology and flight trajectory stability.
“To perform the proper flight, Fly-By-Wire (FBW) system stabilization is required. To reliably develop such a system, mathematical models of tiltrotor subsystems must be provided,” the paper writes.
While technical specifics unique to a particular proprietary offering in an ongoing competition are not likely to be available for understandable reasons, this kind of need for careful, next-generation engineering to advance new, breakthrough levels of tiltrotor technology may have been part of what Bell developers had in mind when they envisioned and then built the V-280.
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“We went after a clean sheet design based on lessons learned from the V-22 and we want to make an aircraft for the air assault mission. Agility at low speed, efficiency range and reach at very high speeds,” Ryan Ehinger, Bell Vice President and Program Director for FLRAA said in a company video.
This “clean-sheet” design likely pertains to some of the dynamics outlined in the essay pertaining to the technical methods of “optimizing” the advantages of next-generation tiltrotor technology by engineering a robust and capable “control system.”
The essay’s mention of “Fly-by-Wire” technology and its connection to control systems seems quite significant, as it aligns with Bell’s intent to build digital controls and computer processing into its V280-Valor avionics and “control systems” to enable new levels of autonomous navigation and flight.
It makes sense that Bell’s titorotor design would incorporate new levels of digital avionics, sensors and high-speed computing to ensure the mission systems, weapons and sensors could continuously be upgraded as new technology arrives. This will likely draw upon AI-enabled systems able to gather and organize otherwise disconnected streams of incoming sensor data and present optimized solutions and data to human decision-makers. Years ago when the initial requirements for the utility portion of the Army’s Future Vertical Lift Science and Technology demonstration program, the service envisioned technical possibilities which have now matured considerably. The intent was to generate requirements for an air vehicle capable of performing in a superior fashion in the 2030s and beyond, in part using what Army requirement documents referred to as “human-machine” interface wherein computers helped reduce the cognitive burden placed upon pilots by performing a wide range of procedural functions autonomously.
Part of the effort to align with Army requirements includes the maturation of autonomous flight technology, something which Bell has built into the V-280 Valor. As far back as 2019, Bell developers conducted a successful “autonomy demo” wherein the aircraft operated and flew without human intervention.
“We were sitting on the ground on a runway and I flipped a switch. That started the whole autonomous sequence. The aircraft took off from a hover, climbed out and transitioned into cruise mode. Then it returned to the airfield and converted back into helicopter mode and did an approach to a hover...and did it autonomously,” a senior Bell engineer told Warrior in 2019 after the demon. “It opens up the possibility of a self-deployment mission.”
The Army emphasis, even as far back as 2011, was grounded in engineering a new generation of “control systems” in a manner consistent with what the Journal of Marine Engineering & Technology essay on tiltrotors describes. For instance, another key element of the Army’s requirements was described as CFIT, for “Controlled Flight into Terrain.” Much like the Fly by Wire emphasis outlined in the essay on tiltrotors, early Army requirements envisioned the inclusion of new levels of navigational autonomy to improve survivability and operational efficiency for pilots for years into the future.
Bell developers, as described by Ehinger, sought to engineer what he called a “clean-sheet” design based upon this multifaceted Army vision by focusing on new generations of computing, technical standards to enable continued upgradeability through software drops and AI-enabled data analysis organizing information from otherwise separated pools of information to quickly present human decisions makers with an integrated picture.
In development for many years with Bell, the V280 has reached a number of key milestones of relevance to the Army’s plan for the FLRAA helicopter. Called a “score card” by Bell developers, a company document highlights a series of benchmarks achieved by the platforms throughout years of technological maturation. Some of the highlights include low speed agility tests and autonomy demos in 2019, The aircraft took its first flight in 2017, hit 200 knots in 2018 and 300 knots in March of 2019. In 2020, the V-280 Valor went through a number of key Army test flights, survivability assessments and a “sling load” demo before hitting its 215th flight hour in 2021.
Part of the developmental calculus behind the concept of creating a “clean sheet” design was likely immersed in evolving or maturing successful elements of tiltrotor technology. The multi-year development of the V-280 has included extensive flight testing, with both Bell and active-duty Army helicopter pilots. At one point following Army pilot testing, a senior Bell developes explained
“Having Army pilots in our aircraft and flying was very important because I can tell you all day long how responsive and agile it is and how easy it is to fly, but you cannot grasp it until you get in the aircraft. What they brought was current tactics, techniques and procedures. They brought realistic and recent combat experiences, bringing new relevance to our future design,” the senior Bell developer told Warrior.
The Bell Scorecard is focused on continued efforts to build upon, refine and evolve some of the V-280s distinct advantages such as speed and range. These things massively change the paradigm in terms of attack and mission reach, speed to an objective in time-sensitive combat circumstances and survivability of missions by virtue of making the aircraft less vulnerable to enemy fire.
“The element of surprise and survivability coupled with an ability to show low-speed agility within the landing zone. You get the best of a helicopter and the best of a turboprop airplane. You can start in helicopter mode and then convert the rotors out onto the wings. Riding the wings is what can really make a difference and give you speed and range,” a senior Bell developer said.
Kris Osborn is the Defense Editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University