Military Embedded Systems

Open standards a top concern for U.S. military helicopter avionics


May 16, 2024

Dan Taylor

Technology Editor

Military Embedded Systems

Photo: Army National Guard Sgt. Jovi Prevot

If a U.S. military helicopter pilot could time-travel from the year 1990 to today, that displaced pilot probably wouldn't recognize modern cockpits. Instead of switches and buttons, today's platforms increasingly use sleek displays and customizable dashboards, depending on the mission. Open systems and modular architecture are behind much of this shift.

Modernizing helicopter avionics systems is a different engineering challenge than in a fixed-wing aircraft, especially from a size, weight, and power (SWaP) perspective as space is more limited in rotary craft cockpits. However, similarities also exist when it comes to leveraging open architectures and a modular open systems approach (MOSA) strategy with software and hardware.

Open systems at the forefront

When it comes to designing future avionics for helicopter platforms, the message from the military has been clear: no more black boxes.

“I would say the number one thing we’re looking at from a rotary-wing avionics perspective is open systems,” says Luke Schmidt, senior director of business development at RTX subsidiary Collins Aerospace (Charlotte, North Carolina). “This really started with Congress saying, ‘Hey, all platforms are going to be open.’ And so we’ve taken that seriously.”

Schmidt says a big catalyst for open systems is the U.S. Army’s Future Vertical Lift (FVL) plan to develop five different sizes of aircraft to eventually replace the service’s UH-60 Blackhawk, AH-64 Apache, CH-47 Chinook, and OH-58 Kiowa helicopters.

RTX has been focused on “really understanding the requirements of that and what does open mean, from a requirements perspective,” he explains. “We spent a lot of time on working through that with the Army.”

The basic message from not just the Army but from the U.S. Department of Defense (DoD) is to leverage MOSA in all new platforms and technology upgrades.

“We’re seeing opportunities to open up – partially – on some of the current fleets such as the Blackhawk and the Chinook, and potentially pieces of the Apache,” he says. “The DoD is trying to get away from this black box mentality. There’s always going to be a chassis, but it’s what inside the chassis and the standardization of the chassis. So you can quickly pull a card out and put a new card in, and go iterate quickly on the software. That is really where our focus is.” (Figure 1.)

[Figure 1 | An illustration of the Collins Mosarc avionics concept, described as a modular building block design approach to avionics that meets open systems standards while ensuring the separation of air vehicle and mission system equipment.]

Lockheed Martin, manufacturer of the H-60 and H-53 helicopter platforms via its subsidiary Sikorsky (Stratford, Connecticut), says in a statement that open standards are key to their designs.

“Lockheed Martin continues to align with our customers in the application of MOSA standards to existing and future 21st-century security solutions,” a spokesperson says. “This mission-first approach enables rapid, affordable aircraft avionic insertion as technology or mission requirements dictate.”

The spokesperson adds that achieving the benefits of open systems goes beyond data communication to power, thermal, and environmental requirements, which must be “comprehensively and unequivocally met across all missions.”

A new world for pilots

Flying today’s helicopters certainly look a lot different than they did a quarter century ago. Today’s platforms feature digital displays similar to what might be seen in modern consumer vehicles. RTX showcased a simulator at the Sea-Air-Space exposition in April 2024 that enabled the pilot to toggle between different displays showing different information, such as fuel or armaments or situational awareness information depending on what the pilot needs at any given time.

“Situational awareness is an area we focus on a lot, whether it’s larger displays or helmet technology,” Schmidt says. “How can we bring the right situational awareness to the pilot so they can effectively fly the aircraft and manage the battle and the mission that they’re on? It’s about sensors and how we provide that information to the pilots so they can make the right decision at the right time.”

New technologies on the horizon could change the game even more for pilots five to 10 years from now. Schmidt says RTX is looking at helmet technology and helping pilots operate in a degraded visual environment, which has been an ongoing problem for the services.

“I’m a former Army pilot myself, so if we’re able to crack that code – that degraded visual environment and digital night vision – I think that’s what can be a game-changer,” he says. “It’s important especially knowing the type of environments we ask our helicopter pilots to fly in. It’s not always just about landing in a dusty environment. Sometimes it’s flying through fog.”

Tiltrotors the future?

Tiltrotor platforms can offer military users so much in the way of versatility and agility: The interest in these platforms started at the turn of the century with the V-22 Osprey for the Marines, Navy, and Air Force Special Operations, but the Army has also bet big on this type of platform with its recent selection of Bell’s V-280 Valor for its FVL program. The platform beat out a more conventional helicopter design from Boeing and Sikorsky.

Bell Textron received a $1.3 billion contract in December 2022, which includes $232 million to be spent on continuing preliminary design and development of virtual prototypes of the aircraft, according to an Army statement.

“The new aircraft will extend the reach of U.S. forces’ air assault missions while enabling ground forces to conduct de-centralized operations at farther distances,” according to a Bell statement. “The aircraft will provide greater speed, range and survivability.”

The Army’s requirements call for a platform that can fly at 6,000 feet in high temperatures with up to 12 passengers and travel more than 1,700 nautical miles without refueling. (Figure 2.)

[Figure 2 | An illustration shows the Bell V-280 tiltrotor aircraft – the holder of the U.S. Army contract for the Future Long-Range Assault Aircraft (FLRAA) program – flying a long-range assault mission.]

The need for pilots to alternate between tiltrotor and conventional helicopter platforms makes commonality and open systems all the more important, Schmidt says.

“There could be a lot of commonality there, and I think that’s important, especially if pilots are going from one platform to another,” he says. “It’s really less about that type of helicopter and more about what the flight deck looks like, which can be pretty common despite being different types [of helicopter].”

Sustainability and affordability still a focus

The end user also wants improved sustainability and affordability of platforms. MOSA eases that path by enabling rapid, lower-cost upgrades to the platform versus having to take an aircraft offline for several months to do a major modification or upgrade.

“Open systems is a way the military and the DoD are looking at how they can decrease their sustainment costs on these platforms,” Schmidt says. Another request is that the services want to “fly before they buy,” which plays into the affordability concern and puts pressure on the defense industry to be able to quickly demonstrate capabilities under development without having to rely on a PowerPoint slide, he adds.

“Whether it’s a display, or software, or a card – we want to show them our stuff,” Schmidt says. “I think that goes a long way with the DoD when we’re willing to bring money to the table. We’re not expecting the military to pay for everything.”