Podcast: Revolutions in Vertical Flight S1 E4 - The Future Battlespace

Welcome to Shephard Studio’s podcast series on Revolutions in Vertical Flight, sponsored by our partner Bell.

Listen on Apple Podcasts, Google Podcasts, Spotify and more.

The Revolutions in Vertical Flight podcast tells the little-known story of the history of rotorcraft, from the autogiro and helicopter, to the tiltrotor and eVTOL platforms in development today. Revolutions in Vertical Flight reveals the stories of a small group of pioneers, the visions and beliefs that drove them, and their approach to invention and innovation.

And the Shephard Studio podcast series looks at the vertical flight innovation underway today, revealing how it will transform military operations and revolutionise urban mobility.

In this episode, we turn to the future and hear how the US Army’s plan to replace its current fleet of helicopters is set to introduce entirely new configurations of rotorcraft. We hear how the US Army believes we are at an “inflection point” and how the new rotorcraft designs are set to change the face of modern warfare.

And we speak to the industry teams vying to bid for two key helicopter programmes and learn how innovation is being brought to bear across their development programmes.

Episode 5 - The Dream of Urban Air Mobility is here

A transcript of this episode is below:

It’s no exaggeration that future rotorcraft technologies will dramatically reshape the way the military conducts operations, with new platforms offering advantages in endurance and manoeuvrability.

Many of these developments have a long heritage, perhaps most notably through the Bell Boeing V-22 Osprey programme, which we covered last episode.

However, recent innovations have driven increased military interest in new rotorcraft configurations beyond the traditional helicopter. This trend is most clearly seen in the US, and sits firmly in the lap of the US Army, which has started the Future Vertical Lift initiative.

This is Mike Hirschberg, the Executive Director of the Vertical Flight Society

Hirschberg: “The technology development over the last 20 or 30 years has really shown there's real potential in advanced configurations and advanced technology. So, in the 1970s and 80s, you know, we, the US military developed some of the most advanced rotorcraft in the world with the Apache and the Black Hawk. And those are just fantastic aircraft that really, no one else in the world has that are as capable and efficient and effective as those aircraft or similar. But then, you know, over the years it was more and more upgrades of existing design. So, you know, with the Huey series, which were originally developed in the, you know, the late 50s and 1960s, you know, they have run out of letters. So, they've, they've got the most advanced versions that you can get with 21st, early 21st century technology.

“But how, if you started from scratch, how would you be able to design an aircraft that's, that's revolutionary? And you can kind of get an analogy between the, the, the old flip phones, you know, and the smartphone. So there is, you know, you can, you can have a fantastic non-smart phone, and it will do kind of the, it'll make phone calls and you can do it, you know, texting, you can do this for a few things, but the difference between a smartphone and a non-smart phone is just tremendous. It's not a phone anymore. It's a, it's a mobile office or a mobile computer that also lets you make phone calls and everything else. So that's the kind of technology leap that the Future Vertical Lift program is, is planning one.  When you start with a clean design and you look at these advanced requirements for range and payload and capabilities speed that the army and other services are interested in, you can really make a huge leap like with you know, Apple and Android with the smartphones that so revolutionary, you can't really even imagine how it's going to be different than a, than a helicopter today. And the Future Vertical Lift programme has really shown that capability.”

Welcome to Shephard Studio Revolutions in Vertical Flight brought to you in partnership with Bell.

Over the course of six episodes, we are looking at the history of vertical flight and discover the key pioneers and revolutionary moments that created the rotorcraft industry we know today.

And we consider the future revolutions, how next generation rotorcraft will shape the future battlespace and hear how innovation underway today will enable the urban air mobility of tomorrow.

Future Vertical Lift is formed of two major programmes:

The Future Attack Reconnaissance Aircraft – or FARA – will provide a light scout, and aims to fill an armed reconnaissance capability gap left by the retirement of the Bell OH-58 Kiowa Warrior.

The second programme – the Future Long-Range Assault Aircraft, or FLRAA – aims to replace Sikorsky’s UH-60 Black Hawk.

FVL should be seen in the context of a rapidly evolving US Army, where new configurations of aircraft will help transform the way in which the service operates.

Here is Carvil Chalk, who is Director of Aviation Development at the US Army’s Combat Capability Development & Missile Center.

Chalk: “It's when you go in aviation from what's shown on the left, the, a single main rotor helicopter and seek out new opportunities. Can you do concepts or combinations of old concepts that are now available because of answers in technology? We do, we're at an inflection point and one hope is that in the decades to come, history will look back off this point in time and see us as a community making a strategic shift in the, our approach to future vertical lift systems. I would perhaps say an enduring legacy that must welcome to the future for future soldiers in aviation.”

The US Army doesn’t just want much faster aircraft with much further range – it wants them to cost the same to build, operate, and maintain as its current helicopters. The new platforms make use of advances in tiltrotor, coaxial and compound technologies, addressing new demands that are being placed on VTOL platforms by what has been dubbed multidomain operations.

This is being driven by the increasing focus on the potential for ‘peer’ conflict, rather than the counter-insurgency missions of recent conflicts. These aircraft must be capable of penetrating cutting-edge Russian and Chinese air defences. The evolutionary improvement on the helicopter designs that the world has known since the 1950s are no longer sufficient.

This is Carl Coffman who is Director of Advanced Vertical Lift Sales and Strategy at Bell.

Coffman: “So we have an enduring fleet now that we've had an evolution of modernisation efforts to continue to increase the capabilities of those aircraft that the enduring fleet aircraft that the war fighters are working with now.  We've had a marked a change in competitor. People refer to our potential adversaries out there, primarily Russians and Chinese as near peer competitors. I would submit to you that there are probably peer competitors. So, we're at that inflection point now where the enduring fleet no longer has the capability to be modernised or upgraded to the point that it's going meet the, the vertical lift requirements on the, on the modern battlefield. So, it's going to take a marked revolution in capability, not an additional evolution in capability. And that's what we're getting to in Bell's efforts with the future attack reconnaissance and long-range assault aircraft.”

Such lofty ambitions underpin the designs vying for FARA. The five competitors are Bell, Boeing, Karem Aircraft, Sikorsky, and a joint venture between AVX Aircraft Company and L3Harris Technologies.

Bell’s entry into the competition is its Bell 360 Invictus, which is based on the 525 Relentless platform. This is Frank Lazzara, who is director of Advanced Vertical Lift Systems Sales and Strategy at Bell speaking on the floor of AUSA tradeshow in October.

Lazzara: “The overall approach is a harmonisation of a series of high technology readiness level technologies and manufacturability readiness level technologies harmonised by a flight control system, automatic digital fly-by-wire flight control system to provide the advanced performance, but again, control risk to schedule and cost.”

The company aims to make the design as sleek as possible in order to keep drag to a minimum.

Lazzara: “You see that in the sleek design of the aircraft. We use the articulated high flapping main rotor, which is not the exact main rotor from the Bell 525 Relentless commercial aircraft, but it is based on that technology and so are the blades. They're advanced blades but for example I’m pointing to blade extenders and those allowed us to take that blade and make it more manufacturable because for example, there's only seven degrees of twist in that blade and we've already gone through some iterations of that and we're seeing great results.”

The wing design plays a naturally important role, taking much of the lift responsibility in high-speed flight.

Lazzara: “There you can see the wing, it's a winged aircraft that has a lift sharing wing in high-speed flight that will assume up to 50% of the lifting responsibility. So, if you want your main rotor to be your primary propulsor or your only propulsor, you need to relieve it of some of its lifting and responsibility. That's what the lift sharing wing does. The combination of that rotor capability, the lift sharing wing, we have a very efficient propulsor.”

Sustainability and self-sufficiency are key elements in Bell's thinking. Here is Mark Thomson, an engineer of advanced vertical lift systems at Bell.

Thomson: “When you looked at the OH-58 Delta as it used to exist in the heavy division in the army that used to go off and just do its job. And it's a lot like what it would need to do in a Russian threat environment, in a screen out in front of the, you know, major US forces or that sort of thing where care and feeding just happens. And, and it, you know, other than making sure, you know, rations and bullets and so forth get to that unit, it takes care of itself, it's self-sufficient. So, it just ties in the same way as our, you know, long-range assault aircraft strategies planned out.”

Affordability is another crucial aspect, particularly in the context of multi-domain operations.

Thomson: “The army has a comprehensive challenge or opportunity when it comes to redefining their capability set. And certainly, in the context of multi-domain operations. So, everything we're doing here at Bell is through the lens of the sustainability piece, but also the affordability piece. If the army goes after all these individual modernization opportunities, looking through a soda straw, which they're not doing, I mean, we're listening to what they're asking for. But if somebody were to go down that route, you would end up with a lot of very expensive sort of exotic solutions that combined are sustainable, both in the normal ups and downs in the fiscal uncertainties that we face, you know, year in and year out or administrations as they change. So we're trying to do, and it started, I came to Bell to initially work with V-280, we're trying to do is make that revolutionary capability affordable and given enough time or money you could probably make anything fly and fly fast, but the army doesn't have all kinds of time in mind.”

The company has worked to develop a culture that supports this outlook. This has been seen throughout its work on the Joint Multi-Role Technology Demonstrator, known as JMR-TD, through which it's developing its V-280 tiltrotor. Here's Frank Lazzara again.

Lazzara: “So that is the, I mean it's a culture here now at Bell and it’s happened very quickly. I've seen it evolve in my three, over three years here. We can create solutions, but we have to create solutions that keep affordability and sustainability firmly in the focal point. And now, starting with JMR-TD and the lessons learned carried forward from the V-22 experience into that programme, applied at that clean sheet design point of that aircraft. And then all those lessons learned carried over to not only FARA, but combined the JMR-TD lessons learned with the Bell 525 Relentless lessons learned and the expertise developed and the talent base developed here at Bell, not only for designing aircraft but fly by wire capability, this rapid approach, all those things combined. Everything with that overarching theme of sustainable affordable because we know that those of us who've lived in the field or you know, been in the military for any length of time, know that if you can't keep it flying, it doesn't matter how good it is, it's got to be in the air.”

This has informed Bell’s approach on technical risk going into both FARA and FLRAA, according to the company.

Ryan Ehinger is Bell’s Program Manager of the V-280 Valor.

Ehinger: “And when you look at the timelines for first year equip that's required, and the risk tolerance or lack of risk tolerance that the army can afford to have on these programmes, you see the V-280 come to bear with 150, you know, 150 flight hours now in test, leveraging a lot of technology off of the V-22, you see a lot of the technologies on FARA as well that I’d deem as low risk, certainly, moving into you know, moving towards a, a program of record in the 2020s. So, that's been Bell's approaches and we don't, we don't have time to make a lot of new discoveries on advanced technologies. We do have time to incorporate a lot of proven technologies that we have today that are capable of meeting the requirements that the army has laid out. So, I think that's a, that's an approach that we're, we're very comfortable with and I think we've demonstrated that on JMR-TD and we'll, we'll certainly demonstrate on that FARA as well.”

As with all major defence programs, the goal is to achieve the best technological result within realistic constraints.

Lazzara: “In all our promises in V-280 and JMR-TD and we took the same approach with Bell 360. What do we, what technologies do we need to combine to get to that capability that we can accomplish on the timeline? Again, if you had unlimited time and money, then it's, you know, you can go after all kinds of interesting things. But when it comes to national security and evolving threat or emerging threat around the world, you don't always have all kinds of time. And in the fiscal environments we've grown accustomed to in our lifetimes, you don't have unlimited funds.”

While FARA will represent a significant advance on past systems, the competitors are working to adapt aspects of their earlier work into their bids.

At Boeing, Shane Openshaw, is the company’s FARA programme manager.

Openshaw: “The futures command customer that has provided the requirements is guiding us the competitors throughout the development phase, focusing on what the Army is seeking in the end. And we have a very strong collaborative relationship with our customer. Bottom line is we are leveraging 60 plus years of domain experience, attack reconnaissance capability experience; not reinventing the past, but leveraging the experience there and advancing it, pulling it forward, pulling it forward, taking advantage of technologies and really focusing acutely and with the requirements and with what the Army's looking for small light and fast agile, lethal survivable with reach flexibility and operational capability. And their requirements set the framework for what is a challenging problem, actually a challenge in general to meet all of the requirements that our focus is on meeting those requirements and creating opportunity to grow and, and continue to make this aircraft to be sustainable and viable for the long term.”

Like its competitors, Boeing is keeping a keen eye on time demands and on the bottom line

Openshaw: “Our focus will be there on the programme of record side; cost is critical schedule to get this capability into the hands of the warfighter soon is the mantra of the Futures Command. The Army is also keenly interested in the cost of the platform, both from a recurring perspective and a unit cost perspective. We are acutely focused on those as well. Next generation sustainment strategies data, reliability, availability, maintainability, strategy and techniques, upfront design for supportability as part of the initial design activity that we're involved in and we are incredibly excited about the opportunity.”

The future of US Army aviation demands that its rotorcraft will be ready and able to defeat enemy air defences well into the future. This is something that has informed Sikorsky's work in the area for the past decade as it has developed its Raider X platform.  Daniel Schultz, president of Sikorsky explains more.

Shultz: “This aircraft is highly manoeuvrable, it has high-speed, it flies like a helicopter in the low-end range and it exceeds all other helicopter capabilities but at the same time it also is a high-speed aircraft. Both wings go forward at the same time so it has lift on both sides. It has the same manoeuvrability as a small aircraft at high speed, at low level and then it turns into a helicopter can land. It is the movement forward at the X only an aircraft that can go forward and lead an assault force forward to path to increase that pathway for the assault aircraft that went forward is an aircraft that could fly and penetrate modern enemy and offenses.”

The aircraft has developed over the years, with the company emphasizing the heritage of the S-97 as a flying platform.

Shultz: “For 11 years, we've been out there flying this aircraft, it's prototype the first X-2 flew at 261 knots. This aircraft right here is over 209 and it's on its way to 250 our next aircraft, the aircraft above that will take it even faster. It's flying today with those down attitudes. He could fly backwards, he could fly forwards, he could fly low speed like any other helicopter. Except twice as good. We're excited about the army having the new solution for the modern battlefield operations on the X and only be made with greater acts.”

The company believes the combination of Sikorsky and Lockheed Martin's heritage gives it an advantage Here is Frank St John, Executive Vice President of Rotary and Mission Systems at Lockheed Martin.

St John: “This is an aircraft like no other and it is a mature flying machine and it does have fantastic capabilities as an aircraft. But to meet the Army's demands in the future and to defeat the threat in 2030 and 2035 and 2040, we're going to need an aircraft that has a very capable set of mission systems and among those mission systems we're going to need capability to be survivable. Lockheed Martin brings unmatched survivability. This requirement, Lockheed Martin brings unmatched aircraft survivability equipment as well as stealth as well as the autonomy capabilities that we have proven that will allow pilots to get into and out of the most dangerous areas.”

Sikorsky had a wide range of factors to consider as it analysed the approach it would take to the fire programme.

This is Tim Malia Sikorsky FARA director speaking on the floor of the AUSA tradeshow in October.

Malia: “I'll just reiterate a couple of things. We, we had a decision to make when we saw this requirement coming where we going to advance one of the helicopters that we had in inventory advanced that designed to make them more capable, kind of an incremental step or did we need to make a much more bold, a bold step and introduce new technology? And that thought process started like 10 years ago as we were flying the extra demonstrator. and as we did our trade studies over the last couple of years, what's the best way to fill this critical gap for the, for the army? The conclusion that we came to was, we know because cost is king; anything that we have to do has to be able to hit the affordability has to be able to hit the affordability targets for the Army. If you can't afford to buy it, you can't afford to deploy it. So first, first filter was anything that we do has to be affordable. The army to fill this critical gap.”

The performance of the aircraft is another critical factor. Not only now, but in the coming decades.

Malia: “After that it was about performance, not performance. Just now in the 2020s which you know, we have a lot of aircrafts out there in the 2020s really started looking forward to what's the, what's the need to be asymmetrically advantaged in the next battle, next war, and what technology would take to do that. We did those trade studies. What we concluded was it was not going to be an incremental step in technology that would allow us to retain a competitive advantage. It's sort of the series in the 2030s, 40s and 50s. We had to make a more radical improvement in the technology to stay ahead of the threats that takes our nation.”

Such demands were key to the development of the X2a compound helicopter featuring a coaxial design. The X2 later developed into the radar program. That's their core ski is pitching for FARA.

Malia: “When you look at it, you see the coaxial technology. We knew that we needed that to provide the growth so that this aircraft can be an enduring capability for the next 30 40, 50 years. If you look at the legacy of the Black Hawk over 40 years in service is still fighting the battle every day. That's what we need out of the FARA. That's what we think the army needs on the FARA. So that drove us to X2 and the Raider excellent just introduced today.”

The Raider X will offer the army much more manoeuvrability, a benefit provided by the coaxial system.

Malia: “In a couple of the points that Dan and Frank tried to make was what does that X2 actually offer the war fighter - much more speed, manoeuvrability is something that you don't really think about that much, the helicopter seems highly overwhelmed, but when you look at this X2, the coaxial rotor system, they'll talk about that in a minute. The manoeuvrability of this aircraft is unequalled by anything else in the aircraft inventory, in service it's extremely manoeuvrable with a rigid rotor system.”

While manoeuvrability is key, survivability is another critical factor that competitors for FARA have to keep in mind.

Malia: “It's great if you can get there fast and manoeuvre when you get there and you have to be survivable in that threat environment. And one of the, one of the things that a Raider does is you don't have a tail rotor system. You don't want to tell it where to drive shaft. You don't have a tail rotor that's strikes critical. You can take damage to the tail of the aircraft. You can take damage to the propulsor that you see on the back of the aircraft. Those are not flight critical holidays. You could lose your propulsor, you could lose your drive shaft, you will still fly home safe.”

AVX and L3Harris are working together to chase the army’s FARA programme. The joint venture is aiming to build flexibility into the design itself. This translates into lower weight, which has a knock-on effect on costs and maintenance demands.

Here is Lance Martin, Senior Manager, Marketing and Communications at L3Harris, giving us a walkaround a mock-up of its proposal.

Martin: “And so that's a key discriminator in that. This aircraft will cost less than the lifecycle costs, less to maintain and that in that flight hour costs, it also makes it lighter, enabled us go faster. So that's, it's just a, a multiplier for us in terms of, of an advantage. You'll also note that Luke mentioned the transmission is a flat pack transmission, which allows us to have this modular Bay that allows us to carry weapons, could carry people. You'll see the other side of the aircraft we have, we have it mocked up for the personnel carry, right? So, you can get six people in the, in the cabin and if, if you wanted to do extended range beyond even the requirement, you could then put in fuel tanks, right and fly them further.”

The aircraft is an innovative compound, coaxial helicopter design with two ducted fans that provide forward and reverse thrust for both high-speed operation and agility.

Martin: “You can hover level engage targets without having to be nosed down to move. That also benefits you when you're coming in for a landing from a degraded visual environment perspective, you don't have the washout as much. Like if you can come in, come to a hover and then go straight down, you don't have to have that angle coming in. That's going to wash up the degradation of your visuals. So, we have the integrated cockpit where again, we reduced the operator workload. You can have two pilots, one pilot or zero pilots, right? Because it’s unmanned is one of the, one of the requirements.”

The companies also see the platform's modular systems architecture as a big discriminator.

Martin: “And that enables this to be connected to this mission system. But not that they couldn't, you couldn't take something out and put something else in. Right.  You're not locked in to just this system, you can grow it. You don't have to go pay special royalties to go add something else.”

The attack element of FARA is a key aspect in this area too. The contenders must emphasize adaptability. Here's Luke Savoy, President of Aviation Services at L3Harris.

Savoy: “So one of the AEs and Farah is obviously all about attack. And this particular case really is demonstrating we have a modular centre bay to the entire platform. We're showing here that one of the configurations of that Bay is an articulated arm that basically extends out a four pack of, of hellfire missiles. But the reality is, and according to, the specifications of the government is really to provision for a volume of space that any number of things can go in from Air Launch to backs to various weapons, rockets to, to hell fires. What we're showing here is actually one of the smaller things that we can actually fit in there. But the platform must be survivable, must defend itself, and it also must be able to reach out and touch an enemy and provide an effect on the battlefield.”

The absence of a tail rotor through the coaxial design brings with it a number of safety benefits.

Savoy: “No, absolutely. I mean, the Army likes to call it the, the night fighter. I have personal experience having been a pilot myself. In the military. I've watched urban environment helicopters pick up a wire around their tail. As they rotate inside of our tight you know, confined alleyway space or a top of a roof, etcetera. Our, our design really limits that footprint. We don't have a, a tail, a tail rotor out there cause of the coaxial design. We use a ducted fan technology that allows us to get to the speeds that we get. Without putting large, gigantic push or prop on the back, we're able to put the fans on the side of the platform, which really reduces the footprint of the platform to where we are within the 40 by 40 parameter. We're not longer, we're, we're within the same footprint of our rotor system, which gives us the ability to turn and pivot without the worry of picking up something on the back of the aircraft.”

The technology within the cockpit has also evolved, notably in terms of the further development of the fly- by -wire systems.

Savoy: “Yeah, I mean I think fly- by- wire is incredibly important with and with an armed scout type of role. There's an, the advancements in sensors, et cetera. There's a lot of workload that gets put on the crew and on top of that, then fly by wire allows us to get the very high performance of the platform, but then allows us to bring some automation types effects, whether it's auto rotate, position hold, etc. That reduces the crew workload, allows them to focus on their sensors, focus on the outside of the aircraft versus on the inside of the aircraft. And those technologies are critical and we're bringing those to bear on this platform.”

While Airbus did not meet the requirements for FARA with its X3 design, the company is still optimistic for its place in the broader arena of future vertical lift technology.

This is Matthieu Louvot is the Executive Vice President of Airbus Helicopters Programmes

Louvot: “Well, I mean we are very confident of our concept. We had the X-3 demonstrated r a few years ago, which showed a very interesting performance at a very affordable cost and we think that all concepts, both preserves a very good flight characteristic of aircraft. Not having speed at the expense of payload, but keeping a lot of payload and mission performance. And also, it's a very affordable solution, but it doesn't drive up massively the cost of the platform. So, we think we have an excellent technical concept. We are having, we are getting support from the European Union programmes, clean sky to develop the demonstrator about it. And well we think it might have a military application one day we were of course disappointed not to be selected for FARA but in the US for the, for the reconnaissance aircraft. But we are open to partnerships. If need be. And we will of course be happy if I know one day us reconsiders our other customers or interesting in a very efficient and affordable speed concept two, we would be happy to provide them, propose them the racer and our XQ based solution. I think it's a, it's a very good concept and well we, we are eager to, to grow it first in civil but also in military applications in the next years. And we feel it's the, it's the speed concept for the 2040.”

With a total of five contenders vying for FARA, it’s all to play for. The army is expected to choose two of the competitors to move ahead and build a prototype.

The US Army is also looking to replace its UH 60 Black Hawk fleet, which is where the FLRAA acquisition comes into play.

The US Marine Corps and the US Special Operations Command are both expected to formally join the programme as it advances. There a number of tough requirements including a hover out of ground effect at take-off of 6,000 feet and a 3,630-kilogram external payload. There is also a requirement to act as an end flight refuelling receiver or supplier.

The two main competitors for the programme are the Sikorsky Boeing SB-1 Defiant and the Bell V-280 Valor tiltrotor. The Defiant is in essence a larger version of the Sikorsky S-97 Raider while the V-280 takes its heritage from the V-22 programme which broke new ground in aviation.

Here's Richard Whittle, author of the definitive history on the V-22 programme.

Whittle: “Well, one of the, one of the things that the opponents of the V-22, I think never quite gave it credit for is that it's, it's not really a helicopter that can fly fast. It's an airplane that can land and take off vertically. And so, you get to the benefits of V-22 from the fact that it, that it is an airplane more than you get the benefit of vertical take-off and landing. And, and of course the V-22 itself can't hover as efficiently as a helicopter can and it's big. But that's why Bell has designed under something called the joint multi-role technology demonstration programme. A new tilt road or a smaller tilt Rover. I think it's designed to carry maybe 11 troops called the V-280 and the 280 stands for the fact that it's meant to fly 280 knots a speed, which is I think in the neighbourhood of twice as fast as, as the best military helicopters go. And they have tried to learn from the, from the, I want to call them design difficulties if not design flow as of the V-22.”

Speed range, payload, survivability and reliability were the key building blocks that underpinned the development of the V -280. Here is Ryan Ehinger again.

Ehinger: “So speaking about the long run, just solve their craft and in particular how the V-280 you know, lines up with that. We started our effort in 2013 under the Joint Multi-Role Technology Demonstrator programme and we looked at the, the five tenets of what they were looking to do with that with that long-range assault aircraft. Of course, at that time it was a future vertical lift capability set three. And so, we focused on speed range, payload, survivability and reliability. And when we started with a clean sheet design, we looked at what is our opportunity from a configuration standpoint to significantly it positively impacts the speed range of this platform for starters. And so for us, for the assault mission, the tilt rotor platform was a natural configuration for us to look at, given the wide, wide success of the V-22 which now has over 500,000 flight hours on that aircraft.”

The company applied a number of lessons learned from the V-22 in development of the V -280 from the wings to the engines.

Ehinger: “In addition to understanding how the tilt rotor or how the tiltrotor flies, how it behaves, how successful it's been with that speed range, with those components. It's understanding from a maintainability standpoint, from a sustainment standpoint reliability, what are all the lessons learned we can take from that platform and roll into a clean sheet design. So, the approach that we took and that's why you see a lot of differences between V-22 and our V-280 concept with the non- rotating engines, the straight wing, things of that nature. It's getting the improved reliability, improved maintainability and significantly improved affordability platform.”

When it comes to addressing sustainability demands, the company looks at the expected threats of the future. Here is Bell’s Mark Thomson.

Thomson: “And a lot of things are kind of like back to the future. If you look at re forgers saying, you know, the 1980s, you had whole units going over to Germany, living out of farmers, Barnes and that sort of thing. And when we look at sustainment, we need that sort of sustainment. We need that kind of sustainment where units can be often in small enough parcels that they're not, they're not noticeable and satellites are not noticeable on the kinds of things that, you know, peers will have to hit us up with. We also want to drive self-sufficiency. So, one to drive one drive, things like tech pubs right on the aircraft. So they're, they're digital tech pubs. They're connected to their health management system. They tell the maintainer what's needed. And then we also want to tie to things like test equipment onboard. So, you know, provide a bus monitor on the, on the aircraft to allow a crew chief to understand what's going on under an engine, MLC as you watch it, and those sorts of things. Want to take care and tool selection. Cause if you are operating out of a barn you want to be able to do the maintenance with his little, you know, tool kit is as is available. So, you know, kind of drives top to bottom right into what our sustainment strategy is.”

The company decided to adopt a clean sheet approach and not just in terms of air vehicle design.

Thomson: “It's not just clothes. She from an air vehicle design perspective, it's also queen sheet and how we incorporate the digital thread and how we design the aircraft. And that allows us to bring in to point, some of these advanced sustainment technologies, techniques and processes that simply didn't exist 30 years ago or 50 years ago when some of these platforms were initially put on, you know, put on a scene or had their first flight opportunities.”

The other major contender for FLRAA is the Sikorsky-Boeing SB-1 Defiant, which performed its first flight in the first quarter of 2019 and has continued testing.

This is Ken Eland, Boeing's director of its future long-range assault aircraft programme.

Eland: “At the end of September last month for a one-hour flight. Continue our power system test bed, PSTB where we're expanding the flight envelope and the capability. We've got that pretty much out to full helicopter speed with no propulsor so normal helicopter speeds as the flight loads we are demonstrating on the PSTB. We'll continue to push that out from an endurance standpoint. We keep the PSTB two times as far as the aircraft, so we run 10 hour blocks on the PSTB and then that authorizes at craft to fly for five hours of those loads. We flew last month, we got up to 20 knots in all directions. One of the key elements there for us is demonstrating the correlation to our predictions. We were flying in ground effect and out of ground effect in very good correlation to our torque predictions. That's important for us to understand that air-dynamically, we're predicting the right amount of power and as you transition from HIGE to HOGE, that's an important inflection point for power to make sure in those data aligns very well to our predictions.”

As of October 2019, the company had conducted four flights on the aircraft comprising three hours total flight time.

Eland: “The acoustics are very good on our aircraft. Actually, we're a little quieter than a regular helicopter. We're operating without the propulsor today. Also, we'll look to bring in here pretty soon. We're looking for propulsor, pretty much 40 knots and above is where we'll produce the propulsor”.

The vibration control system is another key focus of recent demonstrations.

Eland: “Obviously with a rigid rotor, we have a little bit more vibration than a fully articulated rotor. The performance that we take from that, and we need to make sure we take care of the rest of the aircraft with our vibration control system, we've run that both at 50% capability on the first three flights, up to 75% capability on the last flight, and that's behaving very, very well. Keeping all of our vibrations below what an actual Black Hawk vibration level is so far. The other good thing that we've seen so far is actually the vibrations went down a little bit. We didn't predict the vibrations from hover to 20 knots to really do down. They were predicted to stay the same and actually they have gone down a little bit. As we progressed out into years.”

The company is building up to reaching the Defiant’s top speed of 230 knots.

Eland: “Our plan is to continue that on for the remainder of this year, push out into triple digit speeds this year and then later this year and into next year we'll start to bring the propulsor online, push out to our top speed points in the first quarter of next year. As we continue out probably in about 49 increments. We've gone 10 to 20 we're good, 20 to 40 and then 40, 80, 120 and then out, bringing the propulsor in and out past 230 knots.”

Flight testing may influence the company's micro design, but its macro design is likely to remain the same.

Eland: “The macro design as we're looking at an integrated survivable platform to deliver a capability through the testing that we've done, we have a high level of confidence in that. This is now about the micro, does our vibration control system work the way it needs to as there more tailoring that we've done. Is there a tweak that we need to make in the gearbox or something like that It's not the macro design, the guys we resize it for those things? We have agreed a high level of confidence in that basic dentistry from the performance.”

Hirschberg: “So at the beginning, almost 10 years ago with the original studies, the the demonstrator companies have shown that they're able to do just a, a tremendous leap ahead from, from what's from what's capable today.”

This is Mike Hirschberg, who as a reminder, is the Executive Director of the Vertical Flight Society.

Hirschberg: “And have these in the case of Bell and Sikorsky, Boeing have these flying demonstrators with this, you know, great tech, great technology advanced. The V-280 Valor is, you know, takes the basic concept of a tiltrotor, but, but looks at it from a different perspective with not only the 500,000 flight hours that V-22 has but also with some different constraints. So, one of the reasons why the, the V- 22 has a higher download than it would other than it would otherwise is because the rotors had to be small enough to be up for the aircraft to taxi past the Island on the on the ships. So that made it have a higher disc loading and a shorter diameter and shorter wingspan than it would have than it would have liked to have had for the mission for the army. They don't have that requirement. So, you're able to have a more balanced design with, with the performance of the V-280. And also use the lessons learned and the technology advancements in the last 30 years since it was first designed to make, make us, there'll be much more affordable, much really kind of higher performance and more supportable and more, more effective. And kind of the same thing with compound helicopters, compounds have been, have been developing and flown for 50 years. But the question has always been, has the cost with the weight and the weight and cost of an extra engine or propeller or whatever has that been the cost and worth that performance from it.

“And today the answer has been, has been no, but Sikorsky in 2004 with their X2 demonstrator. They've really shown that they can come up with a nice integrated design and have some really impressive performance. And you know, aircraft development always takes longer than expected. It's hard. So, the issues that have prevented Sikorsky Boeing from, from flying more than six flights has, has, doesn't particularly have anything to do with their, their technology. These are just, doesn't have anything to do with the technology. These are just normal aircraft development speed bumps.”

The Pentagon has placed next generation rotorcraft front and centre in its response to the evolving future threat.

Carvil Chalk, the Army's Director for Aviation Development, reiterate his view that we are at an inflection point.

Chalk: “And we reached inflection point here with the establishment of what the Army calls multi-domain operations. And it's an inflection point where we finally come to you, if you will, improve the rotorcraft, get better cramped the way we can. And we have decided to look at rotorcraft differently and pursue new technologies and you pitch it and the more effective way in on an accelerated timeline.”

Whichever companies come out on top as the army works through its future vertical lift vision, what is certain is that the next generation of military rotorcraft are unlikely to look anything like today's helicopters.

Meanwhile, a similar revolution is about to take place in the urban environment promising to transform how we move around our cities.

Next time on Revolutions in Vertical Flight…

A revolution is underway in urban transportation and industry giants and start-ups alike are currently racing to develop electric vertical take-off and landing aircraft.

New eVTOL platforms could turn the visions of science fiction into reality, providing low carbon travel in the urban environment without the need for runaways or the other infrastructure associated with earlier types of aviation.

That's episode five, next time on Revolutions in Vertical Flight available now wherever you get your podcasts

Revolutions in Vertical Flight is brought to you in partnership with Bell - a huge thanks for their support.

Thanks also to the Royal Aeronautical Society, the Vertical Flight Society and the Arthur Young Society. Revolutions in Vertical Flight was written and produced by Tony Skinner with script assistance by Gerrard Cowan and audio edits by Noemi Distefano. And I'm your narrator, Gennifer Becouarn. Until next time.