Summer 2020 has been, to be blunt, unproductive and deeply frustrating. A combination of rolling furlough, the necessity to use 80% of holiday before the end of September (which realistically for parents of school age children means before the end of August) and short periods of working from home in temperatures over 30 degrees inside the house in thundery humidity have taken their toll.
That’s before even mentioning the uncertainty of redundancies, cuts to budgets and the realisation that it’s likely the commercial aerospace industry won’t recover to its 2019 levels until 2023-2024.
However, there have been some glimmers of hope in the last few weeks of August. On a personal level this was due to finally going on holiday for a week. We stayed in the Highlands of Scotland and experienced astonishingly good weather for most of it!
Within the aerospace industry there have also been some interesting developments. Some weeks ago I wrote about the rescue packages the French and German governments had announced and the lack of a concrete response from the British government. This has been at least partially addressed by FlyZero – an ATI project announced by the Business Secretary during FIA Connect on the 20th July. On the 13th August, a webinar giving an overview of the project took place which can be accessed via YouTube.
The intention of the project is to gather a team of around 100 people drawn from across the industry to study zero emission aircraft concepts. The study will explore the technical and commercial challenges such concepts will encounter and propose means to address them. In particular, emphasis will be on:
- Developing business cases for zero emission aircraft
- Determining policy and investment needs to support the growth and repositioning of the industry
- Creating roadmaps for development and maintenance of critical capabilities for design, development and production of these new aircraft and associated infrastructure.
At the heart of this exercise will be an exercise to develop zero emission aircraft, from conceptual studies through to preliminary design. Alongside the main project, a parallel activity will take place focused on academia to identify where fundamental research is needed and to look at how university courses and facilities will need to evolve to develop the engineers needed for the future.
Judging from the audience questions, the webinar drew participants from a wide range of backgrounds, from large industrial manufacturers, to small and medium enterprises, to freelancers. A number of the questions were concerned with the logistics and management of the project itself. In particular, it is unusual for ATI to be running the project as they typically oversee the funding and administration but hand the leadership to large industrial partners. The explanation given made some sense – projects led by large industrial partners can tend to be biased towards the strategic visions of companies rather than seeing that there might be disruptive innovation from smaller players that could change the market. However, the reality is that delivering a concept – and even taking it to technical demonstration, is not the same as delivering a product. By involving industrial partner secondees as a key part of the project ATI have recognised that the learning and the ecosystem developed through the project needs to be integrated back into industry to be of real benefit.
Other questions raised the topic of what type of zero emission concept will be the main area of focus. During the webinar both the expressions “net zero” and “zero emissions” were used. There were also mentions in the Q & A of Sustainable Aviation Fuel (SAF), hybrid-electric / electric propulsion and hydrogen propulsion. However, there was not a conclusive answer. The question is an important one for a variety of reasons. First of all, the technical challenges of each type of aircraft are different.
Today, aircraft can already use a blend of 50/50 conventional Jet A1 and SAF without any conversion or modification needed. Use of larger proportions of SAF implies infrastructure challenges to scale up production of the fuel – but requires no change in distribution systems or storage. For the aircraft themselves, higher prices of fuel would drive the need to continue enhancing performance and reducing weight – yet not necessitate changes in operation or certification to the same degree as the other solutions. Technological solutions would be evolution of today’s aircraft – higher aspect ratio wings, laminar flow, advanced load control, ultra high bypass engines The biggest drawback of this solution is that at best it could be carbon neutral if synthetic fuel is made via carbon capture, as it would still release CO2 and NOx.
Hybrid electric and electric aircraft have seen some impressive early demonstration. The Airbus Group Innovations E-Fan flew at airshows as early as 2014 and more recently there have been demonstrations of small aircraft in the USA and at Cranfield. The ambitious E-Fan X demonstrator project from Airbus, Rolls-Royce and Siemens was brought to a close earlier this year before converting the Avro RJ100 for flight test demonstration. However, ground based demonstrations of the electrical systems and wind tunnel testing have brought considerable knowledge and better understanding of the longer term challenges. The main blocking point at present is the gap between the power demand of a short range commercial aircraft and the power density from existing battery technologies. However, as a solution for smaller aircraft it is already appealing and the solution for larger aircraft may be in use of batteries or fuel cells as a means of providing power for supplementary systems e.g. entertainment. The Flight Physics challenges of these aircraft are often seen as secondary to the systems challenges – yet the massive cooling requirements for batteries lead to the need for large heat exchangers that require significant air intake and exhaust. Integration of these intakes and exhausts was one of the challenges for retrofitting an Avro RJ100. For a new product – it would be necessary to find a way to integrate these elements to the configuration in a way that was neutral.
For electric aircraft – there are also implications for operational flight and loads cases. An aircraft that doesn’t consume fuel, or consumes proportionally less fuel, will not change mass or require trim changes for centre of gravity. This leads to landing loads equal to take-off loads. It also means the conventional flight path of aircraft increasing in altitude as they reduce in weight is no longer necessary – which could change how designs for longer routes are optimised aerodynamically.
In the last few months there has been a particular surge in enthusiasm for hydrogen as the future solution for commercial aircraft. Cranfield is actively engaged in a lot of research for hydrogen as a solution for aviation. Start-ups like ZeroAvia are targetting a powertrain solution for small regional aircraft. Earlier this week, former Airbus and UTC Chief Technology Officer Paul Eremenko announced his latest venture, Universal Hydrogen which focuses on a simple, universal pod system for supplying hydrogen to aircraft initially for use in fuel cells on regional aircraft but with the potential to supply hydrogen burning larger aircraft.
The flight physics challenges for a hydrogen powered aircraft are predominantly linked to storage constraints for large volumes and regulatory implications. This could lead to consideration of novel configurations such as blended wing bodies to manage the volume in an aerodynamically efficient way. The challenge becomes significantly greater the more distance is needed between the passengers and the fuel volume. Potentially there could also be some niche cryogenic implications for icing protection, transition behaviour on laminar flow aircraft.
Beyond the technical challenges – there are also geopolitical and economic questions to consider. Making the UK a centre of excellence for hybrid electric small aircraft development will make little sense if the commercial aerospace industry universally adopts hydrogen for anything larger than twenty seats. Today there doesn’t seem to be a definitive answer to the question of the long term solution. In the meantime, it seems sensible to develop technology that can serve a variety of aircraft designs – and capabilities and tools that can incorporate the characterisation of those technologies equally well.
Finally, there was a question asked about co-operating with neighbouring countries that have announced research into zero emissions aircraft, namely France and Germany. Currently, FlyZero is focused solely on UK aerospace industry development. This is not unusual or exceptional in these times – yet it would be a mistake if it is seen as a moment to restore the landscape of the past where multiple UK based companies manufactured entire aircraft. Whilst this past is often fondly remembered – the reality is that many of the products were never commercial successes and even the more prolific aircraft were limited in number to hundreds. Variants of the same narrative are seen in the experiences of France, Germany, Spain, Sweden and the Netherlands. Even whilst Boeing retains large production facilities in Seattle, it subcontracts large components to be manufactured in the Far East. The aspiration of FlyZero should be:
- To consolidate and grow the areas where the UK already is a centre of excellence for new zero emissions products
- To identify where new opportunities from new technology or energy supply and infrastructure can be developed into future centres of excellence
Acting as a strong player in an international industry with confidence in its expertise and capability is the goal. Making limited production runs of aircraft so that we can stick “Made in Britain” labels on them is not. Thus far the ATI seems to be going in the right direction.