Synopsis: This keynote presentation will discuss new developments in hybrid electric propulsion systems for aircraft.

Synopsis: In this presentation, Lowell Foster, who heads up global innovation and engineering for the General Aviation Manufacturers Association will update the initiatives taking place in the development of hybrid and electric aviation and the progress towards certification and operations of these aircraft.

Synopsis: Although the ongoing Covid-19 pandemic has had an unprecedented impact on human life, the global economy and the aviation ecosystem, there are many research projects that are delivering outstanding results and innovations. The forthcoming EU research and innovation program for the 2021-2027 period, Horizon Europe, will pay particular attention to disruptive and innovative aviation technologies in support of wider EU policy objectives, namely climate neutrality and digital transformation. Climate neutrality for aviation is a complex, long-term, international challenge. Apart from the required technological innovations, safety should remain a top-level priority. Furthermore, potential financial investments for carbon-free or low-carbon fuels as well as airport infrastructures are considerable. Recognizing that the ambitious European climate neutrality goals cannot be achieved by one company or one nation alone, Europe takes the lead together with all the relevant stakeholders. In this presentation, we will review the European aviation research policy and the main research projects that contribute to the electric and hybrid aerospace.

Synopsis: A concept of an unmanned amphibian aircraft with maximum take-off mass of 8,000kg and distributed along-wing propellers rotated by the electric motors is presented. The electric motors are powered by a turbogenerator based on a helicopter turboshaft engine with a maximum output power of 1,600kW. Such a distributed propulsion system provides low-stall take-off and landing speed that allows the aircraft to draw water from relatively small lakes and rivers. Also, it allows water bombing at low speeds, which considerably increases the efficiency of firefighting operations.

Synopsis: In this presentation, Dr Josef Kallo, who oversees electrochemical systems integration, including fuel cells, batteries and propulsion for aircraft at DLR, will outline the experience gained from the HY4 flight test campaign and progress toward a hydrogen fuel cell propulsion system for passenger aircraft.

Synopsis: For the last couple of years the Netherlands Aerospace Centre has worked on hydrogen-powered electrical systems for aviation with the aim of reducing CO2 emissions. A technology roadmap is defined for a gradual increase in electrical power up to 1MW and beyond. An example is the hydrogen-powered drone HYDRA-1 and the new fixed-wing platform HYDRA-2, the progress of which will be highlighted. NLR acquired an electrical aircraft – the Pipistrel Velis Electro – and is conducting flight tests on a regular basis. The Pipistrel is being prepared for a hydrogen range extender for which certification is underway.

Synopsis: The use of hybrid electric propulsion for commercial transport aircraft could be strongly limited by available battery power density. Nevertheless, specific characteristics of electric motors could be used to design non-conventional configurations using innovative solutions such as distributed electrical propulsion (DEP), wing-tip propeller and boundary-layer ingestion. All these aspects have to be taken into account in the preliminary design phase. Preliminary design tools are based on a classical approach and are unable to evaluate these effects. Extensive CFD has been performed and used to derive simplified methods to simulate DEP, tip propeller and BLI in the preliminary design.

Synopsis: Ampaire is test flying the world’s largest hybrid electric plane, with plans to conduct demonstration flights on commuter airline routes in the coming months. The company is on a fast track to introducing cleaner, quieter, less costly aircraft to benefit airline and general aviation operators, and improve the passenger experience. The future begins with in-service aircraft adapted for electric propulsion and proceeds to exciting new, clean-sheet, high-performance all-electric aircraft. Ampaire co-founder and CEO Kevin Noertker returns to update the symposium on Ampaire’s vision, plans and industry-leading progress toward making a new era of electric aircraft a reality.

Synopsis: The presentation will discuss ZeroAvia’s breakthrough zero-emission, hydrogen-fueled electric powertrain for commercial airlines. The goal is to accelerate the transition to sustainable aviation by giving aviation customers and airframe manufacturers a zero-emission option for regional flights, which are roughly half the world’s airline trips. Through an in-depth analysis, the presentation will explore the power of hydrogen fuel cells and their capabilities in aerospace, reaching hundreds of miles due to their power dynamics compared with batteries.

Synopsis: This presentation will provide an overview of the current activities at Vertical Aerospace Ltd and the technology challenges the company faces in the development of a new winged eVTOL that it aims to certify by 2024.

Synopsis: The presentation will address the challenges in creating a digital twin by modeling and simulating a high-power-density generator system that enables hybrid electric propulsion. Compact and efficient generators are key technologies that support the goals of hybrid electric propulsion, and being able to analyze their performance and behavior as a system in the early design stages is critical to developing an optimum system. Modeling challenges, technical solutions and simulation results will be presented.

Synopsis: Lithium-ion and its future variants is the only battery technology that can meet the electrification and hybridization target of regional and urban air vehicles between 2020 and 2030, outlined by ATI and other government authorities. In recent years, battery energy and power density have seen a gradual increase; however, battery thermal runaway and safety prognosis have received little research focus. This likely due to the fact that lithium-ion battery research is currently dominated by non-aerospace applications such as automotive, which don’t share the same strict safety regulations. WMG is one of the leading academic organizations developing battery functional safety prognosis systems for aerospace applications.

Synopsis: Electrification of flight brings the potential for new types of aircraft, increased sustainability, and operating cost reductions. As the industry applies electric propulsion, there are common challenges related to endurance, mission capability, and operational safety compliance when relying on batteries as the primary onboard energy source. Hybrid power is the key to enabling highly capable aircraft that deliver on the benefits of electrification without compromising utility and safety.

Synopsis: CharIN is the association representing the international charging standard CCS and using the ISO 15118 communication protocol originally designed for electric vehicles. This standard has been accepted in many other industries from forklifts to eVTOLs and ferries. The latest MCS (Megawatt Charging System) charging system allows for charging of 4.5MW of e-planes and more. The MCS also uses the ISO 15118 standard and allows for international roaming during charging sessions in different e-ports, and fast and automated charging while making secure payments without human interaction. Where needed, it can also provide demand/response tools to shave off peak loads by grid or DS operators. From our experience in the EV ecosystem, we came to the conclusion that only if a single high-power charging standard is adopted within an industry, will worldwide investment in regional and global charging infrastructure happen in earnest. This also seems to be key for the eVTOL, e-plane industry to take off.

Synopsis: VoltAero has developed the world’s first parallel and series distributed hybrid propulsion system, which will power a family of general aviation aircraft – Cassio – with seating capacities of four to 10 passengers. Its proprietary propulsion system delivers a total output of 600kW, enabling flight distances of up to 1,200km in a heavy-hybrid mode, offering 3.5 hours of flight autonomy. Benefitting from this propulsion configuration and Cassio’s modular design, the aircraft can be configured for different flight modes that vary from pure-electric flight (with a range of up to 200km) to heavy-hybrid mode, using the full 600kW energy output for distances of more than 600km. As most of the short-haul routes in Europe have flight distances of 100-1,000km, Cassio will provide a new mode of transportation that will enable access to more communities in less time, enhance regional mobility and alleviate road congestion problems – achieving all these goals safely and in an environmentally and customer-friendly manner. VoltAero’s hybrid propulsion system qualifies as a breakthrough innovation because of its scalability to larger aircraft, as well as to other applications such as helicopters and unmanned aerial vehicles (UAVs).

Synopsis: Hybrid electric or full-electric aircraft propulsion systems powered by energy storage systems can considerably reduce aircraft CO2, NOx emissions and noise. This market potential offers novel opportunities to the aviation industry. Propulsion batteries for aviation present many challenges, from cell selection and total energy storage required, to the form factor and standard constraints and certification. Challenges lie in increasing the energy and power density of lithium battery systems and optimizing aircraft integration while providing safe and reliable solutions. Emerging new chemistries and solid-state technology are game-changers for the industry.

Synopsis: The combination of unconventional aircraft configurations with hybrid-electric propulsion has the potential to cut CO2 emissions and pave the way for sustainable aviation. This paper aims to present a methodology for the conceptual design of hybrid electric aircraft with box-wing configuration, known as PrandtlPlane. The methodology is based on the interaction between two in-house-developed tools, the first aiming to size the hybrid electric system for a given mission and the second aiming to maximize the aircraft performance. The activity is part of the Italian PROSIB research project, the goal of which is to develop enabling technologies for the regional aircraft category.

Synopsis: The presentation covers the basics of power density for electric machines and the key driving factors. It also explores how the choice of direct-drive or geared affects the overall system in terms of mass, efficiency and complexity, with specific examples.

Synopsis: Altran’s research regarding future airports and hybrid and electric aircraft in R&D projects offers a good knowledge base for developing new electromagnetic technologies, taking into account the advantages of electrical systems development. This project has designed a new solution to reduce the aircraft’s speed during the landing phase in adverse weather conditions due to rain, snow or ice.

Synopsis: Entry-into-service projections for various platforms for different aircraft classes will be presented in light of the latest business environment. System requirements will be identified to satisfy various platforms. Architectural, systems and components provisions to achieve these platform goals will be presented. Consideration will be given to the level of integration, power distribution buses, partial discharge effects, EMI, power quality, high-temperature hardware and thermal management. Quantitative data will be shown to support the proposed solutions. Electric engines, power generation and distribution systems will be covered. Improvements in electric rotating machines and power electronics components will be discussed.

Synopsis: To achieve the European Green Deal objectives, there must be a thorough focus on infrastructure readiness, rather than only a new generation of flying vehicles. With hybrid electric aircraft entering the market for short- to medium-range missions, the ground infrastructure at airports must also keep pace with the technology evolution. The studies performed within the European MAHEPA project identified the key enabling aspects to consider for the creation of a comprehensive recharging and refueling infrastructure network to fully enable the widespread uptake of low- and zero-emission air transport. In this presentation, guidelines for infrastructure readiness will be discussed and potential paths for airport equipage revealed.

Synopsis: This presentation will provide a case study of the hydrogen-electropropulsion system being developed as part of the Element One aircraft program, a regional hydrogen-electric platform designed to carry passengers over long distances without emitting any carbon during flight. This program merges HES Energy Systems’ ultralight hydrogen fuel cell expertise with the latest distributed electric propulsion technologies. The modularity of the system simplifies the scale-up from drones to small planes while ensuring safety with redundancies and fast refueling.

Synopsis: LH2PlasmaRay 6.66 is an electric vertical take‐off and landing (eVTOL) air taxi and regional air mobility system with two separate propulsion units for VTOL and cruise. It is powered by LiPo batteries with +20kWh and 10 Intelligent Energy 4.8kW fuel cell units. The specific energy is 378Wh/kg with gaseous and 1,099Wh/kg with liquid hydrogen (LH2). LH2PlasmaRay 6.66 could store about 12kg of liquid hydrogen, which would provide 199kWh of electrical energy. So an LH2PlasmaRay 6.66 would have a range of 1,000km for business routes like Berlin‐London or Berlin-Paris.

Synopsis: Operating a mixed fleet of eVTOLs demands that manufacturers standardize the charging process. The participation of key market players in committees like the EuroCAE WG-112 shows that they aim to capitalize on proven automotive technology. From a pure-electric point of view, DC charging is the preferred solution to ensure minimum charging time due to high-power charging. DC charging requires continued digital communication between eVTOL and charging station so that the stations at any point in time know the voltage and current requirements of the battery. This means both sides have to agree on a common protocol to exchange this data in a way that enables any aircraft to charge at any charging station. Therefore, EUROCAE has taken action to standardize this protocol to ensure proper interoperation of the associated parties. This lecture presents the current status of standardization and outlines the possibilities it might offer to the industry.

Synopsis: With the development of hybrid and electric VTOL air taxis, we are called to support an emerging technology that has an amazing impact on the way people are transported, enabling safer and greener urban mobility. Many challenges need to be solved, such as the use of composite materials, hybrid and fully electric propulsion, passenger safety and air traffic management. Furthermore, VTOL aircraft must be certified for HIRF and lightning. This presentation reviews the standards to be applied, and discusses the challenges of VTOL vehicles with regard to the lightning and HIRF environments. Finally, we will illustrate the role of numerical modeling for certification.

Synopsis: Batteries are the costliest and most critical component of an electrical powertrain on an aircraft. They must be properly tested for functionality, performance, durability and SOC/SOH. These tests may become complex and can take an impractical amount of time and resources. For new programs, the engineering team may be concerned about how much testing is sufficient and how they can efficiently complete battery V&V testing. This session will outline industry expectations of battery V&V. It will describe what tests should be done on battery cells, modules, packs and electronics, and will define a cost-effective and time-efficient test workflow. Test standards, cycling profiles, test cases and performance expectations will be evaluated over all stages of battery development, from performance evaluation and functional validation, to environmental and durability testing, to end-of-line production test, to warranty and end-of-life testing.

Synopsis: Considering the current kerosene-centric aviation system, a direct translation to a zero-emission solution seems impossible with today’s technology. The only option with ‘true zero’ emissions in flight is fully electric, but this technology has size and range limitations, requiring a complete rethink of our aviation paradigm. We consider a concept in which smaller aircraft fly frequent legs to and from smaller airports in a true point-to-point model. These services can be fully sustainable, while also being more convenient and faster for passengers. NLR and Roland Berger have studied the technical potential and economic viability of such a concept.

Synopsis: Over the last decade, new technologies in power electronics, such as WBG devices, have enabled the development of systems with the highest volumetric and gravimetric power densities. The presentation will give a short overview of the latest trends in power electronics design and how to benefit from internal power electronics topologies on a system level. Intelligent utilization of existing parasitics in power devices enables an advanced switching strategy called ‘zero overvoltage switching’ with major improvements in switching efficiency. Current project examples will be given for a 10kW isolated SiC HV/LV DC-DC converter for fuel cell auxiliaries applications and an air-cooled 15kW SiC drive inverter with a fail-operational six-phase topology.

Synopsis: The arrival of hydrogen aviation has been hindered by the energy density limitations of lithium-ion batteries and the specific power limitations of existing hydrogen fuel cell systems. In this presentation, Dr. Alex Ivanenko will demonstrate how an internationally-renowned team of scientists and engineers created a NASA award-winning hydrogen fuel cell system for aviation and aeronautics. HyPoint's revolutionary approach utilizes compressed air for both cooling and oxygen supply to deliver a high-temperature (HTPEM) fuel cell system that is three times lighter than comparable liquid-cooled low-temperature (LTPEM) fuel cell systems and achieves up to 2,000 watts per kilogram of specific power and up to 1,500 watt-hours per kilogram of energy density. The team also developed a number of technical innovations including lightweight bipolar plates and a highly conductive, corrosion-resistant coating in order to radically outperform existing systems.

Synopsis: LIFT Aircraft's vision is to bring the thrill and joy of personal flight to everyone, in a way that improves flight safety statistics by one order of magnitude compared with legacy general aviation aircraft and procedures. Given that we aim to achieve this by paradigm-changing aircraft technologies flown by potentially inexperienced people holding no pilot's license, the question of 'how' is the first that pops up. We believe it is entirely possible, but it will take a holistic approach that addresses technical, procedural and social aspects. In our speech, we will introduce the most crucial milestones toward proving the concept; the ones achieved as well as the ones still ahead.

Synopsis: Ultracapacitors are specially designed and constructed to deliver high capacitance and power density. However, commercially available supercapacitors are not designed to withstand the hostile conditions to which electronic systems for aerospace and defense systems are subjected. When applications are constrained by size, weight and power, power system selection is critical. Nanoramic’s low-temperature ultracapacitors provide a way to marry highly energy-dense modules like batteries with highly power-dense ultracapacitors in a way that doesn’t compromise the total mass of the system.

Synopsis: This presentation will review the project to develop and integrate the propulsion system for the APUS i-5 plane, which seeks to demonstrate the practical application of hybrid electric technology for a 4,500kg conventional take-off and landing flight test vehicle. The system could be used across a range of transport platforms to enable distributed electric propulsion, and will undergo several iterations to continuously improve power and energy density on a complete system level to enable the introduction of low-emission hybrid electric platforms into the market.

Synopsis: Considering the current kerosene-centric aviation system, a direct translation to a zero-emission solution seems impossible with today’s technology. The only option with ‘true zero’ emissions in flight is fully electric, but this technology has size and range limitations, requiring a complete rethink of our aviation paradigm. We consider a concept in which smaller aircraft fly frequent legs to and from smaller airports in a true point-to-point model. These services can be fully sustainable, while also being more convenient and faster for passengers. NLR and Roland Berger have studied the technical potential and economic viability of such a concept.

Synopsis: Electric aircraft are coming. The development of electric and hybrid electric aircraft is accelerating rapidly. There are many potential benefits of electric aircraft, including lower costs and reduced environmental impacts. A realistic timeline for transport electric aircraft could see small commuter planes flying passengers before 2025, and then see a progressive adoption of these technologies by flight operators. The advent of electric aircraft offers significant opportunities and disruptions for airports and aviation systems. Airports and their stakeholders may have new roles to play regarding the generation, storage and distribution of electricity and hydrogen as aviation energy vectors. At the same time, electric aircraft may affect revenue from fuel sales. Accommodating electric aircraft requires adequate policies and careful planning, as well as design features, standards and operational procedures that ensure safe and efficient operations.

Synopsis: Vertiports represent the new eVTOL interface between land and air travel for passengers and freight. This kind of infrastructure, though inspired by current heliports, faces the same degree of challenges as new aircraft in terms of integration within the current environment and certification for use. Among the issues to tackle are fire and rescue strategies, electric power supply, passenger experience and air traffic control strategies. This presentation will provide an overview of these matters.

Synopsis: Many people are talking about the possibility of using hydrogen as aircraft fuel because, however used, it has the advantage of not creating any CO2 as an emission by-product. But the change to H2 is far more profound in a number of ways. This adds complexity but can also create significant advantages for the designer and allow new techniques to be adopted. In particular, due to its volumetric density, hydrogen has to be used in its liquid cryogenic form (LH2) to allow an acceptable volumetric density. Even so, this still has a volumetric density of around 35% of jet fuel and therefore aircraft modifications are required to accommodate the fuel volume. Nevertheless, the use of LH2 is perfectly adapted to allow the use of fuel cells and a superconducting electric power system. This can create a scalable, highly efficient electric propulsion system to power these new low/zero-emission aircraft. The key to achieving this is to look at the overall design efficiency, which seems capable of producing scalable, low or emission-free aircraft, right across the range of applications. The presentation will discuss these approaches.

Synopsis: The Flexcraft project converges the expertise of a consortium of companies and institutions (Almadesign, IST, SET, Embraer, Inegi) in the fields of industrial design, aeronautical engineering, process engineering and aircraft manufacturing, to develop an urban air transportation solution. This presentation outlines the opportunities of hybrid electric propulsion and the impact on designing the passenger experience via innovative cabin layouts and modular fuselage configurations. The Flexible Aircraft was tested using a remotely operated scaled demonstrator, a full-size cabin mock-up and an innovative manufacturing process, bringing new opportunities for flying multi-modal vehicles that promise advantages in low-level urban airspaces.

Synopsis: As aerospace engineers design new aircraft powered by distributed electric propulsion systems, they face new challenges to ensure that their designs are safe and efficient. Changes to the size, number and location of the propulsion units on the aircraft lead to new design architectures that require additional testing. In this presentation, we will discuss how factors such as modal, flutter, structural fatigue, motor/inverter characterization can be evaluated using a holistic measurement approach to validate a new aircraft design.

Synopsis: eVTOL propulsion systems fall into two camps: multiple rotor systems with simplex power channels per rotor and low number of rotors each powered with a fault-tolerant electrical drive system. The paper will compare these two approaches and present architectures for fault-tolerant electrical drives. The route to achieving 10-7 per flight hour availability on a single output shaft electrical drive will be described. The presentation will be illustrated with practical results from radial- and axial-flux fault-tolerant electrical drives and will describe the design processes and tools that can be used.

Synopsis: This presentation will look into the promise made by electrification and will offer a threshold upon which the electric aircraft becomes a technical and economic feasibility, competitive with its piston-engine counterparts. It will review topics like operational weight (battery weight), entry into service (battery availability), acquisition costs (battery costs), operational costs (electricity costs) and turnaround time (charging time). Finally, the presentation will address the availability of funding for the 200+ projects currently under development, the extra costs required for certification in comparison with the less expensive remotorization of legacy models, and the impact of the 5G high-speed electronic office versus traveling.

Synopsis: An advanced motor design is proposed to address the challenging needs of electric drive systems applicable to electric and hybrid propulsion. A novel system architecture will be considered, and its advantages quantified in line with the major components like electric rotating machines, controllers and speed-reduction elements. Criteria for selection of the novel architecture will be presented, focusing on new materials, rotor and stator manufacturing techniques, power electronics, thermal management, power distribution and optimization. Different levels of system and component integration will be considered as major drivers to achieve the best power density. Results from trade-off studies will be presented.

Synopsis: The percentage of software in avionics is reaching new heights due to the electrification of engines. The first come first served principle is putting immense pressure on manufacturers to deliver fast and with the highest quality. Compliance with the software testing recommendations in DO-178C, as described in Section 6.4, provides an additional challenge for software development departments. All these issues can be addressed with a test automation, simulation, and parallelization solution tailored to the Avionic. In this workshop, you will learn five practical ways to improve test environments and structural coverage requirements. It will explain how a continuous quality workflow solves the problems of daily testing with a growing code base. A live demonstration will illustrate the different stages of test automation. Capturing structural coverage of unit, integration, and system-level tests and aggregating them into a unified report, the parallelization of test case execution the change-based test case execution and continuous testing.

Synopsis: The presentation will deal with aircraft preliminary design tools developed at the University of Naples to deal with hybrid and electric aircraft. The methodologies and tools developed integrate aero-propulsive interaction (DEP and tip propellers) as well as electric powertrain technologies (batteries and fuel cells). The preliminary design phase uses a modified semi-empirical approach, and more detailed analysis is made with a simulation-based approach that also includes estimations of structural effects arising from electric propulsive chain integration. National financed projects (PROSIB) and CS2 projects are currently running on the design of regional hybrid aircraft.

Synopsis: The future of eVTOLs and hVTOLs will depend on designing aircraft that provide superior performance, meet the highest safety standards, operate with very low noise, and gain acceptance by the regulatory authorities, pilots and passengers. Fundamental to those objectives are aerodynamic and operational efficiencies, as well as appropriate system design architectures. The aerodynamics of various vertical takeoff and landing machines have been well documented over the past decades. The battery and cell technology and roadmap are well understood, as are the requirements of SAE International’s ARP4754 and ARP4761. The key to the success of first-generation eVTOL and hVTOL aircraft is designing within the bounds of these constraints. The Jaunt Journey VTOL design with current battery-electric and hybrid technology offers the most aerodynamically efficient platform, capable of achieving the highest levels of certification standards within existing regulations.

Synopsis: Power systems and their associated components are increasingly being relied on for more and more systems within aircraft, and are the primary source of power and propulsion in the latest electric/hybrid architectures. This presentation will discuss what should be considered when designing power systems such as power supplies and converters for electric/hybrid aircraft.

Synopsis: High power density in e-motors is essential for future developments of electrical propulsion. Values of 20kW/kg can be achieved using very-high-permeability electrical steel, high currents, high frequency and special cooling systems with critical CO2. All the above have to be used while ensuring that the fault operating rate stays at 1e-9 value. Rare earth magnets can be used, but are not absolutely necessary. Several solutions and configurations are investigated and presented: inner and outer rotor rare earth magnet motors, induction motors and switched reluctance motors. Proposals for new research directions for e-motors are considered in this presentation.

Synopsis: Imagine for a second if every car maker’s fuel pump was different. How inconvenient and inefficient the refueling experience would be. This is essentially what has been happening for electric cars, as different manufacturers implemented different charging standards in different countries. The chargers provided by different manufacturers are often incompatible with different models and regions. The aim of the SAE AE-7D committee established in 2018 was to ensure electric aircraft charging didn’t suffer the same fate and benefited from all the lessons learned in the automotive sector.

Synopsis: Batteries need to be tested during R&D and also during the production process to ensure high quality and safety. Batteries store a lot of energy, which needs to be charged and discharged several times during cycling tests. Classical discharging by resistors causes very high energy losses. Energy recovery to grid by individual converters still has certain losses, although they are considerably reduced. A good alternative is Gustav Klein’s Multi-Channel Infeed Testing System. This four-channel testing system allows internal energy recovery, which reduces the losses in power electronics.

Synopsis: Energy density improvement has been seen as the major subject to support hybrid electric aviation. But for the next 10 years, industry-available batteries will hardly be able to double their energy density from their current value. This presentation shows that aviation batteries will need high levels of maturity to comply with safety (and certification) requirements. They will not directly jump from laboratories to aircraft, and safety and economic considerations are at least as important as energy density.

Synopsis: In this presentation Adrian will be presenting Urban Air Port's innovative ground infrastructure developed for electric and hybrid aviation

Synopsis: This presentation outlines how electrification creates value for aircraft design, as well as the limitations of the technology as it relates to resulting aircraft performance. It discusses how electrified propulsion enables novel capabilities using the example of Electra’s super-short takeoff and landing aircraft.

Synopsis: The boosted turbofan is a key concept in the roadmap to more sustainable aviation, and subject to research worldwide. Limited results have been disclosed for this type of parallel hybrid, and most key aspects resulting from the interplay of electric power and gas turbine subsystems remain proprietary to date. This presentation sheds light on the trade-off between weight and efficiency. After introducing the four established concepts of operation for boosted turbofans, we describe the role of shaft speed and gear ratio as key design parameters. We cover physics-based models to quantify trades, and present typical results.

Synopsis: There are 375,000 propeller-driven civilian aircraft in the world today. All use one propeller per shaft. Coaxial contra-rotating propeller (CRP) systems offer considerable performance benefits over single propeller systems. The new 400 HP CRPS 260 GT system provides yaw-free thrust and, driven by powerful electric traction motors, can deliver high-performance STOL capabilities to most aircraft. This new system uses separate motors, batteries and duplicated power electronics to drive the propellers. Furthermore, as a fuselage-mounted unit, it offers ‘twin-engine’ status but, as a coaxial arrangement, without requiring a pilot to hold a twin-engine license rating.

Synopsis: This presentation will offer an assessment and explanation of the synergies between automotive and aerospace e-machine manufacturing as aerospace moves to the requirements for higher volumes of e-machines. The discussion will develop how the system approach to the design of traction e-machines can be applied to aerospace electrification, and will illustrate how the lessons learned from the early years of automotive can be directly applied to the issues of aerospace electrification.

Synopsis: This presentation gives an insight into the work of FutPrInt50, a Horizon 2020 project to identify and develop technologies and configurations that will accelerate the entry into service of hybrid electric regional aircraft in the 50-seat class. The focus will be on promising hybrid electric powertrain architectures, from different approaches to energy storage, conversion and distribution up to the types and arrangement of the propulsors, and the impact of these architectures on the respective aircraft configurations. This will be correlated with the technology roadmap to be put in place to achieve a successful EIS of such regional aircraft by 2035.

Synopsis: The Skybus consortium – made up of GKN Aerospace, Swanson Aviation Consultancy Ltd, Pascall+Watson and the Connected Places Catapult – has been awarded funding to investigate the system of systems needed to realize a large eVTOL concept carrying between 30 and 50 passengers operating over a 20-mile range. The presentation will discuss the various use cases, conops and user profiles, and outline how the project will help you to Mind the Gap.

Synopsis: Verification and validation of the performance and reliability of power electronic systems is critical to the development of more-electric, electric and hybrid aircraft. Ensuring that power quality is maintained in a range of operational and fault conditions is essential, but testing to do so is technically challenging, time-consuming and expensive. Simulation-based validation of power electronic systems is computationally demanding and can take large amounts of time. This presentation describes the use of field-programmable gate arrays (FPGAs) to accelerate power electronic simulation via parallel computation, using tools that only require a basic level of FPGA expertise.

Synopsis: Rolls-Royce has developed the propulsion and distribution system for the CityAirbus demonstrator, an all-electric multicopter designed to demonstrate proof of concept for carrying up to four passengers at a maximum speed of 120km/h. The CityAirbus had its first untethered flight in December 2019 and is currently undergoing a more extensive experimental test campaign. This presentation will update the symposium on the technology and capabilities that can help meet the specific requirements of eVTOL propulsion systems.

Synopsis: This presentation will provide an overview of Varon Vehicles’ vision for urban air mobility, including the systems the company is developing together with multiple partners. It will also describe the potential impacts on transportation services in the Latin American region.

Synopsis: Electric propulsion opens up the design space for flying vehicles, enabling practical electric vertical take-off and landing aircraft through advancements in battery technology, distributed propulsion and control systems development. These technologies are a pathway to sustainable aviation as well novel missions that were not possible or practical before. Only a carefully considered aircraft configuration can satisfy the safety, noise, range and speed requirements of the urban mission envisioned for this type of vehicle. Successful development hinges on innovative technical solutions for the vehicle itself as well as for the tools used for its design. At the same time, the future of electric aircraft relies on fully embracing and advancing the traditional dedication to safety in aviation. Electrification of aircraft presents unique safety challenges as well as new opportunities to tackle them through the potential for increased redundancy, automation and simplified operation.

Synopsis: In this presentation Dr Michael Winter, Senior Fellow for Advanced Technology at Pratt & Whitney, will outline developments that will enable the propulsion of eVTOL aircraft. Advancements in common motors, drives and generators coupled to high efficiency turbines, will accelerate the use of hybrid propulsion across all segments of flight.

Synopsis: This presentation will share with the aerospace community the recent development of an integrated drive system for turboprop hybridization within the EU H2020 CleanSky program. The drive system enables green-taxiing of the turboprop while on the ground with the engine off, and works as a generator when the turboprop is in the air. Some of the key features of the developed system include a high-speed permanent machine (up to 18,000rpm), high power density (11.8kW/L for the power converter, 35.3kW/L and 7.2kW/kg for the machine active parts), integrated cooling design for high-temperature operation (>130ºC ambient temperature) and sensorless control.

Synopsis: Battery systems specialist Electroflight will provide an overview of the technical challenges faced during the design, build and test of a bespoke battery system as part of the Rolls-Royce-led ACCEL project partly funded by the UK government. This will include the key topics of thermal runaway management and cell monitoring, among others. The presentation will explore these themes and the project's findings in the wider context of future commercial applications and the path toward certification.

Synopsis: Air Race E is a world-first all-electric airplane racing series. Eight planes will race wingtip-to-wingtip around an oval circuit at speeds up to 400 km/h (250 mph) around a tight 5km circuit. The development of the airplane is based on a set of formula rules. Open platforms give the possibility to apply different technologies in development of the unique electric powertrain configurations and the race plane. This presentation will describe the challenges the organizers and the teams face as they prepare for the 2022 race series in this innovative and ambitious project.

Synopsis: In this presentation Adrian will be presenting Urban Air Port's innovative ground infrastructure developed for electric and hybrid aviation