Sustainable Propulsion/Efficient Aircraft Turbines
The Sustainable Propulsion/Efficient Aircraft Turbines technology trend consists of five subcategories: batteries, efficient aircraft turbines, electric propulsion, hydrogen/fuel cells and sustainable carbon-based fuels.
The most important area in terms of patent family publications is efficient aircraft turbines. The number of patent family publications in this area has increased from 286 in 2000 to 1,200 in 2023 after peaking at 2,115 in 2020 (Figure C21). More efficient aircraft turbines are a key area of research into improving the sustainability of aviation. Important recent developments include the further development of high bypass ratio turbofans, which improve fuel efficiency and reduce emissions. A major advantage of research into more efficient aircraft turbines is that they can make a more rapid contribution to reducing emissions than other more transformative types of Sustainable Propulsion technology, such as electric aircraft, as they can be more easily retrofitted to existing commercial aircraft.
The second most important research area is batteries, where patent family numbers have grown from 34 to 1,322 between 2000 and 2023. Patent family publications in electric propulsion have also risen significantly over the years. Electric planes promise zero emissions, making them ideal for short regional flights and urban air mobility. However, significant progress, especially in battery technology, is essential to enable larger electric aircraft types to fly for more than a very short distances. The main drawback of the current generation of batteries is their weight and low energy density compared to kerosene and hydrogen.
Patent family publications related to the use of hydrogen/fuel cells in aviation have also steadily increased over the last years. Hydrogen aircraft offer a longer-term solution with higher energy density and zero emissions, but also face significant hurdles in terms of infrastructure development and storage complexity. While hydrogen aircraft could be commercially viable for regional and short-haul flights by 2035, widespread adoption for long-haul flights depends on overcoming these challenges and building a global hydrogen infrastructure.
Another challenge for companies is that new more sustainable technologies such as hydrogen- or battery-powered aircraft, must be able to meet the high and complex safety standards in aviation, as safety is so crucial within the sector. Certification is also a challenge considering that for example regulations applicable to electric aircraft are still in the making in most regions.
Patenting activity in the field of sustainable aviation fuel(SAF) increased at the end of the 2000s peaking in 2010 with 115 patent families. After plateauing at this level for a few years, patenting activity declined and did not pick up significantly until 2023 (156 patent family publications). SAF offers a more immediate solution to reducing greenhouse gas emissions than electric or hydrogen-powered aircraft, as the use of SAFs is compatible with existing aircraft and infrastructure. However, SAF is currently more expensive than conventional jet fuel and limited by feedstock availability and production capacity.
Looking at the compound annual growth rates over different time periods, innovation activity was dynamic in all subcategories between 2000 and 2019, but growth rates have been mixed from 2020 onward (Figures C22–C24). While the number of patent families in hydrogen/fuel cells and sustainable fuels continues to grow dynamically, patenting activity in efficient aircraft turbines and electric propulsion has decreased significantly (Figure C22).
Figure C25 shows that US inventors are still responsible for most patent family publications, but China is catching up owing to having much higher growth rate. In addition, RSI values show that France and the United Kingdom have the highest degree of specialization in Sustainable Propulsion/Efficient Aircraft Turbines, mainly due to the research activities of Safran and Airbus in France and Rolls-Royce in the United Kingdom.
Looking more closely at RSI values over different time periods, the high degree of specialization in France is once again highlighted (Figure C26). Other highly specialised countries are the United Kingdom, Canada, the United States, Spain and Germany. Spain, in particular, has significantly increased its RSI in Sustainable Propulsion/efficient aircraft engines over the years.
Analysis of the top research countries in the different subgroups of Sustainable Propulsion/efficient aircraft turbines provides the following key results (Figure C27):
The United States is the technology leader in efficient aircraft turbines with more than 12,000 patent families published between 2000 and 2023. France and China follow at a considerable distance in second and third place.
China is leveraging its technological leadership and know-how in battery technologies into aviation. With more than 5,000 patent family publications since 2000, the country is clearly in the lead, ahead of the United States and the Republic of Korea.
Electric propulsion research in aviation is dominated by China and the United States.
The United States, Germany and China are the top three research nations for hydrogen/fuel cell research in aviation.
The United States leads in the research and development of sustainable aviation fuels.
RTX, GE, Safran, Rolls-Royce and Airbus are the top research companies in Sustainable Propulsion/Efficient Aircraft Turbines in terms of patent family publications. Being aerospace companies, they all have very high RSI scores (Figure C28).
However, patent family publications have declined since 2018 for most of the top applicants. Only Airbus and Aero Engine Corporation of China (AECC) have grown their patent portfolios since 2018. AECC in particular stands out, with an average patent growth rate of more than 160% per year over the last five years.
Regarding the top patent owners in the five subgroups, the following results can be stated (Figure C29):
Airbus is a research leader in batteries, electric propulsion, hydrogen and fuel cells and SAFs. An example is the E-Fan X project where Airbus together with Siemens and Rolls Royce developed a hybrid-electric aircraft demonstrator, in which one of the jet engines on a BAe 146 test aircraft was replaced with a 2 MW electric motor.
(4)Airbus. E-Fan X: A giant leap towards decarbonising flight. Available at: www.airbus.com/en/innovation/low-carbon-aviation/hybrid-and-electric-flight/e-fan-x. Another example is EcoPulse, a distributed hybrid-propulsion demonstrator aircraft, developed in partnership with Daher and Safran. Airbus is contributing battery technology and aerodynamic modelling to the project.(5)Airbus. EcoPulse: A new approach to distributed propulsion for aircraft. Available at: www.airbus.com/en/innovation/low-carbon-aviation/hybrid-and-electric-flight/ecopulse. The ZEROe project by Airbus focuses on hydrogen powered aircraft concepts.(6)Airbus. ZEROe: Towards the world’s first hydrogen-powered commercial aircraft. Available at: www.airbus.com/en/innovation/low-carbon-aviation/hydrogen/zeroe. The goal is to bring a hydrogen-powered plane to market by 2035.Boeing and its subsidiary Aurora Flight Sciences are cooperating with GE and NASA on the development of a hybrid electric engine to power a single aisle aircraft.
(7)GE Aerospace (2022). Electric skies: Boeing joins GE and NASA’s hybrid electric flight project: Available at: www.geaerospace.com/news/articles/sustainability-technology/electric-skies-boeing-joins-ge-and-nasas-hybrid-electric-flight. The company and its subsidiary, Wisk, are also developing uncrewed passenger-carrying urban air mobility operations using eVTOLS.(8)Boeing Future of Flight. Air taxi by Wisk. Available at: www.boeingfutureofflight.com/wisk. Shell is a research leader in sustainable fuels. The company is currently building a 820,000-tons-a-year biofuels facility in Rotterdam to produce sustainable aviation fuel (SAF) and renewable diesel made from waste.
(9)S&P Global (2023). Shell to deliver first SAF from Rotterdam plant from 2025. Available at: www.spglobal.com/commodityinsights/en/market-insights/latest-news/agriculture/050323-shell-to-deliver-first-saf-from-rotterdam-plant-from-2025. RTX is the leader in research on more efficient aircraft turbines. For example, Pratt and Whitney, a subsidiary of RTX, announced in 2023 it had to have developed a patent-pending new technology for calculating turbine thrust using lasers to enable the high-fidelity measurement of key parameters including velocity, temperature and density.
(10)PR Newswire (2023). Pratt & Whitney and Virginia Tech pioneer laser-optical thrust and emissions measurement for gas turbines. Available at: www.prnewswire.com/news-releases/pratt--whitney-and-virginia-tech-pioneer-laser-optical-thrust-and-emissions-measurement-for-gas-turbines-301851939.html.
Automation and Circularity
Automation and Circularity technologies in the air transport field include the areas of smart production, efficient material use and recycling.
Smart production is the major research area within Automation and Circularity. The number of patent family publications in this technology area has increased from only 75 in 2000 to almost 2,100 in 2023 after having reached an even higher peak of 2,442 in 2021 (Figure C30). Smart production is transforming aviation by incorporating advanced technologies such as automation, AI and IoT into manufacturing processes, so as to increase efficiency, reduce costs and improve product quality.
Patent family publications in the field of efficient material use have risen from only 3 in 2000 to 175 in 2023. Efficient material use in aviation is crucial for enhancing performance, reducing costs and minimizing environmental impact. Key research developments focus on lightweight composite materials that offer high strength-to-weight ratios, such as carbon fiber-reinforced polymers, leading to improved fuel efficiency and reduced emissions.
The number of patent family publications related to recycling in air transport remains low. In 2023, only 37 patent families were published. Nonetheless, aircraft recycling is crucial for sustainable aviation, potentially reducing the industry's environmental impact by minimizing waste generation and lowering the overall carbon footprint. Key research and development efforts focus on innovative methods for recycling the composites and metals used in aircraft structures, including advanced processes for reusing carbon fibre composites and efficient methods for recovering and reusing aluminium and titanium. However, recycled materials require extensive testing and certification in order to meet stringent regulatory standards before they can be used again for aircraft production, which can be prohibitively expensive and time-consuming.
Patent growth in Automation and Circularity technologies was very dynamic in all subgroups between 2000 and 2019 (Figures C31–C33). However, from 2020 onward, patent growth has been negative in smart production and efficient material use (Figure C31). Only patent family publications in recycling have continued to grow in recent years, albeit from a low level.
A country comparison shows that China is ahead in Automation and Circularity research activities in terms of total patent family publications (Figure C34). However, patent growth has been the highest in the Republic of Korea since 2018. In contrast, patenting activity has declined substantially in Australia and the United Kingdom.
RSI values show that France, the United States, India and Spain have the highest degree of specialization in Automation and Circularity technologies. Japan is clearly below average in terms of specialization in this area.
The evolution of RSI values over different time periods since 2000 shows that France's high specialization in Automation and Circularity technologies has remained relatively constant through the years (Figure C35).
Analysis of the top research countries in the different subgroups of Automation and Circularity technologies provides the following key results (Figure C36).
China is the clear technology leader in smart production with more than 10,600 patent family publications. The country has more than twice as many patent family publications as the second-ranked the United States (3,842).
However, the United States has developed the most patent families in the research field of efficient use of materials. China, Germany and France are also important players in this field.
China, the United States, the Republic of Korea and Japan are at the forefront of research on recycling in air transport. However, the number of patent family publications remains relatively modest in all these countries.
Boeing (1,000 patent family publications between 2000 and 2023), Chinese drone-maker DJI (536), Airbus (476) and RTX (467) are the top research companies in Automation and Circularity technologies in terms of patent family publications (Figure C37). All of these companies have a very high RSI score.
Some companies whose main business focus lies in other industries such as Panasonic also play a relevant role in Automation and Circularity research in air transport. As a consequence, the RSI score of Panasonic is much lower.
In terms of growth rates, the Chinese Northwestern Polytechnical University stands out among the top 10 patent owners, with an annual growth rate in patent family publications of more than 14% since 2018.
With regard to the top patent owners in the three sub-groups of Automation and Circularity technologies, the following results and research examples can be noted (Figure C38):
Boeing is an innovator in smart production technologies with almost 850 published patent families in this field. For example, this US aircraft manufacturer is using AI-powered robots on its assembly line to automate tasks like drilling, painting and assembly in order to reduce cycle times and enhance productivity.
(14)Linköping University (2018). Materials for more efficient aviation. Available at: https://liu.se/en/news-item/material-for-ett-effektivare-flyg. Airbus also has published many patent families both in smart production and efficient material use. Airbus is also active in recycling. In 2022, the company initiated the European research project, HELACS (Holistic processes for the cost-effective and sustainable management of End of Life of Aircraft Composite Structures) that focuses on the dismantling and recycling of large composite structures.
(15)Airbus (2022). End-of-life Reusing, recycling, rethinking. Available at: https://aircraft.airbus.com/en/newsroom/news/2022-11-end-of-life-reusing-recycling-rethinking. Almost all of DJI’s patent families in Automation and Circularity technologies belong to the area of smart production. DJI’s drones can be used to better detect manufacturing irregularities or deviations, so as to improve quality control and reduce downtime.
(16)DJI Enterprise (2021). DJI Enterprise's complete guide to drone inspections based on best use cases. Available at: https://enterprise-insights.dji.com/blog/complete-guide-to-drone-inspections. RTX is the research leader in efficient material use with almost 230 published patent families since 2000. RTX focuses on the development of advanced materials and manufacturing techniques that enhance performance while reducing resource consumption. For example, RTX is leveraging additive manufacturing to optimize designs, shorten production times and produce parts on-demand, thereby minimizing material waste.
(17)RTX (2023). RTX's Collins Aerospace business opens $14 million additive manufacturing center expansion in West Des Moines, Iowa. Available at: www.rtx.com/news/news-center/2023/07/21/rtxs-collins-aerospace-business-opens-14-million-additive-manufacturing-center.
Communication and Security
Communication and Security technologies in the air transport field include navigation technologies, low-latency-communication, device-to-device communication, cloud solutions and cybersecurity technologies.
The most important area in terms of patent family publications is clearly navigation technologies. The number of patent family publications in this technology area has increased fifteen-fold from 466 in 2000 to almost 7,300 in 2023 after reaching an even higher peak of 7,800 in 2021(Figure C39). Aviation navigation technologies have evolved significantly over the past decades, improving the safety, efficiency and reliability of aviation. For example, global positioning system (GPS) technology has been enhanced through the integration of multiple satellite navigation systems such as GLONASS, Galileo and BeiDou.
The second most important research area is low-latency-communication, where patent family numbers have grown from less than 200 to around 1,200 between 2000 and 2023. Low latency communication is integral to the effectiveness and safety of navigation technologies in aviation, facilitating real-time data exchange. For example, low latency communication ensures that information between pilots and air traffic controllers is exchanged in real-time and allows for immediate updates and corrections to flight paths, which is crucial during critical phases of flight such as takeoff and, landing, and during adverse weather conditions. The rollout of 5G networks provides significantly lower latency than previous generations of mobile networks, benefiting aviation, where it can enhance communication between ground systems and aircraft. Advances in satellite communications, including low Earth orbit (LEO) satellites, are reducing latency and improving global coverage, which is particularly beneficial for remote and over-ocean flight operations.
Patent family publications for device-to-device technologies in aviation have also increased significantly to over 700 in 2023. Device-to-device communication in aviation plays a pivotal role in enhancing the efficiency, safety and reliability of air transport operations. Key developments include the integration of technologies such as Automatic Dependent Surveillance-Broadcast (ADS-B), which enables aircraft to broadcast their position, velocity, and other critical data directly to other aircraft and ground stations. This real-time sharing of information enhances collision avoidance, optimizes flight paths and improves air traffic management. D2D communication also supports more efficient and safer formation flying and swarming tactics for military and unmanned aerial vehicles (UAVs).
Patent family publications for cloud technologies in air transport increased to around 650 in 2023. Cloud computing enables airlines to store and process vast amounts of data in real time, enabling more informed decision making. For example, predictive maintenance uses cloud-based data analytics to monitor aircraft health and predict potential failures before they occur, thereby reducing downtime and maintenance costs. In addition, cloud technology enables seamless communication and data sharing between different stakeholders, including airlines, airports and air traffic control.
The smallest research area in terms of patent family publications is cybersecurity in air transport. Patent activity has increased only moderately from 4 in 2000 to around 100 in 2023. Nevertheless, cybersecurity plays a critical role owing to the adoption of technologies like cloud computing and advanced navigation and communication systems that expose aviation infrastructure to a wide range of potential cyber threats.
Looking at the compound annual growth rates of patent family publications over different time periods, a clear picture emerges. Innovation activity was dynamic in all subcategories between 2000 and 2019, but growth rates have slowed down and even been negative in some technology areas from 2020 onward (Figures C40–C42).
A country comparison in the field of Communication and Security technologies shows that China has become responsible for most patent family publications thanks to very high innovation dynamics (Figure C43). The Republic of Korea and Italy have also achieved high growth rates over recent years.
RSI values show France, Israel and the United States having the highest degree of specialization in Communication and Security technologies. Italy and Japan are below average in terms of specialization in Communication and Security technologies.
The evolution of RSI values over different time periods since 2000 shows that France's high specialization in Communication and Security technologies decreased from 0.6 between 2000 and 2010 to 0.4 between 2020 and 2023 (Figure C44).
The analysis of the top research countries in the different subgroups of Communication and Security technologies provides the following key results (Figure C45):
China is the technology leader in navigation and cloud technologies in terms of total patent family publications.
The United States is ahead in device-to-device communication and cybersecurity.
China and the United States are at an equal level in low-latency-communication research activities.
Other key research countries include Japan, the Republic of Korea, Germany and France.
Boeing (2,165 patent family publications between 2000 and 2023), Airbus (1,621), Honeywell (1,453), RTX (1,283), DJI (1,279) and Thales (1,100) are the top research companies in Communication and Security technologies in terms of patent family publications (Figure C46). All of these companies have a very high RSI score. The four Chinese research organizations Beihang University, Nanjing University of Aeronautics and Astronautics, Northwestern Polytechnical University and the Chinese Academy of Sciences have also developed large patent portfolios in Communication and Security technologies.
In terms of growth rates, all four of the aforementioned Chinese research institutions have achieved high patent growth rates since 2018. In contrast, the patenting activity of the top research enterprises has declined over the same period, the only exception being RTX, which has maintained its patenting activity at a constant level.
With regard to the top patent owners in the five sub-groups, the following results and research examples can be noted (Figure C47):
Boeing is a top researcher in all Communication and Security technologies. Boeing's lead is particularly strong in device-to-device communication, with 315 patent family publications since 2000 (almost twice as many as Honeywell, which ranks second with 159).
Chinese drone maker DJI is mainly pursuing research projects in navigation technologies. DJI is advancing autonomous navigation, enabling drones to operate without human intervention. This involves integrating sensors, cameras and algorithms to navigate and respond to their environment.
Airbus is very active in research and development of navigation technologies. For example, Airbus is developing the new V3 generation of the satellite-based augmentation system EGNOS (European Geostationary Navigation Overlay Service) The EGNOS V3 is designed to add crucial security features for applications such as aircraft navigation and landing.
(24)Airbus (2022). Airbus achieves key milestone on EGNOS European satellite-based navigation augmentation system. Available at: www.airbus.com/en/newsroom/press-releases/2022-12-airbus-achieves-key-milestone-on-egnos-european-satellite-based. It will also introduce new services based on multiple frequencies from multiple constellations (GPS, Galileo).Honeywell is also a leading research company in all Communication and Security technologies. For example, this US company provides hardware and software systems for aircraft that use security measures to provide multifactor authentication, encryption and data integrity.
(25)Honeywell Aerospace Technologies. Aerospace cybersecurity solutions. Available at: https://aerospace.honeywell.com/us/en/products-and-services/product/services/aerospace-cybersecurity-solutions.
Human–Machine Interface
Human–Machine Interface (HMI) technologies in the air transport field include the areas VR/AR/metaverse, Touch Display/Data gloves, Face recognition, Speech recognition and Head-up-displays.
VR/AR/metaverse has become the most important subgroup of HMI technologies in Air transport in recent years. The number of patent family publications in this technology area has increased from only 23 in 2000 to more than 350 in 2023 (Figure C48). The integration of VR/AR/metaverse in aviation improves training, operations and maintenance. Recent research focuses on the development of virtual training environments for pilots and maintenance crews, providing realistic simulations that improve skills and safety without the risks associated with real-life training.
The number of patent families published in the area of touch displays/data gloves has increased from 27 in 2000 to 226 in 2023. Advanced touchscreens streamline cockpit operations by consolidating multiple control functions into a single, intuitive interface, thereby improving efficiency and reducing pilot workload. Meanwhile, haptic-feedback data gloves provide tactile sensations for virtual objects, aiding remote training.
Facial recognition patent families have increased from only 2 in 2000 to more than 150 in 2023. Facial recognition technology enhances security, streamlines passenger processing and improves the overall travel experience. Airports are increasingly using facial recognition systems for tasks such as check-in, boarding and security screening.
The number of patent family publications for speech recognition in air transport remains has risen from 14 in 2000 to 99 in 2023. Recent advances have focused on improving automatic speech recognition (ASR) systems for air traffic control and pilot interaction. Moreover, speech recognition can significantly speed up inspections and maintenance operations. Ground crew teams can perform external aircraft inspections hands-free, simply using their voice to capture observations and record data.
The number of patent families published for aviation head-up displays has increased from 21 in 2000 to 83 in 2023. These displays project essential flight data and navigation information onto a transparent screen in the pilot's line of sight, allowing the pilot to maintain focus outside the cockpit while accessing critical information. Used for decades by military pilots, head-up displays are now commonplace in large commercial and private aircraft.
Patent growth in HMI technologies was very dynamic in all subgroups between 2000 and 2019. However, from 2020 onward, patent growth has been negative in all HMI technologies except VR/AR/metaverse (Figures C49–C51).
A country comparison in the field of HMI technologies shows that the United States is the leading country in terms of sheer volume of patent publications. However, patenting activity has declined in most countries in since 2018 (Figure C52). Patent family publications have only risen slightly in the Republic of Korea and Germany.
RSI values show that France, India and the United States have the highest degree of specialization in HMI technologies. Japan and China are well below average in terms of specialization in this area.
The evolution of RSI values over different time periods since 2000 shows that India and the United States have significantly increased their research focus on HMI technologies in relative terms over time (Figure C53). In addition, France has kept a high level of research specialization in these technologies since 2000.
An analysis of the top research countries in the different subgroups of HMI technologies reveals the following key findings (Figure C54):
The United States is the research leader in all five HMI technologies. The United States lead is particularly strongly in respect to head-up displays.
China is catching up in most HMI technologies. It is particularly dominant in speech recognition, publishing almost as many patent families as the United States.
The Republic of Korea is especially active in VR/AR/metaverse research.
France has developed the second most patent families in head-up displays.
Honeywell (372 patent family publications between 2000 and 2023), RTX (302) and Thales (266) are the top research companies in HMI technologies in terms of patent family publications (Figure C55). All of these companies have a very high RSI score.
Some companies whose main business focus is in other industries, such as Panasonic, also play a relevant role in HMI research in aviation. As a result, Panasonic's RSI score is much lower.
In terms of growth rates, RTX stands out among the top patent owners, being the one company with a positive patent growth rate since 2018.
With regard to the top patent owners in the five sub-groups of HMI technologies, the following results and research examples can be noted (Figure C56):
DJI is an innovator in facial recognition and AR/VR/metaverse technologies. For example, DJI's Virtual Flight app and VR headsets allow drone pilots to practice at home or the office before taking off a real drone.
(30)Radiant Vision Systems (2021). Safety in the air: The latest in aviation head-up displays (HUDs). Available at: www.radiantvisionsystems.com/blog/safety-air-latest-aviation-head-displays-huds. Honeywell is a key research company in speech recognition, touch displays and data gloves and head-up-displays. The company acquired Saab Technology, the head-up-display division of Swedish aerospace and defense company Saab, in 2023. It has integrated head-up-displays into its various avionics offerings, for example into its new modular flight deck Anthem which also incorporates touch displays as well as gesture-based methods.
(31)Honeywell (2023). Honeywell bringing heads-up displays to aircraft cockpits through acquisition of Saab Technology. Available at: www.honeywell.com/us/en/press/2023/06/honeywell-bringing-heads-up-displays-to-aircraft-cockpits-through-acquisition-of-saab-technology. (32)Honeywell Aerospace Technologies. Your cockpit, your way with Honeywell Anthem. Available at: https://aerospace.honeywell.com/us/en/about-us/blogs/your-cockpit-your-way-honeywell-anthem.
