The Transatlantic Strategic Aviation Partnership (TSAP) is a global forum of government officials and academic leaders, primarily based in the US, UK, and EU, dedicated to shaping the future of aviation. The partnership is convened jointly by the MIT Laboratory for Aviation and the Environment and the University of Cambridge’s Aviation Impact Accelerator. The partnership’s goal is to identify and deliver opportunities for transatlantic collaboration to raise ambition on developing the aviation sector to best serve societies.

The first TSAP event was an inaugural workshop hosted by MIT in Boston, Massachusetts in 2023. The workshop identified four key goals needed by the aviation sector over the next five years. These were further developed through discussions with industry, policymakers and other academics and resulted in a report ‘Five years to chart a new future for aviation’.

The 2025 workshop

The second TSAP workshop was held in Cambridge, UK in April 2025, at the Cambridge Institute for Sustainability Leadership and the Whittle Laboratory. Over the course of two days, participants evaluated the development trajectories of the aviation sector to identify common understandings of how aviation can best serve economies and societies and identify actions to achieve long-term goals.

Participants began by identifying and ranking the key drivers and strategic objectives which are expected to influence aviation through to 2075. Technological and operational levers were identified which can shape the industry and were subsequently evaluated. Participants then worked backwards to identify and prioritise areas of focus and define key milestones to enable a positive trajectory for the sector under the outlined objectives. Four priority areas of focus were highlighted along with core recommendations for action. These are summarised below.

Note: The outputs of the event as outlined here do not necessarily reflect the policies or views of any of the participating individuals or organisations. The documentation below is the responsibility of the workshop organisers and reflect their take-aways.

Priority area 1: Cryogenic fuels (especially methane and hydrogen)  

Sustainable Aviation Fuels (SAF) will play a key role in aviation’s near-term transition to new energy carriers. However, SAF is unlikely to reach sufficient scale as a solution for the entire sector. This is due to two main factors: the global supply of biomass is highly unlikely to meet the demands of different sectors, and synthetic fuels are likely to remain significantly more expensive than fossil fuels and biomass-based SAF. In the absence of transformative breakthroughs in battery technologies, aviation would therefore face a strategic decision between two primary pathways:

  • Eliminating carbon from its energy supply, such as through using cryogenic liquid hydrogen, or
  • Retaining carbon by choosing a lower-cost, lower-energy fuel pathway that offers a simpler transition, such as cryogenic methane.

Among the various non-drop-in fuel options discussed during the workshop, hydrogen and methane emerged as the leading candidates for implementation, based on their respective technical advantages and environmental benefits. Both options require new aircraft and infrastructure but differ in cost and complexity. Participants in this workshop highlighted the need for a comprehensive, system-level assessment of the practicality, cost, and interplay of both pathways, and the factors involved in transition. Such a study would identify opportunities for transatlantic leadership.

Recommendation 1: Conduct a transatlantic study on the feasibility and economic prospects of using methane and hydrogen as aviation fuels (relative to fossil fuels and SAF).

The study would identify the options for innovation on non-drop-in fuels and systematically compare the two candidates (methane and hydrogen). The study would further evaluate whether other energy carriers offer potential for consideration in such a system-level assessment.

The study would be conducted for different segments of the aviation market (such as different market distances, payloads, etc.). The following criteria are proposed:

  • Technical considerations:
    • Safety and certification case
    • How to prepare airport infrastructure, including additional infrastructure development requirements
    • The total greenhouse gas emissions of the different fuels across the value chain
    • Leakage risks
  • Economics and availability of fuels:
    • Availability of feedstocks and  comparison between viable fuel production pathwaysInfrastructure requirements for airports and fuel distribution networks
    • Aircraft technology development
  • Intersections with other objectives of the aviation sector:
    • Climate impacts, including non-CO2
    • Local air quality
    • Job opportunities
    • Energy security

Priority area 2: Air Traffic Control efficiency and contrail avoidance

Modernising airspace could significantly reduce operational inefficiencies in today’s air transportation system by 5–10 per cent (as measured in global fuel burn), according to ICAO. This can be achieved by the elimination of horizontal, vertical and speed inefficiencies caused by fragmented airspace structures, uncoordinated flight planning, conservative airspace management, and congestion. Modernising airspace and its management would not only improve economic efficiency but also help address current safety and staffing challenges.

In addition, airspace modernisation could enable the elimination of contrails – the clouds formed by aircraft – which may be a significant contributor to the atmospheric impacts of air transportation. Operational contrail avoidance would require enhanced control to deviate flight paths (typically vertically) seeking a route where contrails do not form and persist.

The workshop identified a need for focused analysis of the combined benefits of modernising air traffic control and implementing operational contrail avoidance. While contrail avoidance depends on improved atmospheric observation and forecasting capabilities, participants also identified an opportunity to focus on understanding the broader opportunities and synergies offered by airspace modernisation.

Recommendation 2: Conduct a transatlantic assessment of the potential benefits of airspace modernisation.

The assessment would provide global leadership in re-thinking today’s foundational principles of airspace. Such an assessment would aim to help improve airspace capacity, safety and efficiency. The following goals were proposed:

  • Technical assessment of how to enable increased flexibility while maintaining or improving safety levels
  • Identify and quantify the benefits of airspace modernisation including fuel burn benefits, CO2 reduction, contrail mitigation, capacity increases, and safety
  • Assessment of the costs of implementation

Recommendation 3: Design and implement early field trials of air traffic control flexibility.

Based on the results of the systems assessment outlined in Recommendation 2, opportunities for early experimentation can be identified. Transatlantic routes potentially provide a prime testing ground. As such, research is needed to support transatlantic trials which aims to:

  • Demonstrate the feasibility of vertical flexibility
  • Evaluate how capacity constraints intersect with contrail mitigation
  • Assess interaction between fuel efficiency benefits and contrail mitigation
  • Observe, measure, and verify contrail impacts and evaluate airspace-level implications of contrail mitigation at scale
  • Inform recommendations for contrail mitigation policies

Priority area 3: Innovative business models for air transportation

Disruptive innovation in the aviation sector requires an understanding of the underlying business model. The market is currently shaped by a small number of established stakeholders in the transatlantic region. This has resulted in the delivery of incremental improvements, rather than disruptive innovation. In addition, technical and economic regulations of air transportation markets, as well as certification requirements, pose significant barriers for new entrants and innovative disruptors. As a result, the sector may lack the necessary incentives to foster disruptive innovation. This gap may undermine the ongoing leadership of the transatlantic partners. Rising fuel costs, environmental pressures, and competition from other regions may challenge the status quo and create the conditions for disruptors to enter.

The group highlighted a significant research gap in this area and stressed the need to explore how disruptive innovation can be fostered and how new business models could evolve to accelerate innovation.

Recommendation 4: Understand the business model for disruptive innovation in the air transportation sector.

The study would take a comprehensive view of the stakeholders in the aviation value chain and their underlying drivers and inhibitors of innovation. It would further identify the conditions which would lead to dramatic acceleration of innovation in the sector. Such considerations would include assessments of:

  • Barriers to entry for newcomers
  • Impact on incumbent sectoral leaders
  • Approaches to stimulate revolutionary, not just incremental, technological and business model innovation, including lessons from other sectors
  • New modes of collaboration across academia, industry and governments and across the Atlantic (such as through high-reward exploratory ‘moonshot’ programmes)
  • The role of governments to move revolutionary aviation technologies towards prototyping and production at scale
  • Comparisons to successful transformations in other sectors

Priority area 4: Carbon removals

In assessing the prospect of SAF and other energy carriers, participants discussed the degree to which non-fossil-based fuels can meet decarbonisation goals for the air transportation sector. Considering cost and availability concerns for such non-fossil-based fuels, especially in the short- and medium-term, carbon removals were identified as a critical area of study – not just for the aviation sector, but for the whole economy. A diverse set of carbon removal technologies are under development, including Direct Air Capture (DAC) of atmospheric CO2, Bioenergy with Carbon Capture and Sequestration (BECCS), and marine or biochar sequestration.  Participants identified a need for a comparison of these technologies as they apply to the aviation sector, covering cost, practicality, technological readiness and accurate monitoring and auditing. This comparison should include a cross-sector perspective, and consider regulatory, market and economic consequences.

Recommendation 5: Conduct a feasibility study on the role of carbon removals in the aviation industry, including considering continued use of fossil fuels.

The study would evaluate a range of carbon removal technologies, expanding out from commonly discussed approaches such as DAC and BECCS, and would take a cross-sector perspective. The following evaluation criteria were proposed for the study:

  • Technical feasibility:
    • Technology readiness and scale-up potential of each technology
    • Storage capacity and associated permanence risks
    • Comparison to, and synergy with, carbon utilisation options such as biofuels and Power-to-Liquid fuels
  • Economic considerations:
    • Comparison of costs, risks, and uncertainties of different technologies
    • Synergies with economic transitions and workforce opportunities in oil and gas sectors Impact of future costs of fossil fuels
  • Environmental and resource considerations:
    • Resource requirements and competing demand, such as for electricity or waste heat
    • Comparison to, and synergy with, carbon utilisation options such as biofuels and Power-to-Liquid fuels
  • Policy needs:
    • Existing and future policy needs to incentivise carbon removals
    • Interaction with other policies such as SAF mandates and CORSIA
    • Trust, verification and monitoring of removals

Glossary of terms:

Biochar: A charcoal-like substance made by heating organic material at high temperatures in the presence of little oxygen.

Contrail mitigation: Strategies aimed at reducing or avoiding the formation of contrails, which can contribute to atmospheric warming.

CORSIA: Carbon Offsetting and Reduction Scheme for International Aviation.

Cryogenic: Refers to storage at extremely low temperatures

Energy carriers: Substances (such as fuels) that contain energy and can be converted to other types of energy.

Moonshot programmes: Highly ambitious and exploratory initiatives aimed at achieving breakthrough innovation.

Non-drop-in fuels: Fuels that require new aircraft and infrastructure rather than being compatible with existing systems.

Power-to-Liquid fuels: Synthetic fuels created by combining hydrogen produced by renewable electricity with carbon dioxide.