Since the beginning of June, Gabriele Sirtori, a postdoctoral researcher at ISA, has been leading a research project aimed at quantifying and attributing operational inefficiencies in air traffic management.

This project, funded by Thales, has the following objectives:

– develop a multidisciplinary operational efficiency metric that takes into account aircraft performance, ATM constraints, and environmental impacts;

– apply this metric to representative pre- and post-COVID periods to quantify and categorize sources of inefficiency, combining economic and environmental indicators with traditional indicators (punctuality, predictability, safety).

In a multidisciplinary team consisting of Laurent Joly and Scott Delbecq (ISAE-SUPAERO) and Xavier Olive (ONERA), this 18-month project will revisit the assessment of inefficiencies in air traffic management, the reduction of which represents a lever for reducing the footprint of air transport.

We look forward to sharing updates on this exciting project.

Melissa Isabell Hofmann is currently immersed in a 6-month end-of-studies internship at the Institute for Sustainable Aviation (ISA) in Toulouse! As a Master’s student in Aerospace Engineering within the double degree program of TUM (Munich) and ISAE-SUPAERO (Toulouse), she is contributing to a significant project on efficiencies in collaboration with Thales AVS and Thales LAS.

Her work, under the supervision of Laurent Joly, Scott Delbecq (ISAE-SUPAERO), and Xavier Olive (ONERA), focuses on the « Horizontal Flight Efficiency Evaluation. » This involves retrieving and recasting flight plans and trajectories for ten carefully selected city pairs (including at least one European Airport). By comparing these with reference trajectories, she will implement robust efficiency metrics for large-scale evaluation. This rigorous approach will enable the identification, quantification, and attribution of both structural and contingent inefficiencies. Excited to have her contribute to advancements in sustainable aviation!

Liquid hydrogen is one of the candidate fuels being considered to power future aircraft with zero in-flight emissions. However, storing it on board—at cryogenic temperatures and under high pressure—poses a major technological challenge. Balancing performance and safety, tank design must ensure structural integrity, thermal insulation, and leak prevention — a critical requirement for the reliability of hydrogen-powered aircraft.
In this context, we are pleased to welcome Ting Hsuan Chen for a six-month internship with the ISA team, under the supervision of Romain Jan (ISA postdoctoral researcher) and Christian Gogu (ISAE-SUPAERO). His project, supported by the Rhyo key challenge and ISA, focuses on designing a cryogenic liquid hydrogen tank capable of withstanding a wide range of loading scenarios, with future certification in mind.
Welcome to Ting Hsuan — his work contributes to the certifiable design of a core component for hydrogen aviation!

« Hydrogen-powered transport aircraft consume less energy than their kerosene-fueled counterparts, regardless of the mission (from short-haul to long-haul flights). »
— D. Brewer, Hydrogen Aircraft Technology, 1991

Today, this claim is challenged by modern scientific literature and a thorough analysis of Brewer’s (NASA) work remains difficult to find.

Since January 2025, Romain JAN’s postdoctoral research aims to critically reassess these findings in light of current certification and aircraft design methodologies.

This project focuses on two main objectives:
– Reducing uncertainty in hydrogen aircraft modeling to enable a fair comparison of their energy performance with kerosene-powered aircraft, considering both conventional and disruptive architectures.
– Assessing the environmental performance of a hydrogen-powered fleet using AEROMAPS, a prospective scenario simulation tool developed at ISA.

Supervised by Professors Jean-Marc Moschetta and Christian Gogu (ISAE-SUPAERO), this research is conducted in collaboration with ENAC and funded by the Institute for Sustainable Aviation and the Rhyo Défi-Clef.

How can air traffic regulation policies contribute to the ecological and social transition?

Launched in November 2024, the PhD research conducted by Thomas Bétous within the ISA aims to study the environmental and social consequences of demand management measures, such as flight quotas or extended stay durations.

This interdisciplinary thesis seeks to combine:

• An assessment of the potential for mitigating the climate impact of commercial aviation for each measure, including the study of possible reactions from sector stakeholders.
• A sociological analysis of air travel and its users, both before and after the implementation of these measures, as well as an evaluation of their social acceptability.

Thomas is supervised by Florian Simatos and Jérôme Fontane from ISAE-SUPAERO, and Yoann Demoli from Clersé / University of Lille. The thesis is co-funded by ADEME and ISA (supported by the Occitanie Region).

Paco Viry, a PhD candidate at the Institute for Sustainable Aviation, presented his research at the TSAS conference in Toulouse. His study, based on 30 years of air operations in North America and 56 different aircraft models, identifies three key factors in aircraft allocation to routes:
– Route length,
– Passenger flow intensity,
– Competition between models within the fleet.

Why does it matter?

Aircraft renewal does not follow a simple logic: an A380 can indirectly compete with a B737-800 through a complex chain of substitutions. Yet, allocation choices have a major impact as fuel consumption per passenger-kilometer can vary significantly, even between aircraft of the same generation. This research, which will contribute to the AeroMAPS platform, aims to better quantify fleet renewal and allocation dynamics to support decision-making for airlines, manufacturers, and regulators.

To read more on the subject :

https://www.researchgate.net/publication/388525725_An_adapted_weighted_multinomial_logit_model_to_capture_the_dynamics_of_global_aircraft-route_assignment