We are happy to share with our network the output of the survey that we launched in February 2021 with the purpose of getting expert opinions on the main perks and drawbacks associated with the deployment of a number of green taxiing techniques analyzed within the project, such as the TaxiBots, the e-Taxi and the Single Engine Taxiing (SET).
As a general consideration, the experts who replied to the survey shared a positive opinion about the solutions taken into account and about their potential of contributing to greener and more sustainable airport operations in the near future. However, the study also revealed that none of the solutions taken into account, per se, is expected to have a radical impact on the sustainability of ground operations.
In particular, Taxibots are considered a very promising solution in terms of fuel consumption, even if potential coordination issues among the actors involved were highlighted in the study as well as issues related to the impact of such solution on surface traffic and to the additional costs implied to potentially upgrade the airport infrastructures. The e-Taxi is considered definitely easier to introduce, as it only impacts the aircraft, even if the additional weight introduced by e-Taxi systems may negatively affect the in-flight performances by increasing the amount of fuel burn per mile, and the airlines might find it less cost-efficient due to the need to install it on every single aircraft. Finally, SET is considered the taxiing technique easiest to be implemented, as already widely diffused among the airlines, but is also the least capable of reducing taxiing operations emissions due to the inefficiency of aircraft turbines during ground movements.
The study clearly points out that the different actors involved (e.g. airlines, ATC, airport) have different opinions about each of the solutions taken into account, due to different costs associated with its introduction both at the technical and operational level.
A systemic approach is thus needed, and also advocated by the experts involved in the study, to combine the use of the different solutions in a comprehensive concept. According to the answers received, such a concept shall be supported by a collaborative decision-making tool able to efficiently allocate the different solutions to the aircraft based on specific characteristics, both static and dynamic, of the fleet and of the traffic.
These results are evidently very encouraging for the AEON project, which aims at reducing the specific inefficiencies of each technology by integrating them into a novel concept of green taxiing operations that will be fed into an airport collaborative tool and support the decision-making of aviation stakeholders. Many experts underlined the impact on the ground traffic of these different solutions. This will be taken into account in the AEON project through specific seamless interactions between the actors to smooth the operations, for instance, speed targets could be computed and passed directly to the drivers. Another option to look further at would be to define dynamically the TaxiBots detach locations to maximize the towed distance and minimize the impact on the rest of the traffic.