In order to meet the increasing demand to reduce fuel consumption, Green House Gas emissions as well as operating and maintenance costs, while optimising aircraft performances, fuel cell systems are considered as one of the best options for efficient power generation systems in the context of more electric aircraft (MEA).

FLHYSAFE’s ambition is thus to demonstrate that a cost efficient modular fuel cell system can replace the most critical safety systems and be used as an emergency power unit (EPU) aboard a commercial airplane providing enhanced safety functionalities.

Additionally, the project will virtually demonstrate that the system is able to be integrated into current aircraft designs respecting both installation volumes and maintenance constraints.

In order to shift from demonstrator levels (achieved in other projects), to the ready-to-certify product level, it is necessary to optimise the different components of the fuel cell system to reduce its weight, increase its lifetime, ensure its reliability, certify its safety and make its costs compatible with market requirements.

FLHYSAFE will propose fuel cell technologies using PEM (Proton Exchange Membrane) fuel cell stacks, more integrated power converters and air bearing compressors. Thanks to the experience of the participants in previous projects, the necessary tests will be carried out in order to demonstrate compatibility to representative environment and safety levels.

To ensure a smooth transition to exploitation, including certification, FLHYSAFE‘s objective is to conclude the project with a maturity level of TRL 5 for the components of the sub-system, and partially TRL 6 at system level starting with available technologies at TRL 3 and TRL 4.


The work and achievements of FLHYSAFE are
expected to have significant impact on several levels:


Transport is one of the main areas where fuel cell and hydrogen is bringing an enormous added value by replacing fossil energy by electricity eliminating GHG emissions.

Road transport is already deploying the technology and other areas such as maritime (including submarine applications) have largely experienced the technology.

The aeronautic industry is still behind as a very stringent safety and weight are additional critical issues to take into account. The few demonstrations already made showed it was feasible to now move to deployment. Reliability, performance, lifetime, safety and cost must be addressed to convince the market to adopt the technology.

FLHYSAFE expects to strongly contribute to this market objective as the impact will be very important. First, for the adoption of the technology, if FCH technologies fly with measurable results in terms of emission reductions, noise reduction especially on the ground, safety, efficiency and cost, with significant applications such as an EPU, the demonstration will also be important to convince adoption in less demanding sectors. Secondly, the aeronautic industry will provide a large market for FCH technologies: according to Airbus, 37 400 (to Boeing, 42 730) new aircraft will be required in the next 20 years. Adding the potential retrofit market, this will be a significant market for installation and use.


Fuel cells are a promising solution for generating electrical power on aircraft, providing solution to minimise the environmental impact and providing new ways of producing decentralised energy.

FLHYSAFE has fixed its environmental impact objectives according to the use of a life-cycle assessment methodology to assess potential environmental impacts associated with all the stages of the FC system life cycle (from material through manufacture, distribution, use, repair and maintenance, and disposal or recycling). A general analysis will be refined in the project and evaluated according to measures obtained when performing tests. If the first application (EPU) has limited saving possibilities when replacing the RAT, the other applications targeted by the FLHYSAFE partners – cabin/hotel loads and APU – have much important capabilities.


One of the most key objectives of the development roadmap of the aeronautic industry for 2020 to 2050 is the reduction of emission – CO2, NOx, SOx and particulates – with a focus on electrical power supply obtained from renewable energies.

Fuel Cells are outlined as one of the technologies to deliver on-board electrical energy and in particular an e-APU independent of the aircraft engines. Fuel cells technology will require for that “an extraordinary technological effort to define air vehicle systems of the future that minimise environmental impact and energy consumption”.

FLHYSAFE is looking to several corresponding objectives outlined in these roadmaps. In particular FLHYSAFE will be a major contributor to the topic Sustainable energy regarding Fully on-board electrical energy by 2035 as part of the ACARE SRIA Challenge 3 – Protecting the environment and the energy supply according to the following development path (target is EIS by 2026) which is dependent of:

  • The development of new aircraft able to incorporate on board fuel cell systems (probably around 2030)
  • Standardisation aspects (that may slow down the path)
  • Certification and corresponding regulations (that may as well slow down the path)
  • Environmental regulations at the airport level (that may accelerate the path is more stringent regulations are adopted).