Certified Aviation Solutions and Aircraft Integration
A certification-grade energy architecture designed to scale across aircraft programs
In December 2025, H55 completed—for the first time in the aviation industry—all regulator-required and authority-witnessed propulsion battery module certification tests. Conducted under EASA supervision on serial-conforming hardware from approved manufacturing lines, the campaign demonstrated containment of worst-case battery failure scenarios, including thermal runaway without propagation. This established a certification-grade reference framework applicable across multiple aircraft programmes.
H55’s certification approach recognises that thermal runaway is not a random event, but the end state of progressive, measurable cell degradation. As lithium cells age, internal resistance increases, producing detectable shifts in thermal behaviour. In complex serial and parallel battery architectures, pack- or module-level measurements cannot reliably identify degradation at the individual cell level.
H55 therefore designs electric propulsion and Energy Storage Systems with certification embedded from the outset and implements monitoring, protection, and mitigation directly at the cell level. Continuous, flight-relevant monitoring enables early intervention through planned maintenance rather than in-service events.
H55 holds both Design Organisation Approval (DOA) and Production Organisation Approval (POA) for electric propulsion systems, enabling certified design, compliance approval, and serial-conforming production within a single regulator-approved framework.
A regulator-validated reference framework for electric propulsion systems.
H55 organization is certified following aviation standards
Design Organization Approval (DOA)
In 2022, H55 received its Design Organization Approval (DOA) for the development of Electric Propulsion Systems and flight testing, delivered by the European Union Aviation Safety Agency (EASA). An important milestone for the company, illustrating its capabilities in designing and developing EASA compliant aeronautical solutions.
H55 production is certified following aviation standards
Production Organization Approval (POA)
In 2022, H55 received its Production Organization Approval (POA) delivered by the Swiss Federal Office for Civil Aviation (FOCA). The POA is yet another example of the company’s ability to produce aeronautical solutions that ensure quality and performance across the entire product value chain.
Type Certificate
EASA has validated the compliance checklists for H55 Electric Propulsion System (EPS). The EPS includes the Energy Storage System (ESS) and the Electric Propulsion Unit (EPU) within an extended type certificate of the engine under SC-e18.
H55 has assembled a world-class team of certification experts, who are working closely with the regulatory authorities to demonstrate the agreed Type Certification Basis. The initial Type Certificate of the 104 kW EPS will be installed on CS-23 Level 1 aircraft. The first airplanes equipped with the H55 EPS will enter service soon. Following this, H55 will expand its product range, opening the market for CS-23 upper-level normal, utility, and commuter airplanes.
Safety, Security and Quality
H55 has agreed on the safety standards applicable for its EPS with the regulatory authorities. H55 actively supports and participates in aviation authority working groups as to help define a uniform set of standards which the industry and the regulators can align on.
Aircraft Integration
H55 has a proven track record in aircraft integration, with its know-how and experience coming from developing, building and flying 5 aircraft, with nearly over 1600 hours of flying time.
With a seasoned team of integration engineers and technicians, H55 supports its customers with proven knowledge coming from real flight conditions. H55 provides the best optimized solutions for all types of aircraft, lowering the integration factor and ultimately ensuring the best achievable energy density for the aircraft mission.