Thesing Software & Security Consulting GmbH

Certification / Airworthiness

Using a manned aircraft or (larger) drone (Unmanned Arial System, UAS) is only permitted when the drone or A/C has been certified by an airworthiness authority. Which authority is responsible depends on the class of A/C or drone:

Civil manned A/C in the EU are regulated by the European Union Aviation Safety Agency (EASA)
UAS for civil use are handled by the national airworthiness authority and EASA (for operation in the EU)
Military and governmental (e.g., police) A/C are handled by national military authorities

A central concept is that the A/C is to be airworthy, i.e., build according to its design and in a safe operation condition. For the design, the airworthiness department of the design organisations make sure that the design constraints ensuring an airworthy design are satisfied.

At TSSC we have worked in the certification of A/C and propulsion systems both in civil and military settings and can support you in your certification endeavour.

Civil Manned Aviation

Based on the United Nations International Civil Aviation Organization (ICAO) agreements, authorities must exist that ensure safe design of aircraft. For the EU, EASA has been assigned this role by European regulation EU 2018/1139 (Basic Regulation). The procedures for design, production and other airworthiness tasks are laid down in EU regulation 748/2012, also called Part 21.

Part 21 defines that a product (A/C, engine or propeller) needs a Type Certificate (TC) so that the design can be considered airworthy. A TC needs to be applied for to EASA and only organisations that hold a Design Organisation Approval (DOA) from EASA can do so. The process of obtaining a TC includes showing compliance of the product to the certification specifications (CS) and Special Conditions (SC) issued by EASA for various A/C and product classes. This process is based on a certification programme that describes how compliance to every requirement from the certification base is shown.

Design Organizations (DO) work together with EASA to ensure safety of the design. Especially, Part 21 demands that every DO has Certification Verification Engineers (CVE) who independently of the design team check if a design is compliant to the applicable requirements from EASA. For software, product security and Airborne Electronic Hardware (AEH), dedicated sub-processes in the certification are undertaken to show that the design is safe and secure.

TSSC can support your new DO by defining procedures for the Design Organisation Handbook (DOH) for Software, security and AEH procedures.

TSSC has experience in defining certification programmes based on the specific CS and SC (e.g., SC E-18 and E-19 for electric propulsion systems) and can support with advice and guidance. We can also supply a CVE for SW and security for your design organisation that does the independent checking and presents the SW and security process results to EASA.

UAS / Drones

The certification of UAS for civil applications follows different approaches than that of manned A/C. EU regulations 2019/945 and 2019/947 lay down the rules for UAS in general. Depending on the class of drones (open, specific or certified), different rules apply to obtain an operational approval.

For the certified class, a Type Certificate, as for manned A/C is required to be obtained from EASA. For the specific class, the national authority and EASA work together for the approval. The SORA rules are used to obtain assurance that the UAS operation is safe (Article 11 of 2019/947). Here, the air and ground risk and the dedicated intended operation flow into the definition of a Specific Assurance and Integrity Level (SAIL) that induces involvement of EASA and what needs to be done for Software and AEH.

TSSC can support with the Software and AEH processes for UAS, also taking into account alternatives to DO-178C and DO-254 for the development, e.g., the new Lower Risk Development Assurance Standard under definition by EUROCAE WG-127 or the ASTM standard F3201.

For UAS in the certified category, TSSC can support with the overall Type Certificate process at EASA, as for civil manned A/C.

Military/Governmental Aviation

In governmental and military aviation, the rules for civil A/C do not apply, but approval is under national jurisdiction. Instead of a "certification", military A/C and drones are rather "qualified" by the military authorities, as the pure function is emphasized rather than the pure "safe for all" approach in the civil world.

Nonetheless, the EU has started to also harmonise military qualification processes in the context of the European Defence Agency (EDA), and has issued documents mirroring Part 21 and other EASA regulations. DO-178C and DO-254 are now widely used for the development of software and AEH for military A/C as well.

TSSC has experience in military Software and AEH development projects and can support with the definition of processes, also considering the stringent security requirements for the development itself, e.g., segregated development infrastructure from other company projects.

Training

For training information see Training