High Altitude Platform Stations are aircraft systems for stratospheric operations in an air density of about 7 % of the ground standard atmosphere. HAPS loiter at their station for multiple days. The unfriendly environment and the kind of operation ask for unmanned aircraft systems controlled by pilots in a Ground Control Station. This is quite novel with respect to airworthiness certification and operation in the civil airspace and a close look at the stakeholders, the regulatory bodies, and the regulations already in place is required. ICAO requires an integration of unmanned aircraft into the ‘total aviation system’, so the safety standards for manned and unmanned flight are literally the same. The National Aviation Authorities like EASA in Europe have established the joined working group JARUS to implement rulemaking and to create certification requirements for a safe integration of unmanned systems into the civil airspace on this baseline.
The International Civil Aviation Organization (ICAO) is a UN specialized agency, established by States in 1944 to manage the administration and governance of the Convention on International Civil Aviation (Chicago Convention). ICAO works with the Member States and industry groups to reach consensus on international civil aviation Standards and Recommended Practices (SARPs) and policies.
So far ICAO has published Circular 328-AN/190 and a draft Concept of Operation for Remotely Piloted Aircraft Systems (RPAS) and amended Annexes to the Chicago Convention to accommodate RPAS intended to be used by international civil aviation.
In 2012 Amendment 43 to Annex 2 to the Chicago Convention was adopted:
- the civil RPAS has to be airworthy (or at least safe enough for sustained flight), otherwise no flight operation can be initiated in line with Article 31 of the Chicago Convention
- the remote pilot shall be competent and, where required, licensed, in accordance with Article 32 of same Convention
- the civil RPAS operator (commercial or non-commercial) shall be certified (or hold other form of authorisation)in line with the modern approach to aviation safety (e.g. enshrined by ICAO Annex 19)
- only after (1), (2) and (3), the RPAS operator may request to access non-segregated airspace. In summary, the ICAO standards require that RPAS are inserted in the ‘total aviation system’ and not just ‘into the airspace’ (or Air Traffic Management (ATM))
JARUS (Joint Authorities for Rulemaking of Unmanned Systems) is a group of experts from the National Aviation Authorities (NAAs) and regional aviation safety organizations. Its purpose is to recommend a single set of technical, safety and operational requirements for the certification and safe integration of Unmanned Aircraft Systems (UAS) into airspace and at aerodromes. The objective of JARUS is to provide guidance material aiming to facilitate each authority to write their own requirements and to avoid duplicate efforts. At present 46 countries, as well as the European Aviation Safety Agency (EASA) and EUROCONTROL, are contributing to the development of JARUS.
EU Regulation 2019/947 on the rules and procedures for the operation of unmanned aircraft caters for most types of operation and their levels of risk. The Regulation allows operation of unmanned system in general and requires an equivalent level of safety compared to manned systems:
- Unmanned aircraft, irrespective of their mass, can operate within the same Single European Sky airspace, alongside manned aircraft, whether airplanes or helicopters.
- Considering the specific characteristics of UAS operations, they should be as safe as those in manned aviation.
- The risk level criteria as well as other criteria should be used to establish three categories of operations: the ‘open’, ‘specific’ and ‘certified’ categories.
A HAPS RPAS is an aircraft with a very specific concept of operations, not intended for general use like a standard airplane. With the definition of specific operational procedures and related specific aircraft systems it is possible to limit the certification complexity, leading to a Restricted Type Certificate, which limits the aircraft to the specified specific operations.
- ‘open’ (low risk) is a UA operation category that, considering the risks involved, does not require prior authorisation by the competent authority before the operation takes place.
- ‘specific’ (medium risk) is a UA operation category that, considering the risks involved, requires authorisation by the competent authority before the operations take place and takes into account the mitigation measures identified in an operational risk assessment, except for certain standard scenarios where a declaration by the operator is sufficient
- ‘certified’ (high risk) is a UA operation category that, considering the risks involved, requires the certification of the UAS, a licensed remote pilot and an operator approved by the competent authority, in order to ensure an appropriate level of safety.
In the German Federal Ministry for Transport and Digital Infrastructure (BMVI), the Aviation Directorate-General deals with national and international aviation, aviation policy matters, airports and safety in air transport. With the help of the Federal Aviation Office (LBA), the Federal Supervisory Authority for Air Navigation Services (BAF), the German Federal Bureau of Aircraft Accident Investigation (BFU) and the German Air Navigation Services (DFS), the directorate-general facilitates the smooth flow of air traffic in Germany, provides for the safe operation of German air carriers and takes into account all environment and noise- and consumer protection-related concerns. It also represents Germany’s interests on international bodies and organizations.