Kármán Line – generally accepted as the “beginning of space”
Traditional Aviation Operations
Higher Airspace Operations
Space
Why do most aircraft stop at around FL550 (55,000 feet)? According to the European Union Aviation Safety Agency (EASA), the ceiling is largely driven by engineering constraints: reduced air density limits engine performance and lift, cabin pressurisation becomes more challenging, and conventional ground-based navigation systems are not certified for extreme altitudes. Although some aircraft—such as the retired Concorde—have flown higher, routine commercial operations rarely exceed these levels.
However, above traditional cruising altitudes and below outer space lies what EASA defines as “higher airspace” — a largely unregulated zone with emerging commercial and scientific potential.
Emerging uses
Future higher airspace users could include:
- High-Altitude Platform Systems (HAPS) or “pseudo-satellites”
- Stratospheric balloons
- Supersonic and hypersonic passenger aircraft
- Near-space tourism capsules
These platforms could enhance telecommunications, navigation services, scientific research, ultra-fast passenger travel and even tourism. Development in this domain may also generate spillover benefits for conventional aviation, including environmental innovation and new employment opportunities.
Regulatory roadmap
In 2023, EASA published a Proposal for a Roadmap on Higher Airspace Operations, outlining technical, safety and regulatory challenges. The agency is now advancing work to:
- Increase EU institutional and public understanding of higher airspace
- Produce scientific data to guide policy decisions
- Conduct regulatory impact and gap analyses
- Develop a formal regulatory framework for EU airspace by end-2027
Ongoing studies cover safety, sustainability, cybersecurity, and human health considerations. EASA also plans to issue a Notice of Proposed Amendment as part of the rulemaking process.
International coordination
Because higher airspace operations are a global issue, EASA is coordinating with national aviation authorities and with the International Civil Aviation Organization (ICAO) to ensure harmonised standards and maintain a “safety continuum” as new vehicle types and operational models emerge.
While widespread higher airspace activity may still be years away, prototypes and demonstration flights are already underway globally. EASA’s preparatory work aims to ensure that innovation beyond traditional flight levels develops within a robust, proportionate safety framework.