A two-year demonstration project called Augmented Approaches to Land has shown that curved satellite-based augmented navigation and augmented vision can improve airport access while reducing the impact of airspace users on the environment. This ambitious SESAR Large Scale Demonstration project conducted over 360 trial flights in real-life environments to validate new technologies and operations that have proven to be feasible and accurate, and that can provide benefits to the aviation community and the population.
In 2015 and 2016, fifteen partners from across the aviation sector worked closely together to deliver one of the most ambitious large-scale demonstrations in Europe. The Augmented Approaches to Land (AAL) project aimed to show the benefits and complementarities of several approach solutions for aircraft into different airport environments. It demonstrated that satellite-based navigation and augmented vision can improve airport access and reduce the impact of airspace users on the environment.
Co-funded by the SESAR Joint Undertaking, the project was led by NetJets Europe, supported by Honeywell and Dassault Aviation each leading technical work packages, and grouped major aviation stakeholders, including 4 airspace users, 4 avionics and aircraft manufacturers, 4 air navigation service providers, 2 major airports and 1 research organisation. Together they conducted more than 360 trial flights. More than half of which were performed by Lufthansa and SWISS on revenue flights using various aircraft types (Airbus A320 family, Airbus A380 and Boeing 747-800), and the remaining trial flights were performed by Honeywell Aerospace and Dassault Aviation flight test aircraft (Falcon 900 and Falcon 7X respectively).
Reduced impact on environment
The flexibility of satellite-based navigation connected to precision landing systems enabled the German and Swiss air navigation service providers (DFS Deutsche Flugsicherung and skyguide), in collaboration with Fraport and Zurich Airport, to implement flight procedures in Frankfurt, Zurich and Bremen that were tailored to needs of the specific airports and their local communities. Supported by the German Aerospace Center (DLR), they designed flight procedures using curved navigation tracks enabling shorter arrival procedures, while avoiding populated areas. Before performing trial flights in real life the procedures were tested in full flight simulation environments, benefiting from Airbus facilities and NAVBLUE navigation expertise.
The combination of these environmentally-friendly procedures and precision landing systems enables operators to use them in all weather conditions. Using certified Honeywell ground stations, the AAL project was the first project to widely demonstrate in a real-life environment the transition from curved satellite-based navigation to Ground Based Augmentation System (GBAS) precision landing capability. GBAS technology is foreseen as the capability that will enhance the capacity of major airports in low-visibility conditions, reducing current aircraft separation in those conditions, and maintaining the zero-visibility automatic landing function required for larger aircraft.
Some flight procedures were designed with an increased glideslope of 3.2-degrees, steeper than the standard 3-degrees glideslope, providing additional noise attenuation for the population. Honeywell Aerospace tested a new function enabling a seamless transition between the initial curved navigation and the precision-landing final approach. This new function maximises the noise benefit by supporting optimum continuous-descent operation during the initial and final approach phases of the flight.
Improved European airport network capacity
Environmentally-friendly procedures are also welcomed in small and regional airports. The AAL project confirmed that curved satellite-based navigation can similarly be connected to the Satellite Based Augmentation System (SBAS) precision landing capability. SBAS technology is particularly interesting for smaller airports as it requires no additional ground infrastructure, while enabling precision landing performance with decision heights as low as 200 feet. To further benefit from these procedures at small and regional airports, the project demonstrated on-board augmented vision capabilities enabling a significant gain in operational benefits. More than 70 trial flights were performed by Honeywell’s Falcon 900 flight test aircraft at regional airports in Brno, Ostrava and Karlovy Vary to evaluate Honeywell’s Synthetic Vision Guidance System (SVGS) SmartView; and 9 trial flights were performed by Dassault Aviation Falcon 7X flight test aircraft to evaluate its FalconEye, a Combined Vision System (CVS) developed in partnership with Elbit Systems. Also, more than 60 runs performed in full flight simulator by Dassault, Airbus and Flying Group pilots demonstrated the robustness of CVS operation in normal and abnormal conditions.
The Czech and French air navigation service providers (ANS CR and DSNA) supported these demonstrations. These advanced on-board technologies demonstrated the capability to lower the aircraft landing decision height by 50 feet, and reduce the required runway visual range down to 300 meters. Such aircraft performance can be leveraged by small airports through developing low visibility procedures, and the AAL project was the first initiative worldwide to analyse and describe, for small and regional airports, the minimum requirements to enable such procedures. These new airport requirements were successfully tested in a real life environment at Bordeaux, Bergerac and Perigueux airports.
It showed that with minimum adaptation, small and regional airports can accommodate aircraft with augmented vision capabilities that significantly improves their accessibility in low visibility conditions. While the only airports accessible in such conditions today are large, saturated airports, in the near future, with SVGS and CVS, business aviation will be able to continue using small and regional airports in all weather conditions, relieving the pressure on major airports, thus contributing to the on-time arrival of all air travelers.
Outlook
Tomorrow, a mix of legacy and advanced procedures will already enable more environmentally-friendly operations in Frankfurt. Moreover, curved satellite-based navigation connected to precision landing systems will enable environmentally-friendly procedures everywhere and in all conditions. Following these procedures, a commercial airliner will be able to conduct a zero visibility automatic landing at a hub using GBAS technology, while the pilot can be supported by augmented vision for better situational awareness. A business jet aircraft will also be able to fly a stable and efficient precision approach at most small and regional airports thanks to SBAS technology, and land in all weather conditions supported by augmented vision. What is really interesting is what these technologies can do together.