Objectives of the service
PAPI lights (Precision Approach Path Indicator) are an essential facility for aircrafts safe approach and landing at airports. These lights are configured, to provide pilots with an indication of the aircraft position on a predetermined glidepath towards the runway and the Touch-Down point. ”2 red and 2 white lights” indicate a correct Glidepath. 3 whites and the aircraft is too high, and 3 red lights indicate the aircraft is too low.
There are regulatory demands for maintenance and calibration of the PAPI light system. Today calibration is performed by twin-engine aircrafts, flying several approaches on all runways at an airport, to measure the accuracy of the PAPI lights system.
This method is time consuming and forcing airports to limit the operational capacity when calibration flights are performed. Combined with the negative environmental impact, this has also a very costly impact.
The S-DALP solution is based on the use of high-performance drone data to replace conventional PAPI light calibration, with a modern, safe and effective alternative. Using satellite navigation aids, the ambition is to fly the drone in a precise calibration pattern, obtaining the relevant data from the glideslope flightpath, to generate a report to calibrate the PAPI system.
Users and their needs
The primary user groups for drone-based calibration of PAPI lights are airports operators across the world. The initial target is in Denmark and Greenland. S-DALP creates value for airport stakeholders, airlines, flight training providers, civil aviation authorities (CAAs), maintenance personnel, and others.
All airports need to calibrate the PAPI light system accurately and efficiently to ensure safe aircraft landings. There are also many requirements and regulations associated with maintenance of PAPI systems, so documentation is essential.
Flexibility to perform inspections and calibrations both day and night enhance safety, efficiency and lower operational costs. The increasing demand to find new innovative methods to reduce carbon footprints in the Aviation industry, is also an identified need – and is a well-integrated requirement in the Airports business strategy.
Service/ system concept
The service is thought to be able to provide precise calibration of Precision Approach Path Indicator (PAPI) lights at airports using drones, with key data supplied by positioning satellites. This ensures accurate guidance for pilots during landing, enhancing safety and efficiency. The user can receive detailed calibration reports to replace old-fashion PAPI calibration methods conducted by airplanes.
The solution relies on the following main building blocks:
- The PAPI Light Units: these are four high-intensity lights installed beside the runway, showing red or white depending on the pilot’s vertical position relative to the glide path. This component is already existing and does not need to be modified, making the solution easy to deploy and scale.
- The Drone-Based Calibration System: the drone Operator obtains permission to operate in the Airport area thru the concerned CAA. This is achieved via the SORA (Specific Operating Risk Assessment) system, which is an integrate procedure within the EASA (EU) 2019/947 legislation. GNSS and RTK (Real Time Kinematic) are activated, along with a high-performance camera payload, so the drone can collect correct and precise data. Software has been developed, to process the data to generate a calibration report. Responsible maintenance crew at the Airport can then adjust the PAPI lights to the correct angle, and pilots can safely follow the lights all the way down to 200 feet above the runway.
Space Added Value
When using GNSS data and RTK technology provided from satellites, several benefits can be added to the solution.
- Very High Accuracy: Better positioning and enhanced safety in the airspace around an airport
- Cost Savings: Drones are cheaper to operate than calibration aircrafts and reduces the CO2 footprint significantly.
- Flexibility: Operation in various conditions and times.
- Less Downtime: Faster calibration reduces airport disruptions.
Current Status
The Kick Start activity has been completed, confirming the technical and commercial potential of using GNSS-enabled drones for PAPI inspection and calibration. Key partners and potential airport demonstration sites have been identified, while regulatory approval remains a key requirement for operational deployment.
Dialogue has been established with the Danish Civil Aviation and Railway Authority regarding the regulatory pathway. The activity has progressed through its planned review activities, and the final results conclude that no major technical barriers have been identified, with further demonstration and validation activities recommended before commercial deployment.
Prime Contractor(s)
Subcontractor(s)
