EUROCONTROL has reported a joint effort with the ANSP for France, direction des Services de la navigation aérienne (DSNA) and Toulouse-Blagnac Airport to validate safety aspects associated with using drones to inspect the airport grounds with one runway remaining active.
They developed a generic safety case using drones to inspect runways, taxiways and approach lighting and to calibrate PAPI, the precision approach path indicator for pilots. The tests were successful as a first step toward future safe integration of drones into airport operations, which has the potential to enable important efficiency improvements.
One of the major safety challenges was to maintain air operations with take-offs and landings on one of the runways, while inspecting the adjacent runway located less than 300 metres away. All risks needed to be carefully evaluated, including potential mid-air collisions with aircraft landing or taking off from the adjacent active runway, but also collision risks on the ground (people, vehicles and sensitive equipment).
The preparation for the live experiments also included defining 3-dimensional volumes of airspace that the drone should not leave for each type of inspection, the development of a specific drone phraseology and radio communication procedures; for this they worked with an experienced drone pilot. In addition, the study took into account all the possible risks that might affect the navigation or the stability of the drone, such as adverse weather conditions (wind, precipitation) or technical failures related to the drone or the communication system (C2 link).
When it came to operating the drone, the challenge was flying it in BVLOS (beyond-visual-line-of-sight) mode, in particular for the runway inspection, when the distance from the drone pilot was greater than 1 km. This meant that the drone was flying beyond the pilot’s visual sight, the only link between pilot and drone provided by an on-board camera and the geolocalisation function of the drone. This is where the “geo-caging” function came into play, alerting the drone pilot if the drone were to approach the boundaries of the predefined volume of airspace in which it operated.
The are many possibilities for extending drone use in and around airports. They could be used for numerous applications such as ILS calibration, wildlife management, and inspections of airport buildings, fences and aircraft airframes on the aprons.