More flights with lower environmental cost
An EU-funded initiative was launched to address rising concerns about airport capacity and environmental impact. The ‘Optimized procedures and techniques for improvement of approach and landing’ (Optimal) project sought to develop and validate innovative procedures and technologies related to aircraft and rotorcraft approach and landing. These methods were aimed at increasing the possible number of planes landing per hour, decreasing the noise and carbon footprint produced by airports and improving overall air traffic management (ATM). The researchers proposed using a displaced or dual threshold (DT) for landing on the runway as a means of increasing airport capacity. The geometry of the second threshold decreases air turbulence formed behind the aircraft as it lands and thus enables more planes to land in a shorter time interval. Validation studies demonstrated a significant increase in arrivals with the DT, with even better results during heavy traffic times. The researchers evaluated continuous descent arrival (CDA) and better integration of rotorcraft into airport procedures as ways of minimising noise and carbon emissions. Specifically, validation of modifications to conventional CDA, long acknowledged by the international community as providing reduced noise and gas emissions, demonstrated flyability and improved arrival time accuracy. The researchers proposed specific procedures for integrating rotorcraft into airport function, given that rotorcraft decrease noise, increase airport capacity and enhance safety due to vertical guidance. Finally, the researchers demonstrated operational benefits with three technologies developed for the Optimal programme. First, they designed and validated modifications to the global navigation satellite system (GNSS) using ground-, satellite- or aircraft-based augmentations. Second, they demonstrated the feasibility of using the enhanced vision system (EVS) developed by the Optimal programme for pilots landing in low-visibility conditions. Finally, they made recommendations for improvements based on the area navigation (RNAV) concept, employing station-referenced or self-contained navigation aids, or a combination of the two. Optimal project efforts produced innovative and validated procedures and techniques for improving approach and landing at airports. These demonstrate the ability to increase airport capacity, decrease environmental impact and ensure or enhance operating performance. The results should have significant impact on future European ATM systems.