Reduced traffic queues at airports
When aeroplanes take off they disturb the air behind them. This means that the next plane taking off has to wait a specified time – the wake turbulence separation minima – until it is safe for it to take off. Recent research suggests that this standard time interval can be reduced under specific conditions while maintaining current levels of safety. The 'Crosswind-reduced separations for departure operations' (Credos) project aimed to validate this concept. Although limited in its initial scope to single-runway departures, the project’s concept is one possible solution towards improving airport capacity and reducing delays at airports. Previous work had suggested that, above a certain crosswind threshold, vortices are blown out of the flight corridor and pose no further threat to the aircraft that follow. As many European airports operate in crosswind conditions for a significant portion of time, there is a significant potential for reducing aircraft separations. The project studied the operational feasibility of this approach by focusing on the situation for take-offs under crosswind conditions. The work was performed by 11 European organisations working closely with the Federal Aviation Administration in the United States. Credos measured the air disturbances caused by aircraft taking off at American and European airports. The researchers used this data to develop models of wake vortex behaviour. By means of simulation techniques of aircraft departures, these models were used to establish safe separation times under various crosswind conditions. The project delivered an operational concept for reducing the time interval between crosswind departures being developed and validated. In the longer term, this may mean shorter waiting times for both aircraft and passengers at airports before they take off.
