Andrzej Jeziorski/FRANKFURT

GERMAN AIR-TRAFFIC-services agency Deutsche Flugsicherung (DFS) and Frankfurt Airport are to test a new wake-vortex warning system (WVWS) as part of a drive to increase the airport's capacity.

The WVWS, developed by Munich-based IABG, consists of a series of ten to 12 masts fitted with laser anemometers, mounted across the foot of the parallel runways at Frankfurt. Tests are due to begin, by the middle of this month.

These sensors will give controllers a precise picture of wake-vortex activity at the runway threshold, and of how the vortices are being moved by wind conditions. With the WVWS, combined with other new monitoring and planning systems, controllers may be able to reduce the separation of incoming aircraft (for a heavy aircraft followed by a light aircraft) from up to a standard 4km (2.5nm) for all weight categories. "We now have a capacity of 72 movements per hour on the parallel runways. We are trying to increase this to 80 movements," says the DFS.

The WVWS is to be combined with a precision runway monitor (PRM) by 1998. The PRM is a radar with a high update rate - more than 60 updates a minute - which monitors the final approach on the parallel runways, and allows controllers to reduce the separation of incoming aircraft.

Frankfurt is to introduce a four-dimensional planning system which will use ground radar and aircraft data, combined with information on airspace and noise restrictions, to plan a conflict-free flight path in four dimensions (space and time) for incoming aircraft. The system then makes guidance recommendations to the controller.

Source: Flight International