A new method of improving both airways safety and the flow of aircraft in and out of airports is being mooted by Boeing. A long-standing constraint on traffic flows has been the requirement to allow sufficient distances between aircraft to allow wake vortices to dissipate. These invisible streams of turbulence flow off an aircraft's wingtips and can severely destabilise an aircraft following too closely. Several accidents over the years have been attributed to this phenomenon. Disperse Typically, a gap of three miles must be left between two aircraft of similar size to give the vortices a chance to disperse. Boeing has developed a technique that produces a counter-vortex to help break up the pattern of turbulent air, potentially allowing smaller separations between aircraft, according to a report in New Scientist magazine. Earlier wind-tunnel experiments by Boeing engineers had discovered that oscillating the inner and outer ailerons out of phase could produce a wave-like disturbance in the aircraft's slipstream that broke up the wingtip vortices. However, this produced too much stress in the wings to become a commonly-used technique. Now, engineers have discovered, combining small perturbations in the outer ailerons and wing spoilers can produce a new set of vortices, which interferes with the wingtip vortices, helping cancel each other out. The patented system includes an onboard sensor, which measures the strength of the vortices the aircraft leaves in its wake and communicates this information to the aircraft following behind, which can then make the necessary modifications to its own aileron and spoiler settings. The only potential problem arising from the system would seem to be the additional pressure that the additional traffic flows could place on already stretched air traffic control systems in certain parts of the world.
Source: Flight Daily News
