In 2012, the European Commission carried out an investigation into the airports, (Endless Runway project lasted 2 years, Spain participated in the project through the National Institute of Aerospace Studies along with Germany, France and Poland and the commission of investigation concluded Which was viable with significant energy savings (wind) and noise impact.
There were many drawbacks. The cost was much higher, it would require about 10,000 m of track, a minimum width of 90 meters. The track would have a slope towards the center causing centrifugal forces, and the aircraft would slow down automatically in a trend towards the center of the track, and everyone, pilots and passengers would feel the sensation of going a roller coaster, and then At the end comes the question of the million, is it safe to land when three planes do at the same time?
I do not know…. I do not like it very much.
http://cordis.europa.eu/project/rcn/103897_en.html
