The Endless Runway, a practical solution for airport expansion
The Endless Runway is a radical idea for a concept of a runway that effects the improves operations and construction of the whole airport.
The Netherlands Aerospace Centre (NLR) has been exploring these issues for decades, with a focus on the long term and led a consortium of research centres that investigated the idea of a circular runway.
This circle, like a large wheel, has no limitations on where to take-off or land on this circle. This makes it possible to fly in from any direction.
The size of the circle is pretty large, its diameter is 3.5 kilometres. This means that passengers during take-off or landing will not feel like they are in a roller coaster, a typical landing only requires a part of the runway with a limited curve.
Current airports operate runways with fixed directions, so a limited number of directions are available for take-off and landing. During a storm, the capacity of the runway is limited due to dangerous crosswinds. Fixed runways also mean communities down-wind experience more noise than others.
With the Endless Runway, aircraft have the possibility to land anywhere on the circle. This results in pilots always having the option of one point where there is no crosswind and only headwind, which means that no capacity is lost in unfavourable wind conditions.
The runway capacity is at least similar to that of a conventional airport with four runways, while the length of the circular runway is comparable to three. This makes it possible to use the runway with several aircraft simultaneously.
Flight times in the area around the airport will be reduced as aircraft can now almost fly straight in and out. It will also be possible to avoid large communities with routes designed to avoid areas where most people live, or design routes such that everyone around the airfield will experience a similar level of noise.
An advantage of the concept is that the airport buildings can be constructed in the middle of the circle. It is estimated that a large airfield like Charles de Gaul in Paris would fit within the circle, which occupies an area of about one third of the size of the current airport.
One thing about safety. The border of the runway would be banked so that aircraft would not easily fail to make the bend. The aircraft will take-off making the circle and land while already making the first turn of the circle.
Live trials have been performed in the past century on a smaller circle at a military airfield in the U.S, where pilots reported the landing in a turn was possible and after some trials not even very difficult.
The aviation sector currently doubles in size every 15 years, so might this circular runway be an idea that will facilitate that growth while at the same time improving safety and security and reducing environmental impact while allowing airport capacity to expand without detrimental effects on the liveability of the human environment?