Airports could use a makeover, is this the solution?
That one challenge airports face is, managing the inbound and outbound flow of traffic efficiently. Air travel is vital to transportation. While the airlines are working aggressively on increasing their capacity and utilization, airports around the world, mainly the ones serving as hubs are feeling the pressure and runways- the ‘weight’.
Routing air traffic in and out of the airport terminals, meeting the demands of airlines and schedules without compromising on safety and time is a great skill, and yet knotty.
One person however, proposed an idea to renew the airport infrastructure and better its performance by smoothening this process.
The Concept of Circular Runways
The Netherlands Aerospace Center, committed to research and deliver sustainable solutions to the aviation industry reflected the dream and idea of Mr. Henk Hesselink who, after seeing the horrors of crosswind landings was motivated to come up with solutions to counter their effects.
The overview of this concept suggests that there shall be a banked circular runway with a diameter of 3.5 km surrounding the airport. At any given time, up to three aircrafts can use the runway to land and/or take-off. Aircraft can enter or exit at desired points on the runway acting as tangents to the circle. This flexibility would keep them away from the path of a crosswind and consequently, its dangers: the very problem, the idea was conceived to solve.
Mr. Henk Hesselink also believes that this concept will have a positive social and environmental impact as it would result in less fuel burnt, contradictory to other cases where aircrafts may circle the airport awaiting clearance for landing. Since the aircrafts have the liberty to fly in and out from any direction, we could be socially responsible by choosing flight paths that avoid populated areas hence reducing effects of noise.
The team is known to have used simulators to test the design’s feasibility. However, as impressive as it seems, there are many aspects that question its viability.
On a conventional runway, rudder inputs are made to align the aircraft to the center of the runway which is imperative during take-off and landing. In the case of a curved and banked runway, pilots must continually provide and maintain input to ensure stability of the aircraft from a runway center-line and bank angle perspective. This process no doubt becomes tedious, challenging and treacherous to deal with.
An object moving in a circle is subject to an outward force called the Centrifugal Force. The same principal is applied to this case and the researchers claim that it is this force that would aid in slowing the aircraft during landing. However, we cannot defy the laws of physics: the Centrifugal Force acting outward is bound to push the aircraft towards the ‘outer circle’ where the bank angle is higher causing further complications in handling.
Wing Span & Wing tip protection
Runways are used by aircrafts of different sizes, consequently aircrafts with varied wing spans. Majority of air-traffic today comprises of commercial airliners with large wing spans. In a banked runway, it is highly likely that the wing tips would come in contact with the runway resulting in either wingtip damage or catastrophic structural failure.
There have been numerous cases where incidents have occurred during a landing or take-off procedure declaring an emergency at the runway. We encounter these scenarios even to this day despite having sophisticated technologies, reliable ground control and skilled pilots in cockpits. These cases are simply unpredictable and only preparedness can help us get past it. This is one of the reasons why a runway’s length averages around 7000 ft, giving an aircraft enough room to recover from or handle critical situations.
With all that said, imagining emergencies on a circular runway is very alarming. We now know that at least three aircrafts would be on the runway at any given point. If one encounters an emergency, this could potentially endanger the safety of an aircraft directly behind it even though they maybe few hundreds of meters apart. Additionally, an emergency at any point on this type of runway could render the airport inoperative as it would call for a complete shutdown of the runway to account for safety. This is certainly damaging to the health of an airport.
The idea of circular runways comes with increased operational difficulties and compromises the safety in air travel. It brings along complications and can receive credibility only when seen and validated from a pilot or aviation expert’s perspective.
The concept is interesting and as an admirer of innovation and sustainability, I believe that the work of this Aerospace institute and Mr. Henk Hesselink is commendable. It is this disruptive thinking and determination to change the existing profile that leads the way towards advancement and positive social and environmental impact.