Why Do They Call It A Dangerous Airport

The vast majority of airports are safe throughout the world. However, some airports are considered dangerous for several reasons, including (a) elevation, (b) terrain surrounding the airport, (c) weather. Each of the factors can add risk to taking off, approach, landing, and conducting go-arounds. This article is going to answer the question;

What makes an airport dangerous?

High elevation poses a severe risk for aircraft that are taking off and landing due to a reduction in air resistance. According to Nikel (2019), the reason that high elevation poses a risk to aircraft is due to a reduction in the controllability of the aircraft caused by a reduction in air resistance. At sea level, there is more excellent air resistance than at 30 thousand feet because as the elevation increases, air resistance decreases. Nikel (2019) claims that at high elevation, there is a reduction in the power generated by the aircraft engines, and a reduction if lift by the aircraft wings. Furthermore, at high elevation, it takes longer for an aircraft to stop due to the lower air resistance (Nikel, 2019). Tenzing-Hillary Airport in Lukla Nepal at 9325 feet above sea level (Nikel, 2019) and Courchevel Altiport in the French Alps at 21,325 feet above sea level are examples where high elevation affects aircraft performance.
While high elevation poses a risk for aircraft, the terrain surrounding the airport can equally serious risk for aircraft. The terrain surrounding an airport can (a) put physical constrains on an aircraft approach to land, (b) create challenging takeoff and landing conditions, (c) cause the airport to have no ago around approach. The primary way the terrain puts physical constrains on an aircraft approach to land is by affecting the descent into the airport. McFadden (2020) shows that the approach to Tancontin Airport in Honduras requires pilots to make a steep bank and rapid descent to land because of the mountain surrounding the airport. Dewsbury (2011) highlights how the terrain put physical constrains on an aircraft approach to land when describing the approach into Paro Airport in Bhutan. Dewsbury states that that approach to Paro Airport requires aircraft “to weave through dozens of houses that are scattered across the mountain side-coming within feet of clipping roofs” (p.X), along with making a steep descent into the airport to land. McFadden (2020) adds that pilots do not see the runway until the last second before touchdown due to the sharp bank angles and the rapid descent into the Airport.
The terrain can also be challenging for pilots taking off and landing. The terrain surrounding the airport can be narrow, have a mountain at the end of the runway or a sheer cliff at either end of the runway. For example, St. Maarteen Airport in the Netherlands Antilles has a mountain at the end of the runway that pilots must navigate departing the airport, whereas Courchevel Altiport pilots must navigate through a narrow valley upon take-off (Patil, 2018). In Colorado at Telluride Regional Airport, there sheer cliffs at either end of the runway (McFadden, 2020), which poses a risk on landing due to the high elevation of the airport requires a longer runway for an aircraft to come to a stop. The examples show that the terrain can pose a risk to aircraft in many ways; such was the case with a physical obstacle in Infront of the runway or cliffs at either end of the runway.
The terrain at some airports prevents aircraft from going around on a missed landing. Tenzing-Hillary Airport is one airport where there is not go around approach for missed landings. Nikel (2019) points out at Tenzing-Hillary Airport, the terrain around the airport prevents pilots from going around on a miss approached, thereby requiring pilots to stick the landing on the first attempt. Also, at Courchevel Altiport, go-arounds are not possible the mountain terrain around the airport ( Lo, 2019). Not having a go around approach can have disastrous consequences, including fatal crashes.

Weather poses a severe risk such as aircraft getting touch in downdrafts from thunderstorms have shown to cause aircraft to crash. The weather can be unpredictable and more so in mountainous terrain. Nikel (2019) and Magar (2020) claim that the weather in the Himalayas is extremely unpredictable, with wind shear causing both head and tails winds, along with preventing flights to land at airports such as Tenzing-Hillary Airport. At the same time, the weather can produce conditions where visibility is reduced, making landing impossible. McFadden (2020) states at Svalbard AirPort, “[inclement] weather and proximity to the Earth’s magnetic north pole can create visibility and navigational difficulties for even the best pilots” (p. X). The reduced visibility and difficulties navigating increase the risk at the most critical part of the flight. 

Conclusion

No airport is inherently dangerous but can be affected by elevation, terrain, and weather patterns. Elevation can affect an aircraft in several ways, including a reduction (a) power generated by the engines, (b) lift generated by the wings, along with increasing the total distance required to bring the aircraft to a safe stop. The terrain surrounding the airport can put physical constrains on approach, landing, and takeoff, such as requiring high angled turns with rapid descent on approach to the airport. At the same time, pilots might have to navigate through terrain on take off such as mountains and narrow valleys that can be found at some of the remote airports. While elevation and terrain a pilot can prepare for, the weather can change fast. Unpredictable weather patterns can scientifically reduce visibility, cause wind shear, which all can make a challenging approach more difficult. At the same time, pilots are trained to handle all the conditions and take every precaution to ensure the safety of the passengers. 

Until next time, and as always, “We Speak Aviation.”

The article is written by Pilotamireh Social Media Team Member Dr. Robert Lino