More than 300 people have died attempting to reach the summit of Mount Everest, with countless more injured. Yet the dangers begin well before trekkers even reach base camp. The most common way hikers reach the area is to fly to the tiny Himalayan settlement of Lukla, 9,383 feet above sea level.
The alternatives all involve several days trekking, and so multiple flights carry hikers between Kathmandu and Lukla every day. Although the flight time is just 25-30 minutes, the two airports are as different as night and day.
Every possible danger at Lukla
Airports can be challenging to pilots for many reasons, as seen on this list of dangerous airports in Europe. Sometimes it’s the short runway as on many Greek islands. Places like Gibraltar suffer from regular wind shear, while mountainous terrain surrounding airports like Innsbruck creates obvious risks. Airports at high-altitude present dangers due to the effect that low air pressure has on the handling of an airplane.
Tenzin-Hillary Airport in Lukla, Nepal, has not just one but all of these dangers.
High in the Himalayas
While far from being the world’s highest civilian airport—that honor goes to Daocheng Yading Airport in China’s Sichuan province—Lukla’s altitude is still more than enough to cause pilots problems.
The airport is surrounded on all sides by steep, mountainous terrain. The short runway is perched on little more than a mountain shelf. At one end there’s a wall and at the other a steep drop into the valley below.
At these altitudes, air density is considerably lower than at sea level and that has a detrimental impact on the amount of power generated by the aircraft engines, reducing lift. Reduced air resistance also makes it more challenging to slow the plane down. At high altitudes, the longer the runway, the better.
Unfortunately for pilots landing at Lukla, the airport runway is extremely short at just 1,729 feet long. Runways at many of the world’s international airports are more than 10,000 feet long. So short is Lukla’s runway that it slopes uphill with a gradient of almost 12% to assist planes in slowing down in time.
To make matters worse, there is so little opportunity for a missed approach because of the surrounding mountains that there are no go-around procedures. Once an aircraft starts its approach, it must touch down. Given these factors, only helicopters and small fixed-wing propellor planes are permitted to land.
Poor weather means poor visibility
Weather in the Himalayas is highly unpredictable. Sudden mist, fog, rain storms or snow are always possible. Despite the short distance and short flight-time, the weather in Lukla can often be completely different from Kathmandu, and frequently changes while the airplane is on its way.
In such circumstances, planes turn around and return to Kathmandu. Afternoons are so frequently cloudy that most flights are scheduled for the early morning. Cancellations from Lukla are common.
Accidents at Lukla
Some airports considered challenging or even dangerous by pilots have an exemplary safety record. That’s not the case at Lukla, where there has been a list of incidents into double figures. Many of the more recent ones have even been caught on camera.
The most notable occurred in 2008 when Yeti Airlines Flight 103 crashed into the mountain a few feet below the start of the runway. The pilot lost visual contact in heavy fog during final approach but attempted a visual landing nevertheless. All 16 passengers and two of the three crew were killed. The pilot was the only survivor.
The Civil Aviation Authority of Nepal now sets high standards for pilots. To land at Lukla, pilots must have completed 100 short-takeoff-and-landing flights, have at least one year of such experience in Nepal and have successfully completed ten flights into Lukla with a certified instructor.
There is a technical study underway to assess the feasibility of a runway extension, although this would be limited to just 100 feet. Construction of a new helipad is also underway to increase passenger capacity.
