‘No survivors’ in Nepal plane crash, official says; recovered black boxes
“Because of its terrain, because of its weather, because it is necessary to fly between places – many of these communities are not connected by roads – it will always be a difficult environment with a higher level of risk. than other parts of the world,” aviation safety consultant Adrian Young told The Washington Post.
Here are some reasons why Nepal is so difficult for pilots.
Nepal is home to eight of the highest peaks in the world, including Mount Everest.
“It’s a most challenging operating environment,” aviation safety consultant Ron Bartsch told the Post. Three factors related to Nepal’s mountainous terrain make flying difficult: high altitude airports, short runways and strong winds.
In a 2019 report, the Civil Aviation Authority of Nepal cited the country’s “hostile” topography as one of the top two aviation safety challenges. The other is the weather.
Analysts say the weather and mountains could explain why so many air accidents in Nepal are classified as controlled flights into terrain, or CFIT, when a pilot crashes without appearing to have lost control.
Nearly 3 out of 4 fatalities in plane crashes recorded in Nepal over the previous decade were classified by authorities as CFIT, the Civil Aviation Authority reported. The majority occurred in mountainous regions.
According to a database maintained by the Airline Safety Network, two of the deadliest crashes in Nepal were CFITs. In 1992, a Pakistani airliner crashed into a rugged hillside in the Himalayas while trying to land at a Kathmandu airport in torrential rain, killing all 167 people on board. Two months earlier, a Thai Airways flight had also crashed in heavy rain, killing 113 people, including 11 Americans.
Many of Nepal’s airport runways are nestled among high peaks, which can be especially dangerous in low-visibility conditions.
According to the Civil Aviation Authority, the airport historically linked with the highest number of fatal accidents since 1960 is Tenzing-Hillary Airport at Lukla in the northeast of the country, located at 9,334 feet. The mountainside facility, built under the supervision of Sir Edmund Hillary, is famous for being the gateway to Mount Everest Base Camp. It is only accessible by helicopters and small planes with short takeoffs and landings.
Climbing Everest: an interactive experience
Landing a plane in a mountainous airport means pilots are more dependent on what they can see, said Young.
“If your airport is in a valley, at some point you will have to descend lower than the hills around them,” he said. In low visibility conditions, pilots tend to rely on on-board equipment or airport assistance to help them land the plane, which Young says not all Nepalese airports are equipped to provide.
The high altitude of Nepal poses another challenge to pilots: the drop in atmospheric pressure. According to World Atlas, the country’s average elevation is 10,715 feet.
“The higher you fly, the thinner the air,” Young said. “If you land at high altitude, there are flight performance issues.
“Some of the airports in Nepal are what we call ‘hot and high’, so you would expect rather warm temperatures and high altitude. This means there is less air for the wing to work with.
Young said aviation always involves risk; Nepal adds “special” risks. Still, he said, the air “remains a very safe way to travel”.