He is short, wiry and shies away from the glare of publicity. And yet this 49-year-old has placed his feet on top of the world's highest mountain more times than anyone else.
Now, Appa, a professional sherpa from a small Nepalese village who has reached the summit of Everest on 18 occasions, is heading back to the mountain to break his own record. In doing so, he hopes to draw attention to the plight of the mountain, increasingly threatened by litter and debris and the effects of global warming.
"I am not looking for recognition or doing this just to beat my own record. My objective is to highlight the environmental degradation of the mountain and draw attention to the issue of global warming," he said yesterday, as he and his 40-strong expedition team set off from Kathmandu. "For us sherpas, Everest is not just the mountain. Everest is our god. I want to see Everest clean and safe."
Appa grew up in Thame, the same Himalayan village as Sherpa Tenzing, the man who in 1953 made the first successful climb to the summit of Everest alongside Sir Edmund Hilary. The village is home to many other sherpas but as a child he might have been destined for a different future had it not been for the death of father.
Appa was just 12 when his father, a yak herder, died, and it reportedly fell to the young boy to look after his mother and siblings, two sisters and three younger brothers. (One of them, Ang Rita, would later make history by standing with Appa on the top of Everest, the first brothers to conquer the mountain.)
Burdened with such a responsibility, he was forced to abandon his studies and earn money by carrying loads for trekking groups in the region. A scholarship provided by a foreign tourist gave him an opportunity to start studying again but it was not long before he began to feel the pressure of poverty and he returned to the mountains. In 1985 he was hired to work as a kitchen assistant for the Swiss climber Erhard Loretan's attempt on Annapurna. It was his first proper expedition and it would provide him with his vital break.
Two years later he was hired by a Japanese expedition attempting the same mountain and then the following year, 1988, he joined two expeditions that were making bids on Everest. His lack of experience, linked to a limited knowledge of the route, meant that he did not make it above 27, 900ft on the 29,029ft mountain. That same year Appa married a young woman from his village, Yang Chi, and they soon had their first little boy, later to be followed by another son and a daughter. In 1990, Appa would scale Everest for the first time after joining an expedition lead by the New Zealand climber Rob Hall, a veteran mountaineer who would perish in a 1996 attempt.
Sherpas are the backbone of any expedition in the Himalayas. They lay out miles of fixed ropes for the non-sherpa climbers to attach themselves as they make their ascents, they help carry gear and they are often called upon to rescue stranded climbers, some of whom push themselves beyond their abilities.
While Western climbers who die in the Himalayas usually receive big headlines, the many sherpas who perish are seldom more than footnotes. Sometimes they are not insured, leaving their families to struggle.
During his early days as a hired member of various expeditions, Appa did not disguise the fact that he saw climbing as a decent-paying job in a part of the world with few alternatives for employment. In an interview with the United Sherpa Association of the US, he once said: "For me the most important thing is my wife and children and the proper education of my children. One way of making someone you like happy is to make money and climbing Everest is the most [the ideal] profession for me."
Yet the expedition that he hopes will take him to the top of Everest for the 19th time – his nearest rival, Chhewang Nima, has reached the summit a mere 15 occasions – is inspired by a different concern; the increasing environmental threats to a mountain the sherpas consider sacred. Litter and rubbish discarded by the dozens of commercial expeditions that attempt to climb the mountain every year, have turned parts of Everest into a high-altitude dump. Left-over climbing equipment, litter, and human excrement that fails to decay have transformed this once-pristine Himalayan landscape.
He said that he and his team members would be carrying hundreds of bags that can be used to carry excrement and other rubbish and transport it down the mountain so it can be disposed of properly.
"The beauty of Everest is deteriorating as climbers leave their garbage on the mountain... We must discourage such practices. The mountain is not just a god for us but the snow and ice is the source for water we drink," he told the Agence France-Presse. "Leaving behind human waste is not just insulting to the mountain god but also contaminates the source of water... Due to heavy commercialisation of Everest, the sacred spiritual aspect of the mountain is fading and this has become very worrying for the mountain people."
Yet Everest is facing other problems, ones that will be far harder for Appa and his climbing colleagues from the Eco Everest expedition to confront. Climate change has struck the mountain and climbers have already noticed the steady and ongoing break-up of the Khmubu icefall, a notoriously-dangerous maze of cliffs and crevasses on the southern side of the mountain and through which anyone climbing by via the south-east ridge routes must pass.
"The snows are melting on Everest. I cannot imagine Everest turning into a naked rock," added Appa. "Bad things are happening on Everest and to Everest not only because of global warming but also because we are treating our god badly. You never know when the weather turns bad there but the mountain needs care and the risk I am taking is worth it."
Appa has said that as a result of several high-profile fatalities on Everest, his wife is keen for him to put climbing behind him, and two years ago he moved to Salt Lake City in the US. He has said it would be up to his own sons to decide if they wish to become climbers.
Still, he is adamant that young Nepali should put their education first, something he was unable to do. "I want to advise the younger generation that education is the most important thing to change you and your community," he said. "I feel that the young sherpas should not take breaks to work as guides and climbers. I would say, fly your kite as high as possible, but do not break the string yourself."