Kathmandu, June 4 -- year-old guide Lakpa Ringi Sherpa, this spring climbing season on Everest felt different.

The fear was still there. The Khumbu Icefall remained as unpredictable as ever, with yawning crevasses beneath his feet and towering seracs looming overhead. But unlike previous years, he did not have to make the dangerous journey through the icefall carrying heavy loads over and over again.

Instead of the usual eight to ten supply trips between Everest Base Camp (5,364m) and Camp II (6,400m), Lakpa Ringi made only four.

The reason was not a safer route or calmer weather. It was a drone.

"Every year, we are frightened to cross the icefall," he said. "Crevasses below, seracs above. We have to walk between unstable ice formatio...