KATHMANDU, April 28 (Reuters) - A record number of mountaineers expected on Mount Everest during the current spring climbing season has sparked fears of a traffic jam when teams make their final ascent through the "death zone" to the summit of the world’s tallest peak. "This can lead to climbers running out of oxygen and facing exhaustion/exposure in the ‘death zone’," he added, referring to altitude above 8,000 metres (26,246 feet) where the air is too thin to survive for long without supplementary oxygen. Lukas Furtenbach of Austria-based Furtenbach Adventures said the higher number of climbers was not a problem so long as they are managed well and the weather holds long enough to have more days to spread out teams' attempts on the summit