9-Day vs 12-Day Everest Base Camp Helicopter Trek: Which Fast-Track Everest Trek Is Best for You? www.treklanders.com 9-Day vs 12-Day Everest Base Camp Helicopter Trek | Best Everest Heli Trek Comparison Compare the 9-Day and 12-Day Everest Base Camp Helicopter Trek in Nepal. Discover itinerary differences, acclimatization, altitude risks, helicopter return, fitness level, costs, and which Everest trek suits your schedule best.