Maximum of 5 passengers, in some situation if the group is above 5 to 10 pax, needs to shuttle the passengers. The Helicopter makes a round trip ferrying the passengers from near base camp to Syangboche and Lukla and back.This is why on this type of high altitude flight there is only one pilot to fly the Helicopter to make rooms for more passengers. As well to make the Helicopter engine lighter which is important on high areas of Himalayas.