Helicopters just don't work safely at that altitude. It also has persistent inclement weather conditions. I've spent some time in La Paz, and other areas in Bo

Helicopters just don't work safely at that altitude. It also has persistent inclement weather conditions. I've spent some time in La Paz, and other areas in Bolivia at high altitude. The effect in the human body is extreme. Sometimes you struggle to take ten steps up a slight gradual incline. It's insane. La Paz and Quito are two airports I found particularly daunting to land at. Both surrounded by mountains at high altitude.