This technique was often used to transport poles, panels, beams, tubes, pre-manufactured elements, furniture, etc.
At the beginning pilots preferred to use this system instead of suspending the cargo on the barycentric hook, and this despite the fact that sometimes several minutes were necessary to adequately prepare each load and to correctly fix it to the undercarriage. In this way the pilot could, for example, take-off and take advantage of the ground-effect. However with sudden gusty winds the pilot could be seriously in trouble. This is why these kind of flights were only done with ideal weather conditions.
Another problem could arise in case of autorotation because the pilot could obviously not drop the cargo.
Moreover without external help he could not exit the cabin, a very dangerous situation in the case of post crash fire. Fortunately this kind of accident didn't aver occurred.
Picture n° 1, taken in Fiesch/VS in Autumn 1957, shows the Bell 47G2 HB-XAT ready for the transortation of some walls of a pre-manufactured mountain hut.
Picture n° 2
Picture 3 shows Hermann Geiger at the controls of the Bell 47J Ranger HB-XAU while transporting floorboards for the Mischabelhütte/VS.