 Disadvantages include the loud noise causing difficulties in communicating with the survivors and the strong downdraft that the hovering helicopter creates which increases wind chill danger for already-soaked and hypothermic patients.Helicopters also tend to have limited range and endurance.Toward the end of World War II, several B-29 bombers on each large-scale bombing mission were emptied of ammunition, filled with rescue supplies and rotated through Super Dumbo patrol duty as their squadron mates lumbered off filled with bombs.