Quadrotor Unmanned Aerial Vehicles (UAVs) are highly nonlinear and underactuated in nature as they possess fewer control inputs than control variables. A combination multiple UAVs conveying a single load is more complex but offers some advantages due to it’s complimentary nature. as such. heavier loads can be conveyed compared to using single UAVs. https://www.diegojavierfares.com/quick-find-Umpqua-U203-U-Series-Hook-clearance/