This video shows three experiments with the the new OTHex platform developed by us at LAAS-CNRS. The OTHex is a multi-directional thrust hexarotor with a simple arm that is able to assist in lifting and transporting long bars.
Details on the method are given in this paper 
- , “Towards a Flying Assistant Paradigm: the OTHex”, in 2018 IEEE Int. Conf. on Robotics and Automation, Brisbane, Australia, 2018, pp. 6997-7002.