The paper addresses two highly interesting and important topics -loads and O&M of Multirotor systems.Therefore it is seen as highly relevant.The paper appears to be two papers, one on cost modelling (chapter 2) and one on loads (chapter 3), whilst the conclusions seem to address only loads and not costs.Although it is stated, that the whole paper has been written by the main author, it reads as two papers from different writers.Chapter two on costs reads more like a business report with many assumptions on input p…