Wind turbines have a design life of 20 years. The rotor blades must be regularly inspected at least once every four years to verify their structural integrity. This type of work is performed by industrial climbers. But the problem with inspecting offshore installations is that access is only possible when wind and weather conditions permit. This makes it very difficult to plan inspection visits. In the Thermoflight research project, scientists are working together with industrial and research partners to investigate alternative inspection methods. The use of offshore drones equipped with thermal imaging cameras in combination with acoustic monitoring systems could potentially improve maintenance efficiency and help reduce downtime.