Abstract: A method and apparatus for undertaking remote non-destructive in-situ testing an elevated wind turbine blade includes the steps of providing a remotely controlled drone aircraft, applying a water soluble penetrant from the drone aircraft to a test surface area of the turbine blade, and then waiting for the water soluble penetrant to dry. Next, a dry powder developer is applied from the drone aircraft to the test surface area, and then awaiting for the dry powder developer to substantially set. The test surface area is then illuminated with an ultraviolet light source from the drone aircraft. Lastly, the test surface area is digitally photographed to effect an inspection for visible latent defects. Additionally, a solvent can be applied from the drone aircraft to rinse the test surface area of the wind turbine blade after waiting for the water soluble penetrant to dry and prior to applying the dry powder developer.