Map coverage to the physical blade

A series of overlapping views can look comprehensive while the back of an edge, a root transition or a shaded region remains unseen. Perspective changes can also make two images appear to show different areas when they substantially duplicate coverage. The reviewer needs a blade-surface map or equivalent clear representation of examined and unexamined regions, rather than infer completeness from the length of a photo gallery.

Check whether the target could be seen

Motion blur, glare, exposure and image resolution affect detection even where a region appears in frame. A broad erosion patch and a narrow line do not require the same optical evidence. Visual drone imagery does not establish the condition of every internal composite layer. DOE discusses the separate role of subsurface inspection, supporting a method-specific conclusion rather than an unqualified statement that the blade passed.

If one face has glare throughout the survey, repeated images of that face may not add valid coverage for a fine-line concern. The provider should explain whether the target feature could actually be seen there and how any unresolved region will be handled.

Use the gap to specify follow-up

Ask the inspection provider what additional approved view or method would resolve the particular unobserved concern. Drone operation, aircraft permissions and turbine state require the appropriate competent planning; this page gives no flight or rotor-positioning procedure. No MARSTON drone inspection feature or universal defect-detection accuracy is claimed. The useful outcome is bounded physical coverage and a targeted next examination where the evidence is insufficient.