Each blade carries several defect markers of random size — a few large, already-obvious cracks and several tiny early-stage pinholes or delamination spots. In ground-based mode, a fixed technician camera far below can only resolve defects above a size threshold: small ones stay invisible and silently grow a little every inspection cycle until they cross the threshold — or worse, cross into critical failure risk. In drone close-inspection mode, a small drone visibly flies a path that hugs the curved surface of each blade in turn; its onboard camera is close enough to resolve every defect regardless of size, flagging and "repairing" each one before it can grow.
- Ground detection threshold — how large a defect must be before it is visible from the ground; raising it makes ground inspection even blinder to small damage.
- Cycle length — how long one simulated inspection pass takes; each completed cycle grows every undetected defect a little.
- Prevented failures — tallies defects the drone caught while still small (below the size that would have eventually caused structural failure).
Real-world relevance: turbine blades can exceed 50 m, so a ground survey (naked eye or binoculars) genuinely cannot resolve millimetre-scale cracks or lightning-strike pinholes at that distance — only close-range, high-resolution drone imagery can catch them while they are still cheap and easy to repair.