Regardless if you work with wind turbines or cell towers, it takes hours for someone to rack up and climb and/or conduct the tedious ground work to perform a proper inspection. Which means you have to make significant trade-offs about what gets inspected.
(Further complicating things, long inspection times mean you’re always working around the weather. And as we all know, high tower work is also inherently dangerous.)
2) Incomplete information
Because typical inspection methods can only access a portion of your total structure, you end up with incomplete, inaccurate, and often, incorrect information.
(On top of that, manual inspections are subjective, every climber is different. This variation makes it impossible to systematically replicate inspections, perform trend analysis, or make critical management decisions.)