been doing transmission tower and telecom inspections for a utility contractor for about two years now. mostly using an autel evo ii pro but recently got access to a skydio 2+ for a trial period and the obstacle avoidance is genuinely kind of mind blowing when you're trying to get tight to the steel. that said im not fully sold because the autonomous stuff sometimes does weird things when you're threading through lattice members and it's not always obvious why it's backing off when you think theres clearance.

the bigger question i keep coming back to is how close is close enough for a useful inspection image. like our clients want to see weld integrity, corrosion on the cross members, that kind of thing. right now I'm targeting maybe 3-4 meters from the structure which feels okay but some of the senior inspectors at the utility say they want to see individual bolt conditions which at that distance even with a good sensor you're pixel peeping pretty hard. does anyone push closer than that on lattice steel or is there a sweet spot ive been landing on already without realizing it

also RF interference is brutal on some of these active sites, had a couple scary moments where the compass goes nuts near the top of a loaded tower. just wondering how others are managing that

yeah the RF thing is no joke, ive had similar issues especially on sites with active microwave dishes. the skydio actually handles mag interference better than most in my experience because of how heavily it leans on visual positioning but you still get weird behavior. what we do now on hot sites is basically go full manual with GPS assist turned down or off depending on the situation ? you want a pilot who's actually comfortable flying that way though, its not something you want to learn on a tower job.

for the distance question, 3 meters is honestly where i'd say you start getting useful close-up detail but for individual bolt/nut inspection we're usually pushing to like 1.5-2 meters and that requires a really stable hover and a lot of trust in your platform. the skydio's avoidance will actually fight you a bit at that range around lattice because it sees the geometry as a hazard which is technically correct. some guys i know tape over certain sensors to reduce the avoidance aggressiveness but i'm not going to officially recommend that on a steel tower. unofficially, people do it.

not exactly the same but we do flare stacks and cooling tower inspections and the close pass distance question comes up constantly. for weld inspection specifically we've started pairing the drone footage with a zoom camera on a separate unit ? basically one drone does the wide context passes and a second operator is flying a different bird with a good optical zoom to get the bolt-level stuff from a safer standoff distance. doubles the complexity but your pilots aren't having heart attacks hovering 2 feet from a lattice member 200 feet up. the image quality ends up being similar to a close pass if your zoom optics are decent and the air is calm. wind is probably your bigger enemy anyway on tower work, if its above 15mph honestly the close passes become more trouble than theyre worth and the images get blurry enough that you're doing them again anyway