Originally Posted by franklin_m

Not questioning the see and avoid, depending of course on good lookout doctrine, good visual acuity, etc. Reality is, if someone is flying a high speed expensive sUAS, they're probably watching it and not the airspace all around them. That's where spotters come in. But most of the spotter video I've seen shows both of them watching the same model, which means neither is really scanning the sky in all directions.

With respect to complexity, my comment was a simple thought experiment.

Scenario 1. Say you have a four channel sUAS, and there's maybe 12 single points of failure in electronics: Battery, battery connector, switch, receiver, four servos, and four servo connectors. Say each of them has reliability less than one (i.e. imperfect, so some degree or another). You now can calculate a reliability figure of merit.

Scenario 2. Now say you look at more modern sUAS with multiple batteries, multiple battery connectors, one or more switches, a power distro box, 10-12 servos, 10-12 servo connectors, fuel control, and some stabilizer unit. Now you've got some number of single points of failure greater than the simple example. We can argue that some of the individual components are more reliable, but I don't think it's unreasonable to say the reliability of the entire system may well be lower. And worse yet, some of the failure modes are latent and may not be known until after a crash. NASA found that out the hard way - not once but twice. Not an exact quote, but one of the mishap investigation senior members famously said: "Complex systems fail in complex ways."

That was the basis for my comment.