Have had great results so far with the HE.EN folding blades - did have some doubts when we ordered (mainly due to HE.EN site-page being similar in aesthetics to a middle schooler's attempt at webpage design) but was pleasantly surprised by the build quality and design. It's clear the company decided on the Swiss Approach - very well thought out and designed in regards to aerodynamics and also efficient stowing.
We had to modify several GPC carrying cases to make room for the hub attachment points and the blades fit extremely well with minimal movement during travel (the blades came with four foam locking attachments per set for use during transit, but we lost those in just under two weeks. No surprise there, the foam pieces are small-ish and according to the guys that lost it, 'random few chunks of foam easily misplaced - probably rode low level air currents during pre-flight testing... to the Maldives'). We CNC'd somewhat H-shaped locking attachments out of commercial plexiglass, and they've worked fine so far.
My operations team and I were also initially concerned about the folding stress points and their operational / operating tolerances - half expected them to shear off during high power maneuvers in gusty wind conditions (20 - 35 knots at an altitude range of 30m - 70m by pilot's estimate over the Indian Ocean). They didn't shear off thankfully - however, we noticed significant negative control issues in the yaw and pitch department including extremely noticeable shaking occurring at all four engine mounts. Of course, winds aloft in those locations tend to pack slightly more punch and should not be attempted to be flown in unless you had a good reason to.
My main concern at that point was the high probability of the
i2 flipping over and going for a kamikaze run. Switched to ATTI as soon as the first problems started, trained and experienced pilot being a lot better than possibly malfunctioning equipment. GPS lock in those situations tend to dig the proverbial hole even deeper - overcompensates for less than optimal flight control in high wind and you're left with an even slower to respond flight system. Had to rapidly lose about 40m in altitude within 2 - 3 seconds in order to regain nominal control. Lots of back and forth between team members as to why it happened etc etc, but I'm not going to get into the details of that right now.
We submitted the drone and props to a specialist in structural stress testing - mostly in part to the CYA theory, but also just to be thorough. I'll probably post his results when I get them, on this thread.That being said, we only have had that problem with those four specific blades. Our other
Inspire 2 units running the same prop setup have had no such problems, but then again we haven't flown in 30+ knots yet. And sorry for the somewhat long spiel, tend to do that when thinking of '**** hitting the fan' events.