I think multirotors have the capability to be made quite safe. The only moving parts are the rotors, and with higher rotor counts, graceful degradation of flight performance is possible in the case of a rotor-out.

Problem is that most of the components (batteries, motor controllers, flight controllers) are built by and for hobbyists. Motor burns a winding? ESC spontaneously lets the smoke out? Whatever, they're $15 bucks each. The field of "commercial grade cargo multirotor" is still in its infancy. The balance of safety and cost for the components hasn't been struck in the market. You either deal with random chinese components and control algorithms written by intrepid RC airplane nuts, buy very expensive industrial/aerospace grade components, or roll your own solution.

Hexes and octocopters are "safer" than quads - since they can (with appropriate controllers) cope with any one motor/controller out, and some combinations of multiple motors out. (Anyone flying expensive DSLR cameras uses these for that reason.)

There are some quad copter controllers that try to deal with single motor failures, but they're mostly experimental (at least on the hobby end to the space) since they need to be able to reverse a motor, which most motor controllers used in these applications are not build to do.

I recall a quadcopter control mode that spins the entire craft quite rapidly, exchanging yaw control for altitude control.

Found a vid: https://m.youtube.com/watch?v=bsHryqnvyYA

Without even clicking that I knew it was gonna be ETH Zurich... They do pure magic. Pretty much nobody _else's_ quadcopters can survive a motor failure... (But it'll come, presumably. Amazing software is cheaper than redundant hardware, after all...)

Not to detract from how cool this work is but the preconditions for this to work are quite far-reaching. It is based on bridging the reality gap by having that gap approach zero - by removing error sources from the real world rather than model and account for them. Same goes for other ASL work.

I don’t expect a service delivery company to use hobbyist components. That’d be s recipe for disaster. One would think they’d put something like this though its paces before testing it out in public. I’d expect they buy aerospace grade components where possible and build their own to spec where needed.

I fully expect most "service delivery companys" to buy their drones from the same Alibaba vendors that share bike ad scooter companies buy from...

Losing them, crashing them, having people steal them or throw them in a lake - those are things to include in your VC funded "operating costs" and to mitigate/offload the risks in your TOS...

(Small print: "The delivery customer shall be wholly and solely responsible for any damages and costs incurred by their delivery and any company equipment used in the completion of the customer's delivery, including but not limited to the drone crashing into a playground full of children." Just like Tesla's abrogation of responsibility when their "autopilot" software is driving the car they sold you...)

Not sure how things work in Switzerland, but at least in the US I think these aircraft would be under the purview of the FAA who likely would require some rigor. Likely something similar in CH.

The market is too young for this kind of process. Regulators around the world are smart enough to realise you can't expect drones to follow classic aeronautical design and safety processes right now, you would just stop dead the whole field.

So while they gently introduce such rules (mostly centered around see and avoid for now, also identification), the main way they use to ensure safety is restrict where and who can fly them.

You know they can't be trusted, so you don't fly them above sensitive areas. As processes mature, reliability increase and trust is gained, you will see drones expand the airspace in which they are allowed. It's already happening for BVLOS (beyond visual line of sight) flights which requires a waiver from the FAA in the US (with paperwork such as risk assessment, collision tests on mannequins and so on), as well as specific equipment/processes.

These aircraft are in fact manufactured by a US company (Matternet).

There's no aerospace grade for most of the components. It's either custom made for the most critical/unique components, hobbyist parts (who else needs 4" propellers), or cots that are designed for other applications.

Pretty much no one besides DJI has the scale for custom made, except on a few select components. Drones are still in their infancy, those companies are still trying to see if they have a business model and improving/creating technologies. You can't expect mature processes from this environment.

In a sense, most other aerial vehicle types are worse. Helicopters, with only one main rotor are incredibly complex machines requiring constant maintenance. The rotor blades are articulated to provide flight control. Quadcopters are a ton simpler because their rotors are "just" rotors, and flight control is achieved through differential thrust, not angling the blades. On the other hand, helicopters often seem to deal with engine failure better than quadcopters or even fixed wing aircraft.

Fixed wing drones have the big problem that they need to go fast to stay in the air. Which requires a lot more motion planning.

Your typical helicopter is made to entirely different standards than your typical drone.

Yes, of course. But toy helicopters have been around for a lot longer than quad-copters have been popular. And I've not seen a lot of people using single-rotor RC helicopters for filming and delivery (I'm sure there are some ...).

My point is that multicopters are a lot simpler mechanically. No articulation, no transmission, just propellers on an electrical motor, controlled by pure electronics with no mechanical components in the loop except the drive coils.

Arguably multicopters are easier to control automatically (with modern electronics), though that wouldn't be THAT big a factor today, I guess.

Also electrical engines can deal a lot better with variable load and RPM. Multicopters with combustion engines (driving the rotors directly, not through a generator) seem to be quite uncommon.

Still, if multicopters are supposed to be routinely used in the presence of people, they need similar standards of maintenance and failure control as would bigger aircraft, be they manned or unmanned...

You're not wrong, but even model helicopters can autorotate: https://www.youtube.com/watch?v=bxQ5kwqiPN4&t=135