In order to fly a number of single rotor units join up with one another to form a viable aircraft. Individually the units are unable to fly but this changes when they join up and co-operate in order to fulfill their mission.
More details - and videos - can be found here.
Damage control: How repairability could help address the e-waste crisis
I wrote a while back about Microsoft´s plans to stop supporting Windows 10 later this year, which along with the onerous hardware requirements to run...