[Timothycquinn]

I don't think that Lillium uses variable pitch blades. Also, using multiple fans will lower the chance of catastrophic failure due to loss of one or more fans. For example, A system with only four fans would mean loss of a single would be truly catastrophic.

If Lillium uses multiple battery packs and redundant wiring and controls, they could achieve excellent redundancy; to a level much lower than many competing in this space.