I am sometimes flabbergasted by some of the things YC will fund. This is one of them.
I don't know where to start, other than to say I would never make some of these assertions in public. Doesn't YC provide legal support to the startups it funds?
For example:
"Unlike a traditional airplane, it becomes impossible to command the airplane into a stall, a spin, unsafe attitudes, or other bad states."
This is categorically and absolutely false and wrong. There is no such thing as "impossible". Do not ever say things like that or you will find your own words used as weapons against you in the inevitable court case when something does go wrong. Too late now, it's already out there.
Attorney: Sir, your plane stalled and became uncontrollable. The pilot had no controls because you removed pedals and any industry-proven direct control mechanisms. Your company asserted this failure mode was impossible, yet, it happened. Exhibit A, in your own words.
"we can use MEMS gyroscopes that cost Attorney: Sir, your aircraft killed all four of its passengers, destroyed three homes, killed an additional three people on the ground --two of them children-- and sent half a dozen others to the hospital in critical condition. Why did you use cheap sensors instead of industry-standard, battle-tested, fully-vetted, qualified, susceptibility-tested hardware?
"We’ve developed our own control surface actuators"
Attorney (following-up to the previous question): Control surfaces failed to actuate controls as required. You used cheap self-designed actuation hardware that did not have extensive engineering design, testing and qualification pedigree as industry-standard products...to save money...
"own radios and GPS hardware (an aviation grade GPS can cost upwards of $10k, but it’s the same hardware as in a $20 consumer grade GPS)"
Attorney: I repeat the question. Your cheap $20 GPS just killed half a dozen people. How could you justify placing such little value on human life?
"The only real single point of failure is the engine."
False! A triple-redundant design, will, at best, mitigate a single failure and ZERO in the case of common-mode failures. Triple modular redundancy requires, at a minimum: Triple redundant power, triple sensing, triple compute, triple actuation and no common-mode failure mechanisms. Once a triple-redundant system experiences a single failure, it turns into a system with two possible sources of truth, which means it is impossible to know who might be right.
My free advice is to stop talking and get out of this business before you kill people. Seriously. You are not at SpaceX with hundred-billion-dollar budgets launching craft that fly so far away from population centers that they could explode and nobody gets hurt. Before Crew Dragon flew for the first time billions of dollars went into evolving the systems that made it possible.
Then again, what do I know? I could be wrong.