Fact is we have no idea the maint history of this aircraft or company safety culture.
No, but sacking the DO the way they did gives us a pretty good clue.
Given the facts known, how, exactly, can the type of operation or motivation of an aspiring airline pilot be a relevant casual or contributing factor in this mishap?
It's not causal to the accident, but it's relevant to the Blancolirio video.
If the underlying hypothesis is there’s only one acceptable level of safety and that’s part 121 I disagree, but we don’t even know if that’s his theory although it could be implied in how he presented it.
I would also disagree with the "one acceptable level of safety". Heck, even the FAA would or we wouldn't have all those other parts to fly under.
However, 121 merely makes it much more difficult to have an unsafe operation. 135 is good, but to be as safe as 121 requires more discipline and desire on the part of the company and its management to be safe. 91 is pretty much the wild west.
Isn’t it true the most dangerous flying is part 91 followed by part 135 then the safest, part 121 using hours flown, mileage flown, passengers flown? By far?
Yes.
You'll find comparing accidents between different segments of aviation, ie., 91 vs 135 vs 121, will not result in any meaningful data for various reasons.
Oh, there's plenty of meaningful data. You do have to work at it though... And I've done that. Pretty much no matter how you slice it, 121 is safer than 135 is safer than 91.
Read about Roger Boisjoly, Bob Ebeling and the rest. Google will give you plenty of resources.
The quote I remember is "take off your engineer hat and put on your manager hat."
Probably and that’s because part 91 flies much slower with less people and usually single pilot? It is less safe, but should we require 4 seaters to have 2 pilots and more maintenance checks?
IMO, It's mainly that Part 91 has less experienced pilots, no requirement for SOPs and comparatively very little oversight from the FAA.
If you want to have a meaningful comparison, you'd have to account for different equipment types as well. I don't think anybody would dispute that an airliner has many safety advantages absent on a Piper Cub.
Jets are safer than turboprops are safer than pistons... But when you look at only within the same part, they're much more similar.
Also, it's quite possible that the reason jets are safer is that they're usually flown by more experienced, two-person crews.
FWIW, twins are NOT safer than singles. In both piston and turboprop, for every accident caused by an engine failure in a single, there's an accident caused by loss of control after an engine failure in a twin.
