Originally Posted by
NWSRG
I'm not a pilot (well, only ex-PPL), but I am an engineer, working in safety-critical infrastructure. These two accidents are going to shake this industry. I know the yhave not yet been linked, but the gun is smoking.
Three massive issues stand out for me.
1. What has gone wrong at Boeing, that could allow a system to intervene, unkown to the flightdeck, but which had no redundancy on a vital input? Any systems analysis of this solution should have picked up this critical flaw...if it didn't, then the analysis (or analysors) was patently in error.
2. What has gone wrong at Boeing, that allowed a system to be designed, which used trim as a primary flight control? Correct me here if I'm wrong, but is trim not there to alleviate control forces once a flightpath has been established? Any system where trim is used in a primary manner is completely counterintuitive to flight crew.
3. What has gone wrong at the FAA, that no-one caught this system? It seems they tried to devolve responsibility back to Boeing, but the FAA cannot do that...they are on the hook for this regulatory failure.
Corporate and regulatory culture is the problem here, and it stinks. I've always assumed Boeing were good guys, with a track record second to none. But something has gone wrong. And the FAA? I just find the whole thing staggering.
Pity the poor flightcrew...left with an airplane that had systems they didn't know about, without the necessary redundancy, and which was doing things they couldn't hope to assimilate at a crtical juncture in the flight.
The safest form of transport is facing a lot of questions just now.
One easy explanation to your question #1 is that Boeing discovered this only in flight testing (at least how serious it was) and there simply was no time to make it much better, nevermind redesigning parts of the aircraft, like the size of the elevator surfaces which probably would have cost one or two years additional delay.