Originally Posted by
Notanatp
There seems to be an assumption in the article and in the comments that a retrofitted EICAS would have been likely to have prevented these two accidents. How realistic is that assumption?
In JT610, the crew knew they had a malfunctioning stab trim system and they figured out they could keep the plane in the air using MET. They were focused on the stab trim problem but they just couldn't figure out that they needed to shut off electric trim. How would EICAS have fixed this? Presumably, it would have focused the crew on the principal problem (malfunctioning AoA) and suppressed some of the cascading warnings (e.g., stick shaker, IAS disagree) but the crew was already focused on solving the problem. Would EICAS have displayed a "Turn off the freakin electric trim" message?
In ET302, the crew knew they had a stab trim malfunction and they shut off electric trim, but didn't relieve control column forces first. They then knew they were out of trim, but were apparently confused about what to do about it. What would EICAS have added? Would it have displayed a "Don't turn the electric trim back on" message? Or maybe a message "If you turn electric trim back on, trim up fast and then turn it off"?
I understand the general assumption that less noise/flashing lights may lead to better decision making, particularly at the very beginning of an incident. But both crews were past that and were controlling the plane (even climbing in the case of ET302), albeit with significant effort. Isn't it hugely speculative to say that EICAS would have made any difference in the outcome?
Originally Posted by
Notanatp
If you "could have a lengthy argument about [my] statement", then you could probably also summarize so it would be less lengthy.
And it's far from clear why that would be off topic. The thread has to do with reevaluation of 737 safety procedures and the need for clearer crew alerting has been discussed here extensively.
As for what regulators think, it's far from clear from the Reuters article what regulators think about the role of startle and workload in the accidents. The actual quote was vague, and the rest was the reporter's interpretation. As I said, nobody would argue with the general proposition that lots of lights and alarms can be a distraction. But that doesn't mean fewer lights and alarms would have made any difference in these accidents.
A few random thoughts (not a coherent argument).
1. EICAS on its own (on an unaltered airframe) might not make a difference to runaway trim.
2. Implementing EICAS would require detailed fault-tree documentation, which could flag the MCAS dependency on single AOA.
3. Implementing EICAS would offer an opportunity to detect faulty AOA, before passing the data on to MCAS.
4. The manufacturer would be unlikely to implement EICAS, without upgrading a lot of other stuff at the same time.
5. A design philosophy that implemented EICAS, would do a lot of other things better.
6. Adding EICAS would require a separate type rating, and likely better training and documentation.
Edit:
HighWind addressed #3.
Grebe and
Loose rivets discussed synthesised airspeed, which relates to #4.
IMO there is no way that an aircraft that included EICAS, would have the same MCAS/AOA faults and poor documentation.
IMO regulators are concerned about overall safety, not a recurrence of these specific accidents, which are extremely unlikely.