Apparent electrical failure cascade on Ethiopian 787

[Evan]

Not clear as to whether the alerts were false or not, but what a day these pilots had.

http://avherald.com/h?article=4a0bf60e&opt=0

Landed safely.

[ATLcrew]

I know I'll probably regret this, but I'll ask anyway: why do you think these pilots had a particularly bad day?

[Evan]

I know I'll probably regret this, but I'll ask anyway: why do you think these pilots had a particularly bad day?

Meaning a pretty stressful one. They seemed to have handled it very well in spite of that. Redundancies apparently held up. I'm very interested to know what exactly went down here, and why.

[3WE]

...why do you think these pilots had a particularly bad day?

I know I'm not_Evan but I'd put a beer on the following:

1) It's generally not_fun to have your schedule disrupted.
2) Unless you are Boeing Bobby, your cargo can be sooo gripey.
3) I know a pilot who likes to cite paperwork as one of the major headaches to many incidents.

[Evan]

I know I'm not_Evan but I'd put a beer on the following:

1) It's generally not_fun to have your schedule disrupted.
2) Unless you are Boeing Bobby, your cargo can be sooo gripey.
3) I know a pilot who likes to cite paperwork as one of the major headaches to many incidents.

4) AFAIK, the failures indicated in the report might cause moderate in-flight cockpit anxiety as well.

I'm not as well-versed on the 787 systems as on other Boeings but from what I do know, I think the loss of both BPCU's (bus power control units) means you can no longer reconfigure busses for APU or backup power. I am very interested to know if this is accurate but it is based on Boeing literature. I think the loss of both BPCU's is considered a very remote possibility. In other words, I think it is a serious incident.

The other failures listed in the report are covered by redundancies. Each engine has two EEC channels. Each engine has two GCU's. So every fault listed there would add up to a fail-operational situation. It is strange that the EEC channel failed on the left engine and the GCU failed on the right one (unless they mean the right-hand GCU of the left-hand engine). That, plus the "multitude of system messages" and "other associated malfunctions" sounds like either a failure cascade or a fault affecting multiple systems located in a common area due to a common cause (like electrical arcing/fire).

Or maybe simply a failure of the reporting/indicating system...

[ATLcrew]

Or maybe simply a failure of the reporting/indicating system...

That what this sounds like to me, some kind of a FWC failure.