Ian W:
Overall the more controlled certification level testing is far more efficient and complete in a ground test than in an unpredictable and limited air test.
Exactly. I'm hoping that Boeing/Thales/GS Yuasa/Securaplane will continue lab testing until the nature of these failures and the battery system characteristics are fully understood.
Unfortunately, I suspect that once Boeing gets the fireproof box solution certified, the battery problem will be put on their back burner (figuratively). The knowledge gained could be used to produce a better design for the next derivative or model.