PPRuNe Forums - View Single Post - 787 Batteries and Chargers - Part 1
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Old 28th Jan 2013, 21:40
  #244 (permalink)  
RR_NDB
 
Join Date: Feb 2011
Location: Nearby SBBR and SDAM
Posts: 873
Testability issue

Hi,

old dawg and EEngr

Both comments makes me remember on Testability. I was concentrated on that issues on System, PCB and IC (LSI) level during many years. And i always had a great interest because worked before in Maintenance where i observed many difficult situations and even some unexplained facts "coming from design". Actually i designed for Testability, many items.

Both comments from you make me present the questions:

1) The batteries were subjected before to the same (routinely) conditions the 787 fleet experienced? Or even more demanding (routinely) concerning charging current, discharging current and temperature?
2) Are these batteries being exposed TODAY to this conditions in the Lab? (Yuasa or Thales) Or we would need to analyze the 94 remaining batteries.
3) In this case WHO would lead (and pay) the work?
4) The new battery (first use as main in an airliner) was equipped with enough data logging in order to analyze itīs performance after incidents or accidents?
5) Considering the current batteries are not just "cells in a package" how to manage the required work to explain WHY both cases happened?

Time is the only Testability "solution" really effective*. We never know how new components will perform in real life. Time proven parts are required in critical subsystems.

The Test Engineers responsible fort he new battery so important for a ~ US$40 Billion program indeed had a very complex and important task.

And the Decision Making (inside Boeing) was a critical, very critical one.

I hope someone is properly testing the Thales batteries right now.

(*)Yes, i know the JAL (main) battery was very young.

It would be interesting to see if the same is happening now. That is: Does the NTSB receive data from the actual responsible parties directly? Or does it have to work its way through both the contractual and international regulatory maze?
Could this be a cause for a virtual stalemate? And prolonged grounding?

TURIN, important detail. Will comment in few minutes!
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