Originally Posted by stickyb
a question for bsieker or pbl. Please excuse if not a sensible question.
Does the non implememtation of the recommendation from the Taiwan incident deserve a specific mention in the WBA?
It is a good question and maybe deserves a note in the introductory comments.
We have given it some thought, but there are a number of reasons why it is not included:
- Information about the addition of a thrust lever warning in the H2F3 FWC version is almost unavailable, and at best circumstantial. The official description of this FWC update does not mention it. Apparently the authorities and/or operators were not happy with adding another bell and whistle to the system, and it is doubtful if it is installed in any aircraft. Maybe someone could verify or falsify this.
- The inclusion of such "Un-Events" follows some guidelines, mainly that it has to be a clear omission of an action or system feature that
should have been performed or installed, but wasn't. Clear indications of this are if the omitted action was (part of) a SOP (such as pulling back both thrust levers), a legal requirement, a system upgrade mandated by an AD, an action that was performed in all previous comparable situations, etc. This FWC update was not mandatory, so the case for including it is not strong.
This guideline, serves to keep analysts from including all sorts of magical/hypthetical "save-me" devices in the graph. Without it one could imagine adding "No manual ground spoiler deployment facility" or "Aircraft does not idle other engine when one reverser is deployed". This is not helpful for the initial analysis.
- it is unclear that an additional warning would have gotten through to the crew in the given situation. Even if the condition for its inclusion above would have been fulfilled, it would have remained an assumption.
Thanks for your comment, good to see that some more people take a look at my analysis. I hope that answers your question.
Bernd