It's an interesting question, because the human nature side of us wants to avoid any tragedy if at all possible. But at some point, we must eventually reach the point of diminishing returns, at least economically. Are there even more electronic nannies and warnings we can throw in front of the pilot to prevent this specific thing from happening? Sure, and they seem pretty easy to implement (if they already aren't... I've never seen the action on the 777 flight deck, so I don't know what nannies are already in place). But soon, you are creating safeguards for really isolated incidence possibilities. Where does it end? How much will it cost? How much MORE complex does it make the already complex systems? And if you introduce another safeguard, how does it impact the safeguards and procedures that are already there? Does introducing it break other things in the chain? There are so many variables to consider.
For instance, in this particular scenario (and I profusely apologize for my complete lack of knowledge on this, and I'd be thrilled to learn): They dropped significantly below V
ref. That leads me to believe one of two things:
- Besides the visual indication on the tape, there are no other obvious indications, audibly or visibly, that they've dropped below Vref, or,
- There are indications, but pilots may occasionally dip below that target speed so regularly on approach (do they?) that the warnings are just noise
Both of those are human factors issues, and pretty easily addressed. For me to take that thought pattern any further, I guess I need to ask the fellas here that fly jeeeeeeeeeeeeeets: do you get any visual or audible indication that you've dropped a certain percentage past V
ref? How often are you glancing down during visual approaches to do an instrument scan? What is included in that scan? All of these questions are coming from a GA perspective, so please understand that. Most GA pilots have an eternity to check all of this stuff, and I know things happen much faster in your offices.
