Cockpit Confusion
Smiling Ed and Rudderrudderrat – you are patient and well spoken. I like your style.
I am a pilot, though just VFR, and wouldn’t presume to compare my piloting skills with yours or most of the contributors on this site. I do, however, know a thing or two about IT and implementing automated systems. I am not anti-Airbus, anti-Boeing, or anti-anything else. I am pro-arrival-at-my-destination. IT has taught me that thoroughly tested software can – and does – go wrong, and that just because something can be automated doesn’t mean it should be. Critical systems should, IMO, allow human beings to interrupt the automation when appropriate; i.e., “Give me the speed even if it is below your threshold!” or “Give me the AoA even if it is unreliable!” Perhaps that would have helped on AF447.
My hope is that the authorities will consider how decisions made years ago led to some of the confusion in the cockpit. There apparently was a mindset years ago – later reconsidered - that stall was no longer an issue. Did that misplaced confidence in automation pervade the builders and operators? What (if any) other design features are based on the assumption that automation will prevent bad situations? Several people have commented on design and training issues in which pilots lost to IT or bean counters (or perhaps other pilots). These include the stick issues including simulated feel, the lack of AoA indicator, visibility of pilot actions, etc. Dissecting how the old decisions were made, and whether they were good or bad, would be a good lesson in organizational dynamics. I also wonder:
1. What led to the decision to disable SW and displays below certain angles and speed thresholds? Several have said the AoA vanes work fine down to a light breeze. Were 30 deg and 60 knots (IIRC) chosen as limits because out-of-range values are unreliable or because the software would “protect” them from that situation?
2. Why no audible auto-trim? That seems quite an oversight to this novice. A lot of training emphasis was placed on avoiding manual trim. Did the designers think trim – like stall – was a non-issue? Maybe someone felt an audio feedback would just encourage pilots to be more aware of trim, and that was presumably a bad thing. The software, after all, would make that a non-issue.
3. What led to all the laws? The mixed-mode operations and varied levels of degradation seem confusing and counter-intuitive. I read it in the comfort of my chair with tequila at hand. How would it feel to be handed this situation at altitude, mid-Atlantic, 200 souls on board, improperly trained, for the first time?
IMO, too much false confidence in a number of areas led to the disaster. Designers were confident of “protections” that didn’t cover all the bases. AB failed to appreciate the significance of the pitot failures and the risk of simultaneous loss. AF was unable/unwilling/unaware re training issues. The gentlemen flying the aircraft were handed a basket of snakes. I’m not qualified to say anything about their actions, and hope never to be handed a situation like that.
Pardonne-moi pour le poste de longue.