Originally Posted by HazelNuts39
At first sight, this would seem to be preferable to the BUSS in an UAS situation. What are the disadvantages?
It's wrong! Who wrote that? I did?!? Oh well... What I wrote was very simplified, and most probably oversimplified, illustration of the way low speed cues work on modern EFIS aeroplanes, without the need to know what's the actual weight. It was not meant to be taken literally as be-all and end-all definition of system operation. I strongly suspect your further line of thought, about showing wrong stall warning speed when IAS gets unreliable is correct and covers the reason why low speed cue gets shut off when IAS data is lost. BUSS is basically the same thing you are proposing: replacing IAS with AoA information. If someone said that having AoA display is great because fighter jocks use it would have shown impressive misunderstanding of the way things work in aviation. Yes, combat pilots of last thirtysomething years usually do have a little gizmo making their life easier during approach and landing, it's either doughnut & chevrons type AoA indexer or AoA bracket on HUD. It is there to make their already complicated life easier by reducing the need to accurately calculate their approach speed for actual weight plus any effect from external stores. No, it is not 100% reliable as AoA vanes do get stuck or birdstricken then it's reversion to monsieur Pitot again. Of course, one has to be proficient in its use, which can only be achieved through practice. It is of utmost importance to know that yellow light means stick back, red stick forward, not the other way around.
In transport aviation, we are more concerned with field and cruise performance maximization than with the shooting down the intruders or bombing the bunkers while dodging the flak. We're not great buyers of AoA gauges as airspeed indicators let us do that part of our job more precisely. What we do when we lose IAS and there's no AoA gauge to save our flying butts? We (well, most of us, most of the time) revert to old fashioned discipline, taught already on the basic trainers, called "pitch and power". I had to demonstrate safe visual circuit in C-150, with ASI covered, just using pitch and power to get my PPL and I'm pretty sure it wasn't just me.
Originally Posted by Rudderrudderrat
The Airbus side stick system lacks the "position of the control surface feed back loop" to the pilot.
Uh-huh. I can only imagine the rage, fury, indignation of the "If it ain't Boeing, I ain't going" brigade when Boeing abandons simple stick-to-control flight control arrangement and replaces it with hydraulic monstrosity that requires air data driven artificial pitch feel to be effective. If the day comes, we'd better hide the fact from them manual control freaks, lest we risk the riots.
Originally Posted by Organfreak
Cost should never trump safety.
In ideal world. I like better this one, it's more realistic:
Originally Posted by Author unknown, please help
Safety begins as a perceived value of human life
It's wonderfully politically incorrect yet it perfectly explains regional safety statistics.
Nevertheless, suggestion that Airbus FBW raison d'etre is cost and that cheaper must be less safe is completely misinformed or an indicator of recklessly pushed agenda. Or both.
Originally Posted by CONF iture
If I had to enter that flight deck at that time, the first obvious clue would have been that full back yoke at 350 ... now call me unprofessional.
Is this really what you're trying to do? Eliciting certain reaction? Well, it's nothing personal, but IMHO airline pilot who enters the flight deck in night IMC and does not look for the clues on the instrument panel displays unprofessional behaviour, definition of which is not entirely arbitrary as not adhering to professional standards in aviation can be lethal.
Originally Posted by CONF iture
Sidestick Airbus concept suppress information of great value for a crew : It is a fact.
It is not a fact; it is an opinion. In natural and technical sciences, opinions do not become facts just because some anonymous posters or mediapersonnae repeat them ad nauseam.
Now find me someone who really is an expert on the aeroplane flight controls and who can coherently, reasonably and non-anonymously state what you have written.
Originally Posted by CONF iture
What is more sensible and necessary, is to openly discuss what the sidestick Airbus concept has suppressed. It is the role of Airbus, it is the responsibility of the BEA. But Old Carthusian can sleep well, never the BEA will approach the subject, far too sensitive, and if ever they do at my great surprise, it will be to better discard it as a contributory factor.
... Report in June ?
Completely unnecessary ad hominem directed at Old Carthusian.
Anyway, BEA or any other safety agency does not give a rat's stern about PPRuNe or any other anonymous pilots' forum. Those who are not on PPRuNe to "elicit certain reactions" and thus receive their pay through others' responses, but rather really seek an improvement in safety, should submit their concerns direct to BEA.
However, there are two problems: you can't submit your theory anonymously. Second is that theory that in multi-crew enviroment, the assisting pilot must always know what is the control position of the flying pilot runs afoul of the basic instrument flying model of closed loop feedback via instruments, so there's good chance BEA will simply bin the submission. Of course, some sensitive souls might see it as an evidence to conspiracy.
Originally Posted by Lyman
The evidence is yelling at you.....
Nope. The evidence, so far, has been neatly and unemotionally put down in the three interim reports. Only ones yelling are those PPRuNers who are taking some evidence out of context and ignore lots of other to push their own unsubstantiated view on the matter. Seems that some are preparing to pour their indignation on BEA's findings when the final report is out. Certain Teutonic gentleman has already warned us of such an approach:
Originally Posted by Friedrich Nietzsche
The worst readers are those who behave like plundering troops: they take away a few things they can use, dirty and confound the remainder, and revile the whole.
Anyway, there were 32 cases of at least two pitots blocked on 330/340 before AF447. Did we discuss them here on PPRuNE?