Originally Posted by OK 465
The canard configured Velocity had a deep stall problem initially.
No T-tail.
Nope. It did not.
First, regarding the deep stall, we were discussing airliners, not GA types.
Second, GA canards like: VariEze, LongEZ or SpeedCanard have low wing loading, relatively high speed range (relative to min speed, that is) which necessitates use of large foreplane - compared to wing. Now this foreplane absolutely must be designed so it stalls before mainplane. If it were otherwise, loss of lift at mainplane, combined with still working foreplane woud introduce such a pitching momentum it could tumble the aeroplane end-over-end and that's the issue with GA canards. This tumble is very possibly irrecoverable but is not deep stall.
Third, I am sure that there were numerous witnesses who saw F-GZCP taxi out to her fateful flight and I have strong reasons to believe that not one of them will testify she was canard equipped.
Originally Posted by Lord Spandex Masher
How far above the main wing is the 330 elevator? Is it a similar distance as, for example, a BAc 111?
No. Lower. Further back.
Originally Posted by Lord Spandex Masher
You simply can't confine deep stalls or super stalls to T-Tail only types. It is entirely possible to get a deep/super stall on a conventional (read not a T-Tail) type.
Please provide reference to this statement of yours. I really wonder how is it possible to not put the conventional mainplane below the wing's wake at stall and beyond.
Originally Posted by Lord Spandex Masher
Remember swept wing pitch up?!
Only in the tales of yesteryear, when swept wing was largely an unknown quantity. Since then, wise aerodynamicists came up with something called "washout". When measuredly applied, it assures that roots stall first, thereby: 1)eliminating pitch-up associated with tips that stall first 2) reducing rolling momentum from asymmetric flow separation - separation now occurs closer to CG in lateral sense 3) keeping the outboard ailerons effective. Statement that:
Originally Posted by TTex600
Tips stall first on swept wings, not last. Washout reduces the effect.
was true when Huns were en vogue. Nowadays, on swept wing transports, washout reduces the effect to the point of elimination, as was tragically proven by certain crew of certain airliner that fell flatly into Atlantic without gyrations that have to be expected with tips stalling first
Originally Posted by TTex600
edit: tips stall first on rear swept wings. The X29 featured foward sweep to get around this as does the HansaJet.
In both cases primary consideration was not elimination of wingtips stalling first.
X-29's forward swept wing was intended to direct spanwise airflow towards the fuselage instead of towards the wingtips. While this does reduce the effective AoA of wingtips, with forward swept wing the roots that stall first will cause pitch-up so exacerbating the problem which FSW was supposedly intended to solve.
HansaJet's wing was mid-mounted so there would be minimum fuselage diameter and minimum interference drag from wing to fuselage joint. It got forward sweep so wing centre box would not impede on cabin space. Hansa Jet is T-tailed and stick pusher equipped, therefore her stalling characteristics are of academic interest only.
Originally Posted by RenegadeMan
(the) man-machine interface psychology, economics, politics and big business needing to come clean and invest more dollars into research and training rather than just about this particular crew's lack of ability, perceived or otherwise"
The amount they have already invested in research and training is closer to gigabucks than megabucks. That so far we have no official word that Airbus MMI is sub-optimal or even dangerous boils down to two options a) while imperfect, it really is acceptable b) there's large worldwide conspiracy covering the fact that it really is sub-par and kills people.
Which one to believe? Tough one, ain't it?
Originally Posted by RetiredF4
Manual THS trim (nowhere mentioned in the books except in direct law, and never trained)
Rest of youth post is spot-on, I just have to comment on this. It is not trained because it doesn't work. You can forcibly move the wheel to position of your choice but the FBW will return it to the position it deems to be necessary once you loose your grip and all the while will try to combat the trim with elevator to satisfy G demand.
There's no use and no need for manual trim while auto-trim is working.
Originally Posted by DC-ATE
Why can't we all just admit that if this had been a "conventional" airplane [cable-operated, not computer/electric-operated] that we would not even have a thread on this?!
It is one of the factors but given the contents of the threads we had dealing with AF447 so far, it tells more about ignorance of the posters than alleged complexity of FBW Airbuses.
I suspect that main reasons the AF447 tragedy got so much attention on PPRuNe are a) it involves large body count b) it involves western built and operated widebody c) it involves relatively new flight control technology that is easier to deride than to understand d) most of the posters just can't dismiss the whole affair by using some of their deeply rooted prejudices. If it happened in CIS, they'd conclude it was vodka-caused. If it happened in Africa, it would be corrupt CAAs and shoddy maintenance that doomed it. If it happened in Asia, well it must have been a strong cockpit authority gradient or some similar cultural thing. South America - machismo. Regional airlines - inexperience and poor training. Turkish - exmilguy not well adapted to civvie world.
Well, we're out of prejudices here as it happened to long established western flag carrier. Most of the posters feel that it struck close to home and they can not write it off easily as something-that-can't-happen-to-me. Mental gymnastic they perform to deal with their shock and horror is very interesting thing to behold but its results are not particularly informative.