Originally Posted by
Chris Scott
In deference to bearfoil's latest post: one hopes equally that the aircraft will keep the flight crew "in the loop".
Originally Posted by
bearfoil
It is not simplistic, and I am not persuaded that people are not intentionally missing the point. Whatever the "Kind of airplane reverts to the pilots" it is obviously and necessarily one that (needs be) familiar, honest, and responsive ... Review this thread and take note of the old guys who still question this format ??
But the kind of situation you're describing does not simply apply to aircraft of the same or of a later generation than the A330. Two incidents that spring to mind are the Roselawn ATR-72 crash, and the China Airlines 747 incident over San Francisco. In both cases, the automation tried to manage the flight to the best of it's ability until it reached the limits of it's control regimen and handed control back to an unsuspecting crew. In the case of the latter, there was enough altitude to perform a recovery, but sadly in the case of the former there was not.
Allegiance to "one" format or the other is legend, going way back. If there are concrete reasons that give this argument life, (there are), then something is endemically wrong somewhere.
Every technological advance, both inside and outside of aviation, has had it's detractors - it's just human nature to be suspicious of change. That doesn't make either side of such "religious" discussions correct.
Originally Posted by
GarageYears
This aspect of the "conversation" has had me thinking also... since, in everything except Mechanical Backup (a realm of last resort if there ever was one)
I believe the only Western transport category jets to retain such a thing are the 737 and the DC-9 derivatives.
the fact of the matter remains that some interpretation of the crews input the sidestick is translated into a control surface movement - the idea of "Direct" really is a misnomer.
...
Am I reading this right - "max elevator deflection is a function of CG", meaning there are still electronically applied limits to what the pilot can demand (in this case, of the elevators)? Sounds like a "law" to me?
Having finally got my hands on a copy of Davies' "Handling The Big Jets", something leapt out at me when I was reading it - and that is the fact that beyond a certain size, transport category jets are simply too large to have effective manual reversion. Having aircraft "feel" transmitted to the pilots via artificial means is something that has been provided since at least the days of the Comet 1.
What you are describing doesn't sound like a "limiting" control law (in fact in Direct Law there are no limitations as such), but an implementation of precisely this kind of "artificial feel", albeit implemented in software as opposed to hydraulic or mechanical devices.
Davies points out that without these artificial feel units, then it would be possible to very easily fall into an upset and overstress the airframe by virtue of the full authority that powered flight surfaces provide.
Is the Airbus inherently a safer aircraft (not comparing to anything here) because of the FBW system and associated control laws?
In many respects, yes. However that does not make the pilot immune to maintaining situational awareness to the best of their ability.
Whether it is then appropriate to blame the computers for not saving the day seems unfair.
Well, the computers are getting their information from the same sensors as those driving the pilot's instrument display. At this stage a computer is no use as it is outside the parameters within which it was designed to operate - both Airbus and Boeing are well aware of this, and it is for this reason (among others) that there are still two warm bodies in the flight deck of even the most automated airliners, and will continue to be for the foreseeable future.