Originally Posted by Tourist
AirRabbit.
Not entirely sure what point you are trying to make so apologies if I have misunderstood, but re the fear factor in the real world, that is exactly what computers are good at removing. They work the same day in day out.
Incidentally, you are all aware that there are lots of aircraft that currently fly around that cannot fly without the computer working?
ie if the computer fails then it crashes?
They seem to be doing fine. Computers are quite reliable when they have to be.
Hey Tourist – no apology necessary … but I think we’re very likely on opposite sides of this particular point. I know that computers are quite good at doing what they do … and that is they take data and they execute the commands that have been programmed to be taken when the data examined is determined to be of a specifically defined value or value range. Some folks have been very successful in expanding the range of data examination but for all intents and purposes those successes are always limited by the methods used to both gather and submit the relevant data for the computer’s examination. However, it remains true that computers don’t “think” and they don’t “anticipate” … unless, of course, someone preprograms the computer to compare existing data with a history of the kinds of developments that have historically manifested with the same values of the data referenced, and calculate some acceptable level of mathematical probabilities for the development of the same circumstances and then adjust the controls in anticipation of those circumstances developing with the same level of probabilities. Unfortunately, the size of the airplane that would be necessary to house that kind of memory and computing power would likely severely limit the number of passengers that could be accommodated on a typical airliner - and none of this even begins to touch on lightning strikes or EMP kinds of interference scenarios. Just yesterday in Detroit (a major US city) an unknown power outage brought dozens of square miles in the middle and edges of the city to a stand-still for several hours. If a similar problem were to occur while airborne … do we just “write it off” as a Mother Nature hiccup?
And, as for "computer controlled airplanes crashing if the computer quits" … as I understand them, the flight envelope control systems on Airbus aircraft always retain flight control when operating under “normal law,” however, in extreme circumstances, like multiple failures of redundant computers, there is a mechanical back up system for pitch trim and rudder. Instead of this kind of mechanical back-up system, newer Airbus aircraft have an “all-flight-control-back-up system called a “three-axis Backup Control Module (BCM).” Additionally, on the newer Boeing aircraft, the two pilots can completely override the computerized flight-control system to permit the aircraft to be flown beyond its usual flight-control envelope during emergencies.
Regardless of the level of sophistication of any specific computer, its success rate is always going to be limited by the data source, the data sequence, the data accuracy, and the resulting successful submission of that gathered data to the computer. Of course the “computing power” (the speed at which data can be input, processed (compared), and a specifically preprogramed response determined, will be directly dependent on the accuracy of the format of the data to be examined, the number of data sources, the determination of priorities of that submitted data, including those circumstances and potentials that may affect those priorities. Again, whatever the response is to be, that too is limited to what has been provided for by the computer’s structure, and how, and to what, that computer is connected. It is obvious that computer-aided airplane control is here and is arguably successful. But, turning over complete control of those airplanes to a computer or a bank of computers with no human intervention is, in my not-so-humble opinion, still some indeterminable distance in the future – if it occurs at all.