Why is automation dependency encouraged in modern aviation ?

[Vessbot]

Originally Posted by vilas

Again no! I have said it before with AP on or off pilot's scan remains same only difference is with AP on, the AP makes changes and in manual pilot makes changes. With or without AP It's the loss of scan that causes the problem. Mode or no mode, right or wrong mode, you simply cannot make an approch without a periodic glance at the speed. In the cases we are discussing the crew never even expressed a surprise or utter a word regarding falling speed because they never looked at the speed and worse not even the mode. They assumed a mode that wasn't there, they assumed a speed that wasn't being maintained. In both the cases even the go around was not because they noticed speed or the ROD but because they were not reaching the runway otherwise they would have executed a 3 or 4G Landing. In case of Indian airlines they lost their lives because they were nine seconds too late. The engines were spooling up. Somebody needs maintain the parameters either the AP does it, the mode does it or the pilot does it. Nobody is not acceptable.

“No” to what exactly? You say a few things in the rest of your post, all of which are mostly right depending on interpretation, but I don’t see how it relates to mine, in any contradictory way.

Regarding “interpretation,” here’s what I mean. You say that you have to keep up a good scan regardless of AP on vs. off, and “you simply cannot make an approach without a periodic glance at the airspeed.” Taken in the factual sense, that is of course laughably wrong. People can and do that all the time as a baseline default, and accidents like these 2 reveal the tip of the iceberg. But of course you didn’t mean in the factual sense, but rather in the prescriptive sense, or what should be done.

However, as it relates to the cause of these accidents, it is the factual, not prescriptive sense, that is relevant. What do these pilots do, not what should they do. And what they did actually do, is clearly rely on the autothrottles to maintain the airspeed without their brain being in the loop. And had the modes been what the pilots thought they were, (as you say, “they assumed a mode that wasn’t there”) the autothrottles would have done exactly that.

So where do we disagree? What part of my posts, if you can be more specific, do you take issue with?