The untold story of QF72: 'psycho' automation leaves pilots powerless
smh.com.au
smh.com.au
> how can the plane stall and over-speed at the same time? The aircraft is telling him it is flying at both maximum and minimum speeds.
Stalling is due to angle of attack, not speed, and it is possible to overspeed and stall at the same time. Though admittedly not while flying straight and level, in cruise, as they were here.
> In the Boeing 747 jumbo – the backbone of global aviation for almost five decades – pilots' control sticks are connected by wires and pulleys to parts of the plane such as the tail.
Pretty sure the 747 was all hydraulic.
If this can happen in a multi-million dollar airplane that has 3 computers, it is no far stretch to see it happening with self-driving vehicles that only have 1 - and much less R&D. The upside being you're not 35K feet in the air.
There is a phrase I like to murmur to myself that I think is applicable here: "Apple knows best". As of late, Apple has made numerous technology and software decisions that I find quite disagreeable. And many of these have, in fact, significant implications for myself, consumers, and their products overall. But "Apple knows best!" In their infinite wisdom, they call all the shots, good and bad. And if it's a bad one, which to me many are... you suffer with no recourse, because there is ONLY their way.
I feel this relevant because one of the main issues the pilots faced is that the computers are above them in command. They are authoritative - and so don't reveal things to their underlings. In a computer system that is meant to have no single point of failure, they neglected to realize that the computer system itself is a single point of failure. This means the designers of the airplane, purposefully removed control from pilots and gave them no recourse or alternatives.
These are the lessons we need to learn from. While automation of flight has improved safety and reduced human error, it does not allow for humans to reduce automation error. In symbology, the two can work together to improve safety even more, as this article makes clear. With better communication from the computers to pilots, and better ability for pilots to seize control from systems that are misbehaving, there is a greater chance for success.
But I think this solution is in contrast of where the industry wants to go: to remove pilots entirely. And for the bottom line of airlines, that's pretty dreamy. But at what cost to potential lives saved? If QF72 was solely automated, this would have been a very different story.
While I prefer Boeing's approach to Airbus's, the above statement isn't true. Airbus aircraft do have an Alternate Control Law (less flight envelope protection) and Direct Control Law (no flight envelope protection). These are in addition to the Normal Law (full protection), which is similar to what you describe, as well as a mechanical backup.
The aircraft is designed to automatically revert to more-manual control when sensors return unexpected values--and that's what happened to AF447. In that case, the computer recognized strange AoA readings, so it reverted from Normal Law to Alternate Law. The pilots, being insufficiently trained in the use of Alternate Law, stalled the plane into the ocean because they expected the plane to override them in the case of a stall.
Pilots also have to option to manually revert to Alternate, Direct, or mechanical control by pulling the appropriate circuit breakers in the cockpit.