I think autopilot confidence-mood light should be placed on such vehicles. This way you could predict what is going to happen with the vehicle.
The autopilot losing enough confidence and wanting to be turned off should blink between two colors and sound an audible alarm until the pilot presses a button to acknowledge the autopilot wants to turn itself off.
What they didn't know was:
1. Exactly why the autopilot was having trouble, and
2. That the fly-by-wire/flight envelope protection system had switched to "alternate law" mode which disabled stall protection.
Which AF447 did, IIRC.
The captain woke up eventually, returned to the front to check out what was going on, and then trusted his pilots to explain to him what was going on. Unfortunately, one of his pilots was incompetent and his actions was confusing the other (actually competent) pilot.
The issue is that the ignorant copilot didn't know the issue about stalling out, nor how to get out of a stall. It takes specific training to pull a plane out of a stall. It goes against human instinct (you have to push the plane down, THEN after certain velocity is reached, pull up later).
The competent pilot was overruled by the incompetent one (the incompetent one was in the primary seat). The rest is history.
Pulling up immediately is the human panic response that needs to be "trained out". And its what one of the two pilots did in the situation.
AF447 had ice-clogged pitot tubes, and the pilots lacked reliable altitude and airspeed info. Redundant sensors reported conflicting data. The flight control system dropped back to "direct mode", where the control stick (which is a little joystick-like lever) directly moved the control surfaces. In that mode, pulling back the stick stalls the airplane.
Hitting the pilot with a mode change like that in the middle of an emergency was part of what caused the disaster.
"High AOA protection is an aerodynamic protection: The PF will notice if the normal flight envelope is exceeded for any reason, because the autopitch trim will stop, the aircraft will sink to maintain its current AOA (alpha PROT, strong static stability), and a significant change in aircraft behavior will occur.
If the PF then pulls the sidestick full aft, a maximum AOA (approximately corresponding to CL Max) is commanded. ...
If the angle-of-attack still increases and reaches ALPHA Floor threshold, the A/THR triggers TOGA thrust and engages (unless in some cases of one engine-out)."
What this says is that, in normal law, pulling the stick all the way back will give you the maximum pitch currently allowed, and if the pitch is higher than that, the engines go to full power automatically. That's a stall recovery.
But AF447 didn't have good sensor data for airspeed. That disabled this automatic recovery capability. (There are alarms and displays when this happens.) With the control system unable to assist the pilot, pulling the stick all the way back was totally wrong. Also, the AF447 pilots thought they were in an overspeed condition, while in fact they were stalled.
(I'm not a pilot; I used to work for an aerospace company.)
From Flying Training: "Stalling will occur whenever the critical angle of attack is exceeded, irrespective of airspeed. The only way to recover is to decrease the angle of attack (i.e. relax the back pressure and/or move the control column forward)."
This is referring to the aerodynamic stall, which is what caused AF447 to crash, not an engine stall.
I'm not an Airbus driver, but it's my understanding that normal law provides stall protection, and pulling the stick full aft will give you the highest angle of attack consistent with not stalling the aircraft. This is what is being discussed in the paragraphs you quote. It is, however, possible to stall the Airbus in alternate law, in exactly the same way as it happens in any other aircraft. AF447 was flying in alternate law.
In summary: increasing thrust is not what breaks the (aerodynamic) stall (but it is used to minimize height loss). Reducing AOA by pitching forward breaks the stall, and that is done on an Airbus by pushing forward on the sidestick.
Airbuses are weird beasts though, and I have to say that as a pilot I find the normal stall recovery procedure to be completely counter intuitive. The compounding problems with the pitot tubes being iced over plus seeing St. Elmo's Fire due to improperly routing the aircraft directly into a thunderstorm certainly didn't help matters.
Huh? Where? Googling doesn't reveal anything that seems to jive with what you're saying.
https://www.google.com/search?q=airbus+a330+stall+recovery+p...
Perhaps what's happening is that Airbus realized in the aftermath of AF447 that the idea of "pull up, the airplane will do what's right to save you" wasn't a good one and changed their training materials. I don't know for sure as I'm not terribly familiar with Airbus. I do think that the whole input averaging is an awful idea though.
That's true, but mostly because the guy flying AF447 wasn't a "pilot", he didn't understand how to properly fly the aircraft. Like most Airbus pilots, he was a "system manager" and spent thousands of flight hours watching while the aircraft itself did most of the work. When the automation failed, he simply didn't know what to do to fly the plane by hand.
From what I've read (and I'm not a pilot either), the proper response to unreliable or conflicting airspeed data for the A330, when you're at high altitude (not trying to land or take off or anything like that) is simple. It's something like:
85% power, wings level, 5 degrees nose up pitch
Of course, it is a stretch to ask airlines to either hire competent pilots, or at the least to periodically put pilots into stressful situations like that in the simulator. They won't do it because simulator time is too expensive. It's more cost effective for Air Chance to lose an occasional plane than to make sure they have competent and trained people in the cockpit.
Unusual Attitude Recovery [0] in suitable aircraft (L-39 jet trainer is somewhat common) has been made available to airline pilots.
They do make airline simulator sessions somewhat stressful for airline pilots. Capt. Robert "Hoot" Gibson called it "death by simulation" when he trained to fly the Space Shuttle. They still gave him a workout in the simulator to fly a Southwest 737.
The problem is that when there's the pitot-static failure the VSI (generally) indicates by "sticking" wherever it was when the failure occurred.
"Speed" means a different thing to a pilot than it does to a non-pilot. Groundspeed is irrelevant (aerodynamically), airspeed is everything. To sense "overspeed" you have to know airspeed. And since airspeed is a measure of the movement of the aircraft relative to the medium it's moving through (air), there has to be a system to measure that movement. That system is the pitot-static system. The pitot tube sticks into the uninterrupted airflow, usually on the wing somewhere, the static port sits where the air is calm, usually on the fuselage. The airspeed indicator in particular relies on the differential between the two inputs to determine airspeed.
Here's the best non-pilot friendly article I could find that explains what happens when the pitot-static system fails: http://www.boldmethod.com/learn-to-fly/systems/airspeed-indi...
I'm a former pilot, PPL with a few IFR lessons, and I'm pretty rusty on this stuff so while I'm pretty sure I'm accurate here YMMV. :)
The original OP post is about automated systems should not crash into an obstacle even if a driver summons it to do so. The AF447 article builds up a great story of error upon error, but I think the root cause was a captain asleep or too groggy at the wheel. Given the Airbus's safety record, I think it is ok to say the automation has most likely saved more lives than if we were 'pilot only' at this point.
Relevant: I am a licensed pilot and am very familiar with the NTSB and similar agencies that do post crash analysis. They are among the most thorough and most scientific and objective inquiries that exist in the modern world.
You're making really serious allegations against actual people that are wholly unsupported.
I am not sure what the NTSB has to do with the remarks I made. If anything, the head investigator relayed supporting allegations to the Vanity Fair author. Here is a quote from the article [1]:
>>The chief French investigator, Alain Bouillard, later said to me, “If the captain had stayed in position through the Intertropical Convergence Zone, it would have delayed his sleep by no more than 15 minutes, and because of his experience, maybe the story would have ended differently.
>>But, it became known, he had gotten only one hour of sleep the previous night. Rather than resting, he had spent the day touring Rio with his companion.
I accept that you are a licensed pilot. I am a technical diver, with many hours underwater fixing hydraulic and electrical systems, dealing with emergencies like hydraulic fluid leaks, and emergency repairs. I am use to tight situations, however, I am not an underwater accident or incident investigator, and my diving credentials only give me some insight into those types of incidents, that's it.
I have also checked other news accounts, and the off-duty flight attendant allegedly his mistress based on his own emails uncovered by investigators.
More from the Vanity Fair article:
>Marc Dubois, 58, was traveling with an off-duty flight attendant and opera singer. In the French manner, the accident report made no mention of Dubois’s private life, but that omission then required a finding that fatigue played no role, when the captain’s inattention clearly did.
I am not saying the static pitot tubes freezing had nothing to do with it, as obviously this was the kick-off to the problem. I am addressing the article, which engagingly enumerates the steps from how an equipment malfunction escalated to human error, and subsequently the associated behaviors and responses to an airline crash.
[1] http://www.vanityfair.com/news/business/2014/10/air-france-f...
I think this is an excellent idea. Soft blue lighting (or whatever) while it's driving automatically, soft green for manual, angry pulsing red for "human I need an assistance now".
If we are serious, I feel much more useful would be provide a range (let's say percentage 0 - 100%) of confidence.