Another good account of Air France 447, slightly less technical though & focussed more on the recovery effort .
http://www.nytimes.com/2011/05/08/magazine/mag-08Plane-t.htm...
What really happened aboard Air France 447
121–130 of 374 posts
Re: What really happened aboard Air France 447
#122Earlier quoted context omitted.
>at night, over an ocean, in a storm, with no visibility, in possibly significant turbulance Instead of finding out strategies on how to fly under these circumstances, why can't the plane change its course, if they anticipate the flying route to have these conditions. How about running some reconnaissance drones in the popular routes if they suspect a bad weather and want to check out. Or try out better weather monit…
That was the first thing I noted in reading this. Is there any discussion as to why they didn't seek an alternate plan and if not, is this something that needs to or has been remedied?
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Re: What really happened aboard Air France 447
#123Earlier quoted context omitted.
I am a pilot (a small one but instrument rated) - there's no time EVER that you want that, and I am shocked the Airbus does not have a warning that says DUAL INPUT BEING RECEIVED. At the very least, it should give priority to the left seat controls. Was really shocked to read the article.
It does: there's an audible warning that says the words "DUAL INPUT" The English translation of the BEA's third interim report on the flight is available here: http://www.bea.aero/docspa/2009/f-cp090601e3.en/pdf/f-cp0906... It includes the full CVR transcript at the end, which shows that the dual input alarm activated five times.
I think that part of the problem here is that the plane is so far out of trim and CRM has gone completely out of the window that psychologically at least the mental workload on the junior pilot has caused him to "freeze".
Far worse, imaging a situation where one of the control inputs fails; i.e. constantly produces nose up input. Can one of the inputs be suspended / turned off?
Re: What really happened aboard Air France 447
#124I simply don't undersand (or don't comprehend) how the pilots don't know these things. My knowledge of planes is 4 hours of pilot lessons and watching a few documentaries on the Discovery channel yet I know that pulling the nose up of a plane would stall, that when you get bad readings from instruments you cross-check, and that a frozen pitot tube giving bad airspeed readings is very likely in high-altitude storms. I…
Surely there must be more to it. Clearly all of us who've played a flight simulator know that going up too fast will cause you to lose speed and eventually stall and fall until you regain enough speed to stabilize. Sadly in this case it sounds like a mix of overconfidence (not avoiding the storm, trusting the plane more than the stall warnings, not waking up the captain until it was too late) and a lack of training f…
I was thinking about that after reading the report. From our perspective it might be obvious, but we can't put ourselves into that situation.
I wonder if civillian pilots can be trained in the same way as military pilots to handle stresses in emergencies and to think clearly. Or to at least learn something from military techniques
Re: What really happened aboard Air France 447
#125Earlier quoted context omitted.
The articles says it's audible on the recording. Stall alarms are usually very loud. I can't speak for Air France, but in general aviation the word "stall" (in English) is of global significance. I imagine they thought it was malfunctioning, or simply didn't think about it in the heat of the moment.
They don't explicitly state that it is something you can hear in the recording, I made the assumption that the "blackbox" contain not just an audio recording but a log of the computer system -- what actions it took, which is how they know the co-pilot was pulling back the entire time -- and they're basing it off of that. Although the way they phrase it (reading back through the relevant paragraphs now) with the assum…
Surely it seems obvious that if the recorder picks up the crew voices, it also picks up the very loud stall warning?
Re: What really happened aboard Air France 447
#126The state of UX design has advanced so much, perhaps we need more UX testing so that even pilots who are unfamiliar with a plane could figure out what to do. Amazon probably does more with figuring how to help users checkout their shopping cart than plane designers helping pilots get a plane out of a stall. Alternate law and normal law introduces two modes. This breaks one of the rules of user experience, especially…
> how does a plane know it's stalling if the pitot tubes are frozen Angle of attack sensor. AoA is the actual definition of a stall as it measures the point at which airflow breaks away from the wing, reducing lift. Re your other points on computer warnings, cockpits can get pretty noisy when shit happens with various alarms, buzzers, horns and voices going off. There's actually a tendency to reduce the number of dif…
There's actually a tendency to reduce
the number of different alarms and
use screen information to indicate the problem
I wonder if grouped alarms make any sense. For instance you can group all alarms related to stalling together, and present the one thing the pilot can do to correct this. This gives the pilot a sense of what is the most effective use of their attention in a bad situation.
QF mishap - the Wikipedia article didn't talk about the alarms.
Re: What really happened aboard Air France 447
#127Earlier quoted context omitted.
- Delineate command better, e.g. Captain, Co-pilot #1, Co-pilot #2 so that who is in charge is clear. This antiquated idea has killed many more people than it would have saved in this case. Read about CRM: http://en.wikipedia.org/wiki/Crew_resource_management I think a classic example is: http://en.wikipedia.org/wiki/Avianca_Flight_52 The plane crashed because it burned all of its fuel in a holding pattern waiting to…
An additional case that I know about, the Tenerife airport disaster: http://en.wikipedia.org/wiki/Tenerife_airport_disaster Quoting: Speculation regarding other contributing factors includes: The flight engineer's apparent hesitation to challenge Van Zanten further, possibly because Captain Van Zanten was not only senior in rank, but also one of the most able and experienced pilots working for the airline. As a conse…
Wouldn't the Air France 447 crash be an instance where a low ranking officer did not notice errors & was given too much control of the plane, resulting in the deaths of many people?
It sounds like both co-pilots were having mental blocks while operating together in the cockpit. With Bonin stalling the plane, while Robert is unable to figure out why the plane was not responding like he thinks it should & the insecurity of these events leads him to defer to the captain, who is not present.
I am not sure specifying a hierarchy would have helped so much in this case, but the example crashes given in this thread don't explicitly show that the hierarchical structure was the sole cause of the crashes, there were many contributing factors which lead up to both.
Re: What really happened aboard Air France 447
#128I've followed the discussion of the AF447 investigation on several flight discussion forums. The PF (Bonin) apparently never became aware of his angle of attack (once the airplane fully stalled, AOA was absurdly high). He did not seem to be aware that his constant inputs had caused the Airbus's THS (trimmable horizontal stabilizer, horizontal flaps on the tail) to deflect to maximum in order to try to keep the nose u…
What's missing from this article is the fact that the Captain chose to fly right into the storm, saying "on va pas se laisser emmerder par des cunimbs" (in essence: "fuck this storm") http://www.lexpress.fr/actualites/2/actualite/des-dialogues-... This is incredible hubris. Then, in the middle of the storm he leaves the two copilots alone, one of them quite inexperienced, and goes for a nap. He's obviously trying to…
IANA Pilot. I do make aerodynamically correct fixed-wing and lifting-body type paper airplanes, however, and I have had a LOT of fun playing with aerodynamics in this hobby.
One thing to keep in mind regaring stall is that it's 100% dependent on angle of attack, not speed (something Popular Mechanics gets entirely wrong). What happens basically is that at a high angle of attack the air layer doesn't track the wing surface properly and so you are deprived of standard lift. With certain aircraft designs (SR-71 for example) this is very hard to make happen (but the SR71 can stall it's engines before the wings stall due to AoA).
If you are faced with a stall, I would expect the first thing to do is to pitch down to reduce angle of attack then accellerate and pitch up to get out of it. T-tail designs are generally disfavored because the elevators can get blanked by the wings in a deep stall, but with the A330 this isn't an issue as it doesn't have this tail design.
I find it puzzling that a professional pilot would pitch up in response to a stall warning. Popular Mechanics is right to flag that is as difficult to understand.
Re: What really happened aboard Air France 447
#129Where does the captain go to take a nap? I was wondering how he didn't hear the stall sounds in order to immediately return.
Not sure about the AF configuration, but he would be resting either in a crew rest compartment fitted in the cargo hold [1], or alternatively in a reserved seat in business class.
Either way, no alarms are audible outside the cockpit.
[1] - http://www.airliners.net/aviation-forums/general_aviation/re...
Re: What really happened aboard Air France 447
#130Earlier quoted context omitted.
>at night, over an ocean, in a storm, with no visibility, in possibly significant turbulance Instead of finding out strategies on how to fly under these circumstances, why can't the plane change its course, if they anticipate the flying route to have these conditions. How about running some reconnaissance drones in the popular routes if they suspect a bad weather and want to check out. Or try out better weather monit…
Not changing course like almost all other flight that night was their first mistake.
I noticed that the article suggested their weather radar was incorrectly set up, so that might be their first mistake.