What really happened aboard Air France 447

It's interesting that First Officer Bonin is able to doom the plane by continuing to hold back on his joystick, even when that action isn't having positive results. Had the other first officer pushed his joystick forward, would the plane begin to dive? I assume that one joystick has precedence over the other...

It seems dangerous to have two joysticks, both capable of controlling the plane, that have no physical or simulated physical link. It means that one pilot could be attempting to control the plane and his actions will have no effect whatsoever if the other seat is panicking (as in this case).

Anyone have any insight into this?

Re: What really happened aboard Air France 447

#6

Post by citricsquid » Thu, Dec 08, 2011, 3:32 AM UTC

The lack of reaction to "Stall!" implies one of two things; either it was broken and the sound didn't play or the complete lack of understanding about what the word "Stall" meant with the pilots. Has either of these been proposed and discussed? The author of this piece doesn't seem to touch on why they ignore "Stall!", unless it's been confirmed the sound had been heard (on the recording maybe?) and they did indeed understand what "Stall" meant as it's "standard" pilot language?

Why would they ignore it...

Re: What really happened aboard Air France 447

#7

Post by jeffbarr » Thu, Dec 08, 2011, 3:32 AM UTC

huntero wrote: post #5

It's interesting that First Officer Bonin is able to doom the plane by continuing to hold back on his joystick, even when that action isn't having positive results. Had the other first officer pushed his joystick forward, would the plane begin to dive? I assume that one joystick has precedence over the other... It seems dangerous to have two joysticks, both capable of controlling the plane, that have no physical or s…

According to the article, the input from the two joysticks is averaged.

Re: What really happened aboard Air France 447

#8

Post by yew » Thu, Dec 08, 2011, 3:34 AM UTC

citricsquid wrote: post #6

The lack of reaction to "Stall!" implies one of two things; either it was broken and the sound didn't play or the complete lack of understanding about what the word "Stall" meant with the pilots. Has either of these been proposed and discussed? The author of this piece doesn't seem to touch on why they ignore "Stall!", unless it's been confirmed the sound had been heard (on the recording maybe?) and they did indeed u…

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.

Re: What really happened aboard Air France 447

#9

Post by kmort » Thu, Dec 08, 2011, 3:37 AM UTC

citricsquid wrote: post #6

The lack of reaction to "Stall!" implies one of two things; either it was broken and the sound didn't play or the complete lack of understanding about what the word "Stall" meant with the pilots. Has either of these been proposed and discussed? The author of this piece doesn't seem to touch on why they ignore "Stall!", unless it's been confirmed the sound had been heard (on the recording maybe?) and they did indeed u…

The author did touch on it:

"According to Camilleri, not one of US Airway's 17 Airbus 330s has ever been in alternate law. Therefore, Bonin may have assumed that the stall warning was spurious because he didn't realize that the plane could remove its own restrictions against stalling and, indeed, had done so."

Re: What really happened aboard Air France 447

#10

Post by zwadia » Thu, Dec 08, 2011, 3:39 AM UTC

Can anyone explain the virtues of asynchronous and dual input modes? Why would it average the inputs?

Why would it not give the co-pilot feedback? Is it because instinctual resistance to yoke feedback would result in imprecise inputs during manual maneuvers?