Sully on AF 447

Since the passing of Walter Cronkite, it's possible that Sully is now the Most Trusted Man in America. So if Sully says the stick is a problem, what "defense" of it could Airbus make?
 
Becky said:
Since the passing of Walter Cronkite, it's possible that Sully is now the Most Trusted Man in America. So if Sully says the stick is a problem, what "defense" of it could Airbus make?
Click to expand...

Not this crap again. :mad2: Boeing versus Airbus debate usually argued by people with no experience on or actual knowledge of the differences. Even Sully said it might have made a difference.
 
Interesting the reporter translates "traditional airplane" to mean "Boeing" when in reality he literally meant 99% of the aviation fleet other than Airbus. I've never been in an airplane that the sticks/yokes didn't operate in unison.

So it's not really a Boeing vs. Airbus debate, but simply the wisdom of the control system implemented by Airbus.
 
From a few videos of A320 that I saw, it was very obvious that at least in the mode those guys were flying, sticks do not work like sticks on, say, F-16. They input a motion, not angle. Therefore pilots jerk the sticks a bit then return to neutral, while presumably the surfaces are deflected at the desired amount. To return surfaces to neutral one has to make opposing motions with the joystick. Sully was either unaware of it, or tried to oversimplify the way things work. And yes apparently there's no feedback in another stick in this system, as LD wrote just now.

I understand AF 447 was a different airplane and I have no idea if sticks switch to direct control in emergency.
 
zaitcev said:
From a few videos of A320 that I saw, it was very obvious that at least in the mode those guys were flying, sticks do not work like sticks on, say, F-16. They input a motion, not angle. Therefore pilots jerk the sticks a bit then return to neutral, while presumably the surfaces are deflected at the desired amount. To return surfaces to neutral one has to make opposing motions with the joystick. Sully was either unaware of it, or tried to oversimplify the way things work. And yes apparently there's no feedback in another stick in this system, as LD wrote just now.

I understand AF 447 was a different airplane and I have no idea if sticks switch to direct control in emergency.
Click to expand...

AF447 was an A330, cockpit is almost identical to the A320.
 
In fact, I had a nice discussion with Sully (and John King) on this subject last summer. Somewhere there's a picture that the A&S magazine photographer took of this that I want a copy of.
 
zaitcev said:
From a few videos of A320 that I saw, it was very obvious that at least in the mode those guys were flying, sticks do not work like sticks on, say, F-16. They input a motion, not angle. Therefore pilots jerk the sticks a bit then return to neutral, while presumably the surfaces are deflected at the desired amount. To return surfaces to neutral one has to make opposing motions with the joystick. Sully was either unaware of it, or tried to oversimplify the way things work. And yes apparently there's no feedback in another stick in this system, as LD wrote just now.

I understand AF 447 was a different airplane and I have no idea if sticks switch to direct control in emergency.
Click to expand...


That's not how it works. The sidestick controls a G-loading in pitch and roll rate in roll. It's pitch and bank neutral. If you want to pitch up just a little, you'll bump the sidestick up to increase the g-loading via pitch then return to neutral when you have the desired pitch attitude. Same with roll, basically. You don't move the flight control surfaces directly. You command the plane what you it to do and it will do it. Just like AF447, that plane did exactly what they told it to do.
 
Last edited:
Apparently they completely forgot half of their instrument training, ie cross-referencing their primary to supporting instruments. IFR101. This is where I slightly differ on what Sully said. We can blame the pilots. It's been proven that if you communicate as a team and use ALL the instruments correctly, these planes can fly without crashing. Sure, I personally like the feed-back of the conventional design, but every other flight in an Airbus has proven it works just fine.
 
Last edited:
Actually, there does seem to be a reason the co-pilot was holding full back stick that Sully seems unaware of:

http://aviationsafetyconsultant.com/pilot-error-in-the-air-france-447-accident/

"When Airbus developed it’s fly-by-wire control system for the A-320 and subsequent aircraft, it was often stated the Airbus system was “just like other aircraft, but better.” Part of the “better” was that Airbus designed protection limits in the system such as high angle of attack (AOA) limits which prevented a stall. The advantages of this feature were extolled in technical reports like SAE 861801.

Dual page magazine adds stated “Taking the danger out of windshear. . . . The pilot then simply pulls back on the side-stick, and the aircraft automatically corrects itself to achieve the maximum lift needed to fly out of danger.” (Newsweek, 9/14/87). Pilots were trained to use this by selecting TOGA (take off/go around) thrust and holding back stick input to achieve what was considered to be maximum performance—not really though because at the limiting AOA an aircraft is far up the back side of the drag curve which limits flight path performance as well as not allowing any extra lift force to be generated to redirect the flight path if it happens to be going in the wrong direction, i.e., down. One feature was that the system would automatically select TOGA.

Certain failures, such as loss of airspeed information, can cause the Airbus flight control system to revert from Normal Law to Alternate Law in which AOA limit and protection is lost. That the PF (pilot flying) of Air France flight 447 thought he was reacting as he should by selecting TOGA and holding full back stick, despite system reversion to Alternate Law, is clear by his statement less than 1 minute before the crash, ”But I’ve been at maxi nose-up for a while.”"
 
alfadog said:
Actually, there does seem to be a reason the co-pilot was holding full back stick that Sully seems unaware of:

http://aviationsafetyconsultant.com/pilot-error-in-the-air-france-447-accident/

"When Airbus developed it’s fly-by-wire control system for the A-320 and subsequent aircraft, it was often stated the Airbus system was “just like other aircraft, but better.” Part of the “better” was that Airbus designed protection limits in the system such as high angle of attack (AOA) limits which prevented a stall. The advantages of this feature were extolled in technical reports like SAE 861801.

Dual page magazine adds stated “Taking the danger out of windshear. . . . The pilot then simply pulls back on the side-stick, and the aircraft automatically corrects itself to achieve the maximum lift needed to fly out of danger.” (Newsweek, 9/14/87). Pilots were trained to use this by selecting TOGA (take off/go around) thrust and holding back stick input to achieve what was considered to be maximum performance—not really though because at the limiting AOA an aircraft is far up the back side of the drag curve which limits flight path performance as well as not allowing any extra lift force to be generated to redirect the flight path if it happens to be going in the wrong direction, i.e., down. One feature was that the system would automatically select TOGA.

Certain failures, such as loss of airspeed information, can cause the Airbus flight control system to revert from Normal Law to Alternate Law in which AOA limit and protection is lost. That the PF (pilot flying) of Air France flight 447 thought he was reacting as he should by selecting TOGA and holding full back stick, despite system reversion to Alternate Law, is clear by his statement less than 1 minute before the crash, ”But I’ve been at maxi nose-up for a while.”"
Click to expand...
But you'd think any sane pilot would eventually conclude that something wasn't working as expected when the stall warning keeps going off and the airplane becomes unstable in roll. Even if he failed to recognize that the system wasn't in normal law (you'd think they'd be trained to notice that) the behavior of the airplane should have suggested that some other control input might be better.
 
gismo said:
But you'd think any sane pilot would eventually conclude that something wasn't working as expected when the stall warning keeps going off and the airplane becomes unstable in roll. Even if he failed to recognize that the system wasn't in normal law (you'd think they'd be trained to notice that) the behavior of the airplane should have suggested that some other control input might be better.
Click to expand...

The PF was also a glider pilot so I am willing to assume that he knew how to fly. I am wondering if we are seeing a failure in training, i.e. the pilots are taught that the airplane is a "better pilot" and smarter than they are. Before I read this I was always down on the PF almost exclusively but now not so much. Still down on the crew as a whole but sounds like the PF was doing something he had been trained to do.
 
As I have observed elsewhere, Airbus designs to protect the airplane from the pilot and Boeing designs to protect the pilot from the airplane.

Cheers
 
I guess experience and training shows. Would you lose 30,000 feet doing what you're doing without thinking about trying something else?
 
What the stick does for you in different control laws varies dramatically. The fundamental mistake here was that the PF did not understand which control law he was operating within.
 
bqmassey said:
What the stick does for you in different control laws varies dramatically. The fundamental mistake here was that the PF did not understand which control law he was operating within.
Click to expand...

The fundamental problem, it seems to me, is training pilots to let the airplane control the flight (i.e., TOGA and pull all the way back, let the AOA limiter get you max performance), rather than teaching them to control the plane and let the airplane system protections be a safety net to a dumb mistake.
 
I was able to sit in on breifing on this accident from an Airbus IP who is involved in the litigation.

One thing he mentioned was the cacophony of warnings, messages, lights, sounds, and voices that the airplane presented to the pilots. He felt this could be very confusing in such a situation.

The other was that Airbus offers an option not used by Air France called a 'back up speed scale' on the backup attitude instrument. This turns the backup display into an AOA indictor. The Airbus IP thought this option might have helped the accident crew.
 
JimNtexas said:
I was able to sit in on breifing on this accident from an Airbus IP who is involved in the litigation.

One thing he mentioned was the cacophony of warnings, messages, lights, sounds, and voices that the airplane presented to the pilots. He felt this could be very confusing in such a situation.

The other was that Airbus offers an option not used by Air France called a 'back up speed scale' on the backup attitude instrument. This turns the backup display into an AOA indictor. The Airbus IP thought this option might have helped the accident crew.
Click to expand...

The BUSS is displayed on the PFD in place of the airspeed tape, not on the ISIS (integrated standby instrument system).

I'm surprised it's not on the AF planes, all of our 319's and 320's have it.
 
You must log in or register to reply here.
Back
Top