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Air France 447 - interesting article

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ORD Don:



             
                   An interesting article from Popular Mechanics....


                   http://www.popularmechanics.com/technology/aviation/crashes/what-really-happened-aboard-air-france-447-6611877-2

       

notaperfectpilot:
very interesting...I still cannot understand how you can have the stick all the way back for about 2 min. and still not realize that you are in a stall and dropping like a rock.

joeyb747:

--- Quote from: notaperfectpilot on December 09, 2011, 12:08:12 PM ---very interesting...I still cannot understand how you can have the stick all the way back for about 2 min. and still not realize that you are in a stall and dropping like a rock.

--- End quote ---

Like the "Unsinkable" Titanic, too much faith was placed in what the vehicle "can't" do...

From the article:

""You can't stall the airplane in normal law," says Godfrey Camilleri, a flight instructor who teaches Airbus 330 systems to US Airways pilots.

But once the computer lost its airspeed data, it disconnected the autopilot and switched from "normal law" to "alternate law," a regime with far fewer restrictions on what a pilot can do. "Once you're in alternate law, you can stall the airplane," Camilleri says."

"You can't stall the airplane in normal law...", meaning you can pull the stick all the way back and the airplane will pitch to a limit point and no further, it will not go to far and stall the wings...in NORMAL LAW. ALTERNATE LAW however, removes most of these such protections.

Check this out:

Normal Law, Protections, section:

"High Angle of Attack Protection (alpha):

*When alpha exceeds alpha prot, elevator control switches to alpha protection mode in which angle of attack is proportional to sidestick deflection.
*Alpha max will not be exceeded even if the pilot applies full aft deflection"

Alternate Law, Protections, section:

"*The airplane CAN be stalled in Alternate Law."

From:

http://www.airbusdriver.net/airbus_fltlaws.htm

This page is a great comparison of NORMAL LAW and ALTERNATE LAW.

notaperfectpilot:
so, this guy had it engraved is his mind that with the fly-by-wire system working properly, he could NOT stall the airplane NO MATTER HOW FAR HE PULLED BACK ON THE STICK because the airplanes computer WOULD NOT let it stall, correct? In this case, the fly-by-wire system was NOT working the way it normally would because of the airspeed malfunctions, correct? So, since he did NOT know that the system was not operating the way it usually did, he thought it was impossible the stall the airplane . So, if I understand everything right, the FO did the RIGHT thing with the information that he had. Correct me if I am wrong.   

ORD Don:





            I just realized that the link that I inserted for this thread is for Page 2 of the article. 

            The link below directs you to the beginning of the article.   Sorry........ :?


            http://www.popularmechanics.com/technology/aviation/crashes/what-really-happened-aboard-air-france-447-6611877

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