PPRuNe Forums - View Single Post - Pilot Commands TOGA; A320 lands anyway
View Single Post
Old 9th Jun 2001, 13:07
  #92 (permalink)  
Frederic
Guest
 
Posts: n/a
Cool

bunyip,
"The Boeing product takes this into account and if I need to, I can put that airplane wherever I want, whenever I want. " ?
Although I appreciate your view on the subject seems to be more openminded than most other's on this string, I have to disagree with the above statement. You cannot put the any aircraft wherever you want whenever you want. Aircraft have aerodynamic limitations. Maximum angle of attack will give you maximum lift coefficient on any aircraft FBW or not. So the manoeverabimity of an aircraft is limited by the amount of lift it can produce.Boeing aircraft will allow you to pull the aircraft to a slightly higher angle of attack. But what is the use? Higher than max alpha will give you a lower lift coefficient, and so LESS manoeverability. The AI FBW system is designed to give you maximum lift coefficient whit full back stick or max G, whatever is higher. You do need to allow the system to temporarily overshoot it's limits and -MAYBE- that if where AI didn't allow enough "play"?
Where I think most critics of FBW are wrong is that they don't differentiate between design faults and inherent defficienties. In this incident there -probably!- whas a design fault that prevented the aircraft from achieving maximum angle of attack. So there is one element in a much bigger system that failed to work correctly instead of it being inherently defficient. I think every airliner should have angle of attack protection. Please understand that this does not limit the authority of the pilot. On the contrary, it concistently gives the pilot maximum manoeverability right when he needs it by simply applying full aft stick. That is provided it works well. In this case it didn't. So there is a fault in the system. And apparently AI is correcting it. As usual in aviation you immediatly hear about when things go wrong. But how many times did AI's FBW save the day?