PPRuNe Forums - View Single Post - AF447 final crew conversation - Thread No. 1
Old 11th Feb 2012, 21:11
  #1300 (permalink)  
Machinbird
 
Join Date: Jul 2009
Location: Not far from a big Lake
Age: 82
Posts: 1,454
Likes: 0
Received 0 Likes on 0 Posts
Quote:Machinbird
Another weakness of the design. A large transport aircraft should need two hands to hold it in a stall, not a crooked pinky finger.
Originally Posted by Iceman
That is where you are totally wrong. Tried it in the sim and it takes great effort on the sidestick and and effort that has to be maintained!!
Quote:
but it loses natural speed stability and requires increased attentiveness/awareness in manual flight-or an automatic speed control system.

Originally Posted by Iceman
Wrong again it makes it more stable.
Iceman.
My first impression was that you had done your sim evaluation in a Boeing type sim, but I see you list yourself as a 'Bus pilot, seat 0A, so will give you the benefit of the doubt.

It takes effort to hold the stick back in the 'Bus to get the nose up, but once it is there sufficiently high, and the trim runs up, it takes little effort as Confiture describes.

Do not confuse the ease of holding an airspeed in your 'Bus due to the attitude stability with possession of natural speed stability. Your 'Bus is a C* aircraft and is attitude stable, not speed stable. That got AF447 into trouble in Alt 2 law. Once the nose got pointed well up into the sky that aircraft was going to decelerate, even with no further stick input, and the trim was going to run up to the limits in blind obedience-no protections.

If you don't believe me, try flying the 'Bus sim at 12-15 degrees nose up in Alt2 law at altitude. Once there, it won't make a difference what you do with the power. As long as you keep your hands off the pitch input, that aircraft will decel to the stall and keep on decelerating, and the trim will run as far up as it can.
Machinbird is offline