PPRuNe Forums - View Single Post - AF 447 Search to resume
View Single Post
Old 30th May 2010, 14:01
  #1284 (permalink)  
bearfoil
Guest
 
Posts: n/a
henra

The trailing edges are in no way pristine.
They (corners) have failed down, the entire trailing edge has folded backward (from overloading), and the leading edge has failed from the middle (as a result of the hinges popping loose. At this point, all the airstream needs is a "peek" underneath, and the game is over The airflow is directed under the popped leading eedge, and fills the unprotected bottom surface with extremely energetic air. Meanwhile, the spill from the trailing edge has gotten mixed with other symmetrical spill and creates a local tornado of randomly blended vortices.

It is this folding of the panel back that precipitates failure, as it puts an enormous load on the center hinges, those in front of the actuator. The next stage is a rocking back and forth of the panel alternately loading either trailing corner. It is this undesigned for load that attacks the unengineered for weaknesses of the a/c that push the otherwise capable airframe into uncharted regions. Using an additional actuator might be one approach; bear in mind, this a/c is capable for all use as intended, it is not some exotic fighter that carries a single occupant. Aviation has categories and the 330 is a well made machine.

I think it is clear that the spoilers were deployed, and that some air loads were beyond design. As for the Flaps, they are inordinately robust as designed, but they were not meant to be a stand-in Hull for a water landing.I do think they separated, however, and if the Spoilers did not shear off in flight, they may well have been taken off with the Trailing edge of the wings.

takata

bonjour. I think no one is bullying anyone. A different point of view is not aggression. ACARS had one message left to send, as we know, there is that delay in transmission. You speak of loss of Lateral control, but all that has been shown is Lateral failure of the VS mounts. When the mounts broke and when or if the VS was lost in flight has not been established. Just as the spoilers were deployed as a result of some effort to gain stable flight, (an opinion), the VS may have stayed on.

It also may have separated. I have a theory as to what occurred, and it is based on what is publicly known.

I do know what happens to control surfaces when their mounts are broken. After mount failure, there is a lack of direct response, and depending on circumstances, control is compromised in vibration, loss of rigidity, and ever increasing play. It is this play that needs to be handled with great care. Just as more control is desired, there is degraded performance, and the temptation is to regain the control provided by increasing input. It is a cycle that has befallen uncounted aircraft

au demain,

bear

Last edited by bearfoil; 30th May 2010 at 14:35. Reason: to address takata