I was recently on a SWA flight aboard a 737-800, and looking at the
large winglet that the 737-800 sports (for lift enhancement, drag
reduction), it occured to me that perhaps the recent 737-800 that went
down in Brazil after colliding with an Embraer jet may have had one of
its winglets sliced off. The reports that I have read state that the
737-800 spiraled out of control after the collision, which I could
envision happening if the lift/drag of the main wings had a large
amount of asymmetry due to the loss of a winglet. The Embraer lost a
portion of its wing, so if the two planes clipped wings, odds are the
Embraer hit the 10 feet tall winglet rather than the wing itself since
they are both in level flight.

This is pure speculation, but it will be interesting to see if the
final report from Brazil indicates that this is what occured.

Dean