use2flyboeing,
Yes, there have been rudder modifications already installed on the 737, and there have been a number of incidents with the modified rudder!
Let Mr. Rayfield, the final controller handling United 585, tell you what actually happened by his sworn statements, in the ATC Chairman's Factual Report, (which was never included in the NTSB's final report!!!) Mr. Rayfield stated that United 585 pitched over into a vertical dive, it never rolled, it went straight in!!!
Jim Hall, the NTSB Chairman at the time, said that the B727's wake turbulence never affected USAir 427, ignoring completely the thumps and the clicks of the stabilizer trim wheels, recorded on the CVR, as they reacted to the wind shear in the B727's wake turbulence!
The USAir 427 Medical Exaiminer stated that both pilots' left legs were fully extended at ground impact and both left rudder pedals were completely sheared off their supporting structure. The aircraft impacted the ground in a steep left bank!!!