Originally Posted by
Casper
Has it been officially proved (and beyond doubt) that rudder hardover was a factor in Colorado Springs and Pittsburgh?
As far as I know, the answer to your question is "no." However, the circumstances do point, quite heavily, toward rudder involvement.
The significant point, however, does not necessarily stop at understanding the rudder implications. In both of these cases, the crew was at a relatively slow airspeed and the indications were that they tried to slow even further. There is a phenomenon called "cross-over speed" that comes into play in circumstances such as these. This is where, at a given speed, the rudder and the ailerons are equally effective in controlling the roll of the airplane. Below that speed, the rudder becomes even more effective in that control. Above that speed, the ailerons become more effective. In both of these cases, there is a reasonable likelihood that, had the crew accelerated to something above that "cross-over" speed, they would have been able to recover, even WITH the existing rudder problem thought to exist.