Originally Posted by
G0ULI
Standard aviation design notes suggest that the rudder be capable of resisting full aileron deflection on single engine aircraft or an outboard engine failure with other engines developing full takeoff power on multiengine aircraft at speeds 1.2 times the stall speed.
Either the Electra design was flawed in that respect, or the ailerons were or became deflected and held at considerably more than three degrees.
To counter the right wing down command, the rudder needs to move the nose left. In level flight this will roll the sim Electra over.
I've said that the problem was they were already in a bank when the problem was noticed. Below the speed at which a plane can do knife-edge flying, for any given speed there is some bank angle which is the maximum bank that the rudder can counter. The rudder needs to move the nose left, which in a bank has a vertical component. The sim tells me at about 160 knots the maximum right bank is near 60 degrees, meaning beyond that angle the rudder can't lift/left the nose. At that angle the plane can fly indefinitely. And when near that angle the rudder's authority is severely degraded.
I think they were calling for left rudder and the plane was balanced, if you will, near the peak of that curve. A little higher bank and the rudder would have lost all effect, they would have gone down much faster; a little lower and they would have recovered no problem. They were in the flatter part of the response curve, and it took some time for the nose to lift. Once it started to lift, like rolling down a slope, it gained speed. So I think they were rolling fairly quickly left when the right wing hit the embankment.
It wasn't an issue of bad design, in my [nonpilot] opinion, but bad luck that they didn't know of the problem until they were too far into the zone where the rudder authority is degraded. We've discussed this here previously, and I'm including it in my next release.