Originally Posted by
Lead Balloon
Ah, but you’re presuming that the rudder trim was physically at FSD and the indication system said so as each of the aircraft lined up.
I have yet to be convinced that there is no possibility of a latent defect in the rudder trim system in these aircraft. In each case there has yet to be any first-hand evidence-based explanation as to how and when the rudder trim came to be at FSD before take-off. I have spent many thousands of hours over many years tracking down weird faults in complex flying machinery, which faults were almost invariably easily dismissed as pilot error but turned out not to be.
I simply have a method to ensure takeoff with the rudder trim selector at the proper indication. This will cover 99.999999%(yes that is a guess) of situations where the rudder trim system is working properly. My recommendation is for and works for aircraft which are serviceable. For the other extremely tiny amount of situations where there is an actual malfunction of the system, this method will not guarantee that the trim system is properly set, in a similar manner that an indication fault for the flaps will also bypass this method. However, a proper pre-flight check in many of those situations(and quite possibly this accident) will lead to discovery of the faulty system.
I suspect that most of the other crashes mentioned in the report would have been avoided if a final check had been performed but if there was one of those extremely rare malfunctions, it may not have help and could even make things worse.