Originally Posted by
alanh
From 1967-1991 (24 years!), there were no 737 crashes related to PCU rudder valves. Therefore, it's impossible for it to happen, correct?
Of course, UA 585 happened in 1991 and US 427 in 1994, and it turns out that there was a latent defect that under certain rare conditions, cause a rudder hardover that would make the aircraft impossible to keep in the air.
So, should it have been fixed, or is that simply too rare a circumstance to do anything about?
This is not analogous to the issue of PED's. There is clear evidence that can be lab tested and investigated regarding the valve, and the pilot training associated with how the airplane is flown. With PED's we have literally had 100's of millions of flights with NO EVIDENCE of any impact. None. There are far more data points regarding the safe operation of PED's on board commercial airliners than there is evidence of crashes for any other reason.