Originally Posted by
alvrb211
If you are familiar with the 737 rudder, you'll know that the design is very unusual. Secondly, it was proven to have been the cause of multiple fatal crashes. I'd say it was unusually poor! Even after the modification, it's a very unusual system which lacks redundancy!
The original 737 had a dual rudder PCU and yaw damper like the 727 but after tests showed it could be dispatched without the yaw damper, why have two? Thus.. only one for the 737.