> 1985 the dedliest single aircraft accident was due to dutch roll. Japan Airlines Boeing 747SR.

This kind of buries the lede, right? A bad repair caused an explosion that blew off most of the vertical stabilizer (ie, the tail). The dutch roll was part of the series of unfortunate events that followed.

This is extremely disingenuous. A dutch roll if identified and corrected is not structurally dangerous to an aircraft but it typically signifies something wrong with the control surfaces which is a larger issue. In the majority of the cases, it's the yaw damper that's a problem (my suspicion in the 737 case).

JAL 123 crashed because hydraulic pressure on all 4 hydraulic lines and 90% of the vertical stabilizer and 100% of the rudder were lost due to an explosive decompression of the aft pressure bulkhead. Dutch rolls ensued because of the loss of lateral direction control.

The KC-135 crashed because the rudder power control unit on the rudder was faulty and the pilots failed to identify the problem. They then used alternating rudder inputs to recover which caused the structural limits of the vertical stabilizer to be exceeded its structural limits and separate (along with the rest of the tail).

The Air Transat flight (961) had the entire rudder separate from the aircraft most likely due to stress fractures. This caused the aircraft to have extremely limited lateral directional control which caused the dutch rolls.

Of those three examples, only the KC-135 was caused by the dutch roll. The other two were caused by structural failures, the dutch roll was incidental.