THS Jackscrew design

[DozyWannabe]

In the wake of Alaska 261 there were cross-type and cross-manufacturer inspections and ADs mandated. No implementation (of which each manufacturer's was slightly different) was entirely free of problems in terms of maintenance or design:

Airbus : FAA mandates near-term A320 stabiliser inspections

Boeing : FAA calls for heightened 737 trim actuator vigilance

Here's a contemporary article on the subject:

Aviation Today :: Jackscrew Jugular Can Be Fixed