747 Downwind :
Indeed, if any a/c is potentially unsafe it must be the A320.. numerous incidents have occurred yet there has been no diagnosis.
There's been a *lot* of diagnosis, and a complete overhaul of the human-computer interface involved.
The issue was one of mode confusion (pilots misinterpreting what mode the flight-management computer was in) - and there were a few 'schoolboy' errors in the initial design (push/pull multi-function knobs are considered a big no-no in that kind of environment). These have since been resolved.
Most aircraft with new aspects to their design are prone to teething problems, some serious (The Comet being the most famous example, but the 727 and second-generation Airbus being others), but all evolved to become perfectly safe designs, once the initial concerns were weathered and the bugs ironed out.
Remember though, that Boeing strenuously denied the existence of rudder hardovers in the 73 caused by the PCU until presented with irrefutable evidence.