IIRC, there were some control law changes made after the A320 Mulhouse crash as the pilots could not override in time what the plane was trying to do (still land when the pilot had commanded a go-around). A couple of years later IIRC, one in service in India crashed for something similar and I believe the airline or govt suspended A320 operations until some things were changed.

However, I do recall the 330 test flight crash in the 90's was not put down to the a/c.

And we are now 17 years on from the 320 EIS and about 10 from the 330 and things have moved on another leap - but the accuracy of the design models still must be verifed with real data at the extremes of the envelope for certification.

The most impressive one IMO is the rejected take-off at full take-off weight - I believe this is done close to V1 speed - (can an expert comment here?). The a/c must stop safely and the brakes must not catch fire. There was a film of the 777 tests of this and IIRC the tires all burst as the plugs melted.

Makes you thankful when the things are screaming down the runway that the whole envelope has actually been tested for all eventualities!!. Things must have got much better as with the 777/330/340 generation I don't believe been an in-service pax fatality in over 10 years of ops. Long may it continue.