ITman
So bench testing is superior to flight testing and associated ground handling..?
Often it is. In flight tests the testing is constrained to nominal (normal) usage of the systems they can be pushed to the edge of normal but cannot be exception tested.
In ground testing with all the aircraft systems running - Boeing has test bays with all the production level systems connected but in labs on the ground - the test script can include failures of all types in any areas required . A multi-rotation flight series can be accurately emulated for a baseline then failures of various systems added to more repeated runs. Some of these failures may be impossible to trigger in a flying aircraft or 'catastophic' so dangerous to implement in an airborne aircraft. Even pressure and temperature changes cannot be run in a controlled script in a live aircraft.
Overall the more controlled certification level testing is far more efficient and complete in a ground test than in an unpredictable and limited air test.