Originally Posted by
Centaurus
why didn't CASA airworthiness notice this when the Bristell was approved for student training?
That doesn't happen. However, CASA knew that the type was used for incipient spin training per their Part 61 requirements yet was not approved for intentional spins and did nought about it.
Originally Posted by
Centaurus
If, as claimed in the report, some instructors said the Bristell would drop a wing in the stall, then could this be an airworthiness issue? After all, there are certification rules that govern wing drop tolerances.
Not really, the requirement is for the test pilot to be able to prevent the wing drop exceeding specified amounts - that is test pilot, not just an instructor let alone a student pilot.