John Derry aircraft exceeding its design limits
The DH110 design had one major flaw in the straight tailplane which would suffer from compressability before the mainplane - a bit of a disaster for stability at high Mach numbers. In service, the MNO of the Sea Vixen was subsonic. Dan Griffiths, while displaying the last airworthy Sea Vixen had some thoughts on the matter.
https://vintageaviationecho.com/flying-the-sea-vixen/