What's with the warning from the Captain, " Our survival depends on your cooperation", what can pax do apart from sitting down and belting up, and it appears the capt put maint support ahead of the safety of the pax with his decision to return to Perth, a 90 min flight on one good engine , with the other vibrating madly, the stress on everything from the turbine shafts, pylons, wing structure and fuselage must have been considerable.