What was found
(CAN) WHILE IN FLIGHT,TAIL ROTOR TIP CLOSURE FROM BLADE S/N A-9612 DEPARTED BLADE. ENSUING, EXTREME VIBRATION, CAUSED PILOT TO LAND IMMEDIATELY, WITHOUT FURTHER DAMAGE TO A/C. INSPECTION OF T/R SHOWED TIP CLOSURE OF BLADE S/N A-9612 TO BE GONE IN ITS ENTIRETY, LEAVING HONEYCOMB INNER STRUCTURE TOTALLY EXPOSED. BOTH BLADES WERE REMOVED FROM ASSY AND WERE FORWARDED TO TSB (PICKWICK). T/R HUB ASSY IS BEING HELD IN QUARANTINE AT CONAIR HELICOPTERS TILL FURTHER NOTICE. AS AN ADDITIONAL PRECAUTION 90 DEGREES T/R GEARBOX HAS BEEN REMOVED FOR OVERHAUL. A/C INSP FOR FURTHER DAMAGE - NONE FOUND. REPLACED 90 DEGREES TAIL ROTOR GEARBOX, TAIL ROTOR ASSY AND PITCH CHANGE ASSY INSTA