What was found
FLT NR 5392 - BOS - SMOKE APPEARED IN THE CABIN ON APPROACH TO BOS WITH THE ENGINE AND AIRFOIL ANTI-ICE ON. THE SAME PROBLEM HAD OCCURRED ON THE PREVIOUS FLIGHT. THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND A RUPTURED DIAPHRAGM IN THE RT WATER SEPARATOR TEMPERATURE CONTROL VALVE. THE CONTROL VALVE WAS REMOVED AND REPLACED. IN ADDITION, THE RT ACM WAS REPLACED AS A PRECAUTIONARY MEASURE, AND THE RT COALESCER BAG WAS REPLACED. A FUNCTIONAL CHECK WAS PERFORMED AND NO LEAKAGE WAS PRESENT IN THE RT PACK SYSTEM. BURNOUT PROCEDURES WERE COMPLETED IAW MM 21-20-02, PAGE 209, PARAGRPAH C AND NO FURTHER SMOKE OR ODORS WERE PRESENT. (Z)