What was found
(CAN) DURING FIRE FIGHTING OPERATIONS WATERDROP , HYDRAULIC FAILURE OCCURRED. AIRCRAFT LANDED AFTER EMERGENCY LANDING GEAR EXTENSION WITH BOMB DOORS OPEN AND WAS TOWED OFF RUNWAY. THIS IS THE SECOND FAILURE ON THE SAME AIRCRAFT IN THE SAME POSITION WE HAVE HAD THIS SUMMER FROM CHECK VALVE FAILURE. NEW STAINLESS VALVES HAVE BEEN ORDERED TO COMPLY WITH SUGGESTED CANADAIR SERVICE BULLETIN BUT HAVE NOT ARRIVED. WE HAD TO USE THE OLD STYLE ALUMINUM CHECKVALVE WHEN IT WAS REPLACED EARLIER IN THE SPRING. SEE REFERENCE PREVIOUS SDR #20060427007 DATED MAY 12, 2006. (TC# 20060704020)