TWO MECHANICS REPORT THE AFT LAV VACUUM TOILET BLOWER MOTOR WAS IMPROPERLY DEACTIVATED ON A B737-800. CABIN MAINT PROCEDURES MANUAL SHOULD STATE TO PULL THE VACUUM WASTE BLOWER CIRCUIT BREAKER INSIDE P-91 PANEL.
Synopsis
TWO MECHANICS REPORT THE AFT LAV VACUUM TOILET BLOWER MOTOR WAS IMPROPERLY DEACTIVATED ON A B737-800. CABIN MAINT PROCEDURES MANUAL SHOULD STATE TO PULL THE VACUUM WASTE BLOWER CIRCUIT BREAKER INSIDE P-91 PANEL.
Narrative
ACFT X HAD A PIREP OF NOISE FROM AFT LAVATORIES. THIS MAINT PERSON FOUND THE LAVATORY BLOWER MOTOR FAULTED. THIS WAS THEN PUT ON PLACARD IN ACCORDANCE WITH MEL. THE PROC TO PLACARD THIS INOP; WAS TO PULL AND COLLAR APPLICABLE CIRCUIT BREAKERS OF THE INOPERATIVE BLOWER MOTORS. NO LOCATION IS GIVEN TO ACCOMPLISH THIS PROC. WHILE TROUBLESHOOTING THE PROB; OF LAVATORY TOILETS NOT FLUSHING; IT WAS FOUND THAT THE VACUUM WASTE CTL CIRCUIT BREAKER WAS PULLED AND COLLARED. THE CIRCUIT BREAKERS FOR THE VACUUM WASTE BLOWER IS LOCATED BEHIND THE P91 PANEL. THIS WAS ALSO PULLED AND COLLARED. WHILE REFING WDM AND SSM; IT WAS FOUND THAT IF THE CTL BREAKER IS PULLED; THIS WILL INOP ALL 3 LAVATORY TOILETS TO NOT FLUSH. THE REASON FOR ACFT X TO MAKE IT A 'FIX BEFORE DEP' WAS DUE TO THE LAVATORIES NOT FLUSHING. THE MEL SHOULD HAVE THE PROC STATE THAT THE VACUUM WASTE BLOWER FOR THE B737; CIRCUIT BREAKER GIVE A LOCATION; AND NUMBER. REF SSM. VACUUM TOILET BLOWER MOTOR WAS IMPROPERLY DEACTIVATED. NOT ENOUGH INFO WAS PROVIDED WHEN INOP THE BLOWERS. THE WRONG CIRCUIT BREAKER WAS PULLED TO INOP THE WASTE VACUUM BLOWER. SUPPLEMENTAL INFO FROM ACN 800128: THE MEL IS NOT SPECIFIC AS TO THE BREAKERS THAT NEED TO BE PULLED. REF WIRING DIAGRAM; VACUUM WASTE CTL C1388 IS ON P-91 PANEL LOCATION C-11 (BREAKER PULLED) THIS IS THE OBVIOUS BREAKER TO PULL AND VACUUM WASTE BLOWER C1389 LOCATION. F2 IS LOCATED INSIDE P-91 PANEL (BREAKER PULLED). BOTH BREAKERS WERE PULLED DUE TO THE REF IS NOT SPECIFIC AS TO THE LOCATION OF THE BREAKERS AND DOES NOT STATE HOW MANY BREAKERS TO PULL. THE MEL IS NOT ACFT SPECIFIC. IT IS FOR B737 AND B767 AND SHOULD STATE PULL VACUUM WASTE BLOWER CIRCUIT BREAKER LOCATED INSIDE P-91 PANEL; LOCATION F2. NOT VACUUM WASTE CTL ON P-91 PANEL. THIS SHOULD BE MADE AN MEL WITH MAINT PROCS AND STATE CIRCUIT BREAKERS AND LOCATIONS. THERE ARE NO SPECIFIC NUMBERS FOR CIRCUIT BREAKERS TO BE PULLED IN THE MEL. THE OBVIOUS CIRCUIT BREAKER IS THE VACUUM WASTE CTL ON THE P-91 PANEL.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.