A B737-300 flight crew has postflt concerns about the MEL that was exercised upon a leading edge sla...

Attributes
ACN	513075
Time
Date	200105
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : hou.airport
State Reference	TX
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	A300
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance ground : parked
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 240 flight time total : 5000 flight time type : 1500
ASRS Report	513075
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 246 flight time total : 12000 flight time type : 9000
ASRS Report	512652
Events
Anomaly	maintenance problem : improper maintenance maintenance problem : improper documentation maintenance problem : non compliance with mel non adherence : far
Independent Detector	aircraft equipment other aircraft equipment : master caution other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Consequence	other other
Factors
Maintenance	contributing factor : schedule pressure contributing factor : engineering procedure performance deficiency : non compliance with legal requirements performance deficiency : repair performance deficiency : testing performance deficiency : fault isolation performance deficiency : inspection performance deficiency : logbook entry
Supplementary
Problem Areas	Company Flight Crew Human Performance Maintenance Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

Check of master caution inbound to hou indicated a single channel failure of the automatic slat system. Maintenance was advised and met aircraft at the gate. They determined that a circuit breaker behind the captain's seat (exact breaker unknown) was popping and causing the indication. Aircraft had a previous write-up for automatic slat system and it had been deferred and subsequently cleared. Maintenance advised us that it may be a long delay to find the circuit that was causing the breaker to trip, or they could defer the automatic slat system again. Captain and I opted to defer the automatic slat system. Maintenance completed appropriate MEL paperwork and we proceeded to aus without incident, where we turned aircraft over to another crew. After sleeping on it, the following day, captain and I agreed that perhaps the wrong system had been deferred, ie, the automatic slat system probably was not working because the breaker kept tripping. Rather than deferring the automatic slat, we should have insisted on determining the cause of the tripped breaker before continuing the flight. Our desire to complete the last leg of the day along with maintenance's willingness to defer the symptom, but not necessarily the cause, combined to put an aircraft into service that probably should have been more thoroughly troubleshot first. Supplemental information from acn 512652: we got a stick shaker on landing rollout. After parking, we noticed a circuit breaker labeled 'smc-1.pac' aircraft was popped and would not reset. Stall warning #1 would not test. This had been a previous write-up and had been corrected and signed off a day or 2 before. It had tested ok earlier in the day. Note: this aircraft is different from most of the -300's. Do not have circuit breakers labeled 'smc-1.' also, there are only 2 circuit breakers for the autoslats labeled 'dc' not 'AC' -- as the case for most -300's. I feel that perhaps this aircraft (and maybe a few more) have some different 'oddball' system that controls more than just the automatic slat sensors, and maybe that system needs its own MEL.

Original NASA ASRS Text

Title: A B737-300 FLC HAS POSTFLT CONCERNS ABOUT THE MEL THAT WAS EXERCISED UPON A LEADING EDGE SLAT PROB THAT PERHAPS WAS ONLY PART OF THE REAL PROB AT HOU, TX.

Narrative: CHK OF MASTER CAUTION INBOUND TO HOU INDICATED A SINGLE CHANNEL FAILURE OF THE AUTO SLAT SYS. MAINT WAS ADVISED AND MET ACFT AT THE GATE. THEY DETERMINED THAT A CIRCUIT BREAKER BEHIND THE CAPT'S SEAT (EXACT BREAKER UNKNOWN) WAS POPPING AND CAUSING THE INDICATION. ACFT HAD A PREVIOUS WRITE-UP FOR AUTO SLAT SYS AND IT HAD BEEN DEFERRED AND SUBSEQUENTLY CLRED. MAINT ADVISED US THAT IT MAY BE A LONG DELAY TO FIND THE CIRCUIT THAT WAS CAUSING THE BREAKER TO TRIP, OR THEY COULD DEFER THE AUTO SLAT SYS AGAIN. CAPT AND I OPTED TO DEFER THE AUTO SLAT SYS. MAINT COMPLETED APPROPRIATE MEL PAPERWORK AND WE PROCEEDED TO AUS WITHOUT INCIDENT, WHERE WE TURNED ACFT OVER TO ANOTHER CREW. AFTER SLEEPING ON IT, THE FOLLOWING DAY, CAPT AND I AGREED THAT PERHAPS THE WRONG SYS HAD BEEN DEFERRED, IE, THE AUTO SLAT SYS PROBABLY WAS NOT WORKING BECAUSE THE BREAKER KEPT TRIPPING. RATHER THAN DEFERRING THE AUTO SLAT, WE SHOULD HAVE INSISTED ON DETERMINING THE CAUSE OF THE TRIPPED BREAKER BEFORE CONTINUING THE FLT. OUR DESIRE TO COMPLETE THE LAST LEG OF THE DAY ALONG WITH MAINT'S WILLINGNESS TO DEFER THE SYMPTOM, BUT NOT NECESSARILY THE CAUSE, COMBINED TO PUT AN ACFT INTO SVC THAT PROBABLY SHOULD HAVE BEEN MORE THOROUGHLY TROUBLESHOT FIRST. SUPPLEMENTAL INFO FROM ACN 512652: WE GOT A STICK SHAKER ON LNDG ROLLOUT. AFTER PARKING, WE NOTICED A CIRCUIT BREAKER LABELED 'SMC-1.PAC' ACFT WAS POPPED AND WOULD NOT RESET. STALL WARNING #1 WOULD NOT TEST. THIS HAD BEEN A PREVIOUS WRITE-UP AND HAD BEEN CORRECTED AND SIGNED OFF A DAY OR 2 BEFORE. IT HAD TESTED OK EARLIER IN THE DAY. NOTE: THIS ACFT IS DIFFERENT FROM MOST OF THE -300'S. DO NOT HAVE CIRCUIT BREAKERS LABELED 'SMC-1.' ALSO, THERE ARE ONLY 2 CIRCUIT BREAKERS FOR THE AUTOSLATS LABELED 'DC' NOT 'AC' -- AS THE CASE FOR MOST -300'S. I FEEL THAT PERHAPS THIS ACFT (AND MAYBE A FEW MORE) HAVE SOME DIFFERENT 'ODDBALL' SYS THAT CTLS MORE THAN JUST THE AUTO SLAT SENSORS, AND MAYBE THAT SYS NEEDS ITS OWN MEL.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A B737-300 flight crew has postflt concerns about the MEL that was exercised upon a leading edge slat problem that perhaps was only part of the real problem at hou, tx.