Aircraft operation in apparent violation of minimum equipment list.

Attributes
ACN	140564
Time
Date	199003
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air taxi
Make Model Name	Helicopter
Flight Phase	ground : preflight
Flight Plan	None
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : commercial
Experience	flight time last 90 days : 55 flight time total : 5500 flight time type : 100
ASRS Report	140564
Person 2
Affiliation	company : air taxi
Function	other personnel other
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : less severe non adherence : far other anomaly other
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
Publication	Unspecified

Narrative:

On 3/tue/90, at approximately XA00 hours, I was en route from ZZZ airport to medical center. While over XXX the master caution and forward fuel transfer pump caution light illuminated. Inspection of the circuit breaker revealed that it had tripped. Upon resetting the circuit breaker, the caution light remained illuminated and within 10 seconds, the circuit breaker tripped again. I elected to return to ZZZ airport where our maintenance had been working on this aircraft. After shutdown 1 mechanic determined that the pump had seized while the lead mechanic and I examined the MEL for the condition. I opened the MEL to the table of contents and located the relevant chapter, turned to the page indicated and read the specific entry. To ensure that I understood the entire entry I then turned to the explanation of abbreviations and in conjunction with the lead mechanic, determined that operation was authority/authorized with the remaining pump with the caution light placarded inoperative. The lead mechanic commented that this must be a new change as the condition had previously prevented continued operation. The caution light was placarded and I then flew the aircraft to our original destination and placed the aircraft in service for EMS operations. No further flts were required for the remainder of my shift. At approximately XB00 hours I discovered that no maintenance entry had been made so I made the appropriate entry and signed off the discrepancy under my a&P license. At approximately XC30 hours, my relief arrived and I gave him my shift report, including reference to the defective pump. The following morning, the lead mechanic that had the previous day examined the MEL with me called to inform me that what we had in fact read was the criteria for the forward transfer pump caution light inoperative procedure. During the elapsed time to my notification, 2 additional pilots had flown the aircraft in this condition. In short, 3 pilots and 2 mechanics had misread or misunderstood the MEL. In addition, a mechanic responsible for issuing job orders in connection with parts ordering had confirmed the mechanic's comments that the aircraft was operable with 1 transfer pump inoperative.

Original NASA ASRS Text

Title: ACFT OPERATION IN APPARENT VIOLATION OF MINIMUM EQUIPMENT LIST.

Narrative: ON 3/TUE/90, AT APPROX XA00 HRS, I WAS ENRTE FROM ZZZ ARPT TO MEDICAL CENTER. WHILE OVER XXX THE MASTER CAUTION AND FORWARD FUEL TRANSFER PUMP CAUTION LIGHT ILLUMINATED. INSPECTION OF THE CIRCUIT BREAKER REVEALED THAT IT HAD TRIPPED. UPON RESETTING THE CB, THE CAUTION LIGHT REMAINED ILLUMINATED AND WITHIN 10 SECS, THE CIRCUIT BREAKER TRIPPED AGAIN. I ELECTED TO RETURN TO ZZZ ARPT WHERE OUR MAINT HAD BEEN WORKING ON THIS ACFT. AFTER SHUTDOWN 1 MECH DETERMINED THAT THE PUMP HAD SEIZED WHILE THE LEAD MECH AND I EXAMINED THE MEL FOR THE CONDITION. I OPENED THE MEL TO THE TABLE OF CONTENTS AND LOCATED THE RELEVANT CHAPTER, TURNED TO THE PAGE INDICATED AND READ THE SPECIFIC ENTRY. TO ENSURE THAT I UNDERSTOOD THE ENTIRE ENTRY I THEN TURNED TO THE EXPLANATION OF ABBREVIATIONS AND IN CONJUNCTION WITH THE LEAD MECH, DETERMINED THAT OPERATION WAS AUTH WITH THE REMAINING PUMP WITH THE CAUTION LIGHT PLACARDED INOP. THE LEAD MECH COMMENTED THAT THIS MUST BE A NEW CHANGE AS THE CONDITION HAD PREVIOUSLY PREVENTED CONTINUED OPERATION. THE CAUTION LIGHT WAS PLACARDED AND I THEN FLEW THE ACFT TO OUR ORIGINAL DEST AND PLACED THE ACFT IN SVC FOR EMS OPS. NO FURTHER FLTS WERE REQUIRED FOR THE REMAINDER OF MY SHIFT. AT APPROX XB00 HRS I DISCOVERED THAT NO MAINT ENTRY HAD BEEN MADE SO I MADE THE APPROPRIATE ENTRY AND SIGNED OFF THE DISCREPANCY UNDER MY A&P LICENSE. AT APPROX XC30 HRS, MY RELIEF ARRIVED AND I GAVE HIM MY SHIFT RPT, INCLUDING REF TO THE DEFECTIVE PUMP. THE FOLLOWING MORNING, THE LEAD MECH THAT HAD THE PREVIOUS DAY EXAMINED THE MEL WITH ME CALLED TO INFORM ME THAT WHAT WE HAD IN FACT READ WAS THE CRITERIA FOR THE FORWARD TRANSFER PUMP CAUTION LIGHT INOP PROC. DURING THE ELAPSED TIME TO MY NOTIFICATION, 2 ADDITIONAL PLTS HAD FLOWN THE ACFT IN THIS CONDITION. IN SHORT, 3 PLTS AND 2 MECHS HAD MISREAD OR MISUNDERSTOOD THE MEL. IN ADDITION, A MECH RESPONSIBLE FOR ISSUING JOB ORDERS IN CONNECTION WITH PARTS ORDERING HAD CONFIRMED THE MECH'S COMMENTS THAT THE ACFT WAS OPERABLE WITH 1 TRANSFER PUMP INOP.

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.