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A B747-400 on first flight after maintenance shut down #4 engine in-flight due to loss of oil pressure and quantity caused by a loose oil line.
| Attributes | |
| ACN | 381887 |
| Time | |
| Date | 199710 |
| Day | Mon |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : zzz |
| State Reference | US |
| Altitude | agl bound lower : 0 agl bound upper : 0 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zdc |
| Operator | common carrier : air carrier |
| Make Model Name | B747-400 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | other |
| Flight Plan | None |
| Aircraft 2 | |
| Make Model Name | B747-400 |
| Operating Under FAR Part | Part 121 |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | other personnel other |
| Qualification | other other : other |
| ASRS Report | 381887 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | other personnel other |
| Qualification | other other : other |
| ASRS Report | 382439 |
| Events | |
| Anomaly | aircraft equipment problem : critical non adherence : far non adherence : published procedure other anomaly other |
| Independent Detector | other flight crewa other other : unspecified cockpit |
| Resolutory Action | other |
| Consequence | Other |
| Supplementary | |
| Air Traffic Incident | other |
Narrative:
I am an a&P mechanic at air carrier airlines based at the ZZZ maintenance facility. On oct/xx/97, I was given a job to complete a change order authority/authorized (coa) on a PW4000 engine. The coa involves changing an oil filter housing. My role in the job was to install clamps to secure oil lines and to install the filter. When the job was completed the engine was dry motored and ran to check for leaks but none were found. Later on the aircraft's first revenue flight the #4 engine lost oil quantity and had to shut down. It was discovered later that the oil pressure differential switch had a loose oil line. This switch is not part of the filter housing coa, however, the switch may have been loosened to access the filter housing. Engineers have been notified about this possible problem and they are in the process of changing the coa to include the removal/installation of this switch to access the filter housing.
Original NASA ASRS Text
Title: A B747-400 ON FIRST FLT AFTER MAINT SHUT DOWN #4 ENG INFLT DUE TO LOSS OF OIL PRESSURE AND QUANTITY CAUSED BY A LOOSE OIL LINE.
Narrative: I AM AN A&P MECH AT ACR AIRLINES BASED AT THE ZZZ MAINT FACILITY. ON OCT/XX/97, I WAS GIVEN A JOB TO COMPLETE A CHANGE ORDER AUTH (COA) ON A PW4000 ENG. THE COA INVOLVES CHANGING AN OIL FILTER HOUSING. MY ROLE IN THE JOB WAS TO INSTALL CLAMPS TO SECURE OIL LINES AND TO INSTALL THE FILTER. WHEN THE JOB WAS COMPLETED THE ENG WAS DRY MOTORED AND RAN TO CHK FOR LEAKS BUT NONE WERE FOUND. LATER ON THE ACFT'S FIRST REVENUE FLT THE #4 ENG LOST OIL QUANTITY AND HAD TO SHUT DOWN. IT WAS DISCOVERED LATER THAT THE OIL PRESSURE DIFFERENTIAL SWITCH HAD A LOOSE OIL LINE. THIS SWITCH IS NOT PART OF THE FILTER HOUSING COA, HOWEVER, THE SWITCH MAY HAVE BEEN LOOSENED TO ACCESS THE FILTER HOUSING. ENGINEERS HAVE BEEN NOTIFIED ABOUT THIS POSSIBLE PROB AND THEY ARE IN THE PROCESS OF CHANGING THE COA TO INCLUDE THE REMOVAL/INSTALLATION OF THIS SWITCH TO ACCESS THE FILTER HOUSING.
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.