A B777 returned to field with #1 engine shutdown due to loss of oil quantity and pressure.

Attributes
ACN	345623
Time
Date	199608
Day	Sat
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
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	345623
Person 2
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	345204
Events
Anomaly	non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other flight crewa other other : unspecified cockpit
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

I and another mechanic were working on a change order on #1 engine on a B777. This change order replaces the main oil filter tube and scavenge oil pump. In the process of installation, a dust cap was inadvertently left installed at the filter housing where the oil tube connects. (This dustcap is a bayonet type and is not readily visible.) while the aircraft was in-flight the cap melted, and caused an in-flight shutdown due to loss of oil and pressure. In the future, this might be highly avoidable if all these caps are removed prior to routing of the line despite what the procedure recommends. The cap was discovered after the aircraft returned to the gate and the oil line was removed for inspection. Parts of the melted cap were found in the main oil screen. Supplemental information from acn 345204: on first engine run we had some small seepage around mating flange. Checked flange and had some gap between tube mating flange and seal. Re-torqued bolts for tube connection and discussed with another mechanic how gap might be caused by tube mating on crush type sealing gasket.

Original NASA ASRS Text

Title: A B777 RETURNED TO FIELD WITH #1 ENG SHUTDOWN DUE TO LOSS OF OIL QUANTITY AND PRESSURE.

Narrative: I AND ANOTHER MECH WERE WORKING ON A CHANGE ORDER ON #1 ENG ON A B777. THIS CHANGE ORDER REPLACES THE MAIN OIL FILTER TUBE AND SCAVENGE OIL PUMP. IN THE PROCESS OF INSTALLATION, A DUST CAP WAS INADVERTENTLY LEFT INSTALLED AT THE FILTER HOUSING WHERE THE OIL TUBE CONNECTS. (THIS DUSTCAP IS A BAYONET TYPE AND IS NOT READILY VISIBLE.) WHILE THE ACFT WAS INFLT THE CAP MELTED, AND CAUSED AN INFLT SHUTDOWN DUE TO LOSS OF OIL AND PRESSURE. IN THE FUTURE, THIS MIGHT BE HIGHLY AVOIDABLE IF ALL THESE CAPS ARE REMOVED PRIOR TO ROUTING OF THE LINE DESPITE WHAT THE PROC RECOMMENDS. THE CAP WAS DISCOVERED AFTER THE ACFT RETURNED TO THE GATE AND THE OIL LINE WAS REMOVED FOR INSPECTION. PARTS OF THE MELTED CAP WERE FOUND IN THE MAIN OIL SCREEN. SUPPLEMENTAL INFO FROM ACN 345204: ON FIRST ENG RUN WE HAD SOME SMALL SEEPAGE AROUND MATING FLANGE. CHKED FLANGE AND HAD SOME GAP BTWN TUBE MATING FLANGE AND SEAL. RE-TORQUED BOLTS FOR TUBE CONNECTION AND DISCUSSED WITH ANOTHER MECH HOW GAP MIGHT BE CAUSED BY TUBE MATING ON CRUSH TYPE SEALING GASKET.

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.