Mechanic describes how a CSD oil cooler change and an 'out of the ordinary' servicing of the #1 engi...

Attributes
ACN	801751
Time
Date	200807
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Flight Phase	ground : maintenance
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	801751
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : published procedure non adherence : far
Independent Detector	other other : 1
Resolutory Action	none taken : detected after the fact
Consequence	other
Factors
Maintenance	performance deficiency : non compliance with legal requirements performance deficiency : installation
Supplementary
Problem Areas	Aircraft Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

I have been notified on my return from days off that #1 engine oil cap on aircraft was left off after servicing on jul/xa/08. This was my assigned aircraft for the night. A CSD cooler change was taking place on #1 engine that may have contributed to the incident. While working the CSD oil cooler change with the reverser and fan cowling open; I also svced the #1 engine oil. Doing so with the cowlings open was an out of the ordinary procedure for me. Normally for the past 25 yrs I have always svced the oil through the service panels of the engine and then reopened the door to doublechk the cap. With the cowlings open; this was not possible and was not my normal procedure. In retrospect; when operating outside of your normal procedures; you must be more diligent in checking your work. This goes back to our human factors issues that we must keep in mind.

Original NASA ASRS Text

Title: MECHANIC DESCRIBES HOW A CSD OIL COOLER CHANGE AND AN 'OUT OF THE ORDINARY' SERVICING OF THE #1 ENG OIL; WITH THE ENG COWL OPEN; MAY HAVE CONTRIBUTED TO THE OIL CAP BEING LEFT OFF ON A B737-300.

Narrative: I HAVE BEEN NOTIFIED ON MY RETURN FROM DAYS OFF THAT #1 ENG OIL CAP ON ACFT WAS LEFT OFF AFTER SVCING ON JUL/XA/08. THIS WAS MY ASSIGNED ACFT FOR THE NIGHT. A CSD COOLER CHANGE WAS TAKING PLACE ON #1 ENG THAT MAY HAVE CONTRIBUTED TO THE INCIDENT. WHILE WORKING THE CSD OIL COOLER CHANGE WITH THE REVERSER AND FAN COWLING OPEN; I ALSO SVCED THE #1 ENG OIL. DOING SO WITH THE COWLINGS OPEN WAS AN OUT OF THE ORDINARY PROC FOR ME. NORMALLY FOR THE PAST 25 YRS I HAVE ALWAYS SVCED THE OIL THROUGH THE SVC PANELS OF THE ENG AND THEN REOPENED THE DOOR TO DOUBLECHK THE CAP. WITH THE COWLINGS OPEN; THIS WAS NOT POSSIBLE AND WAS NOT MY NORMAL PROC. IN RETROSPECT; WHEN OPERATING OUTSIDE OF YOUR NORMAL PROCS; YOU MUST BE MORE DILIGENT IN CHKING YOUR WORK. THIS GOES BACK TO OUR HUMAN FACTORS ISSUES THAT WE MUST KEEP IN MIND.

Data retrieved from NASA's ASRS site as of May 2009 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.

Mechanic describes how a CSD oil cooler change and an 'out of the ordinary' servicing of the #1 engine oil; with the engine cowl open; may have contributed to the oil cap being left off on a B737-300.