A B737-500 was dispatched with the right engine starter drive shaft 'O' ring seal not installed.

Attributes
ACN	719511
Time
Date	200610
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Person 1
Affiliation	company : air carrier
Function	maintenance : lead technician
Qualification	technician : airframe technician : powerplant
ASRS Report	719511
Person 2
Affiliation	company : air carrier
Function	maintenance : technician
Events
Anomaly	maintenance problem : improper maintenance maintenance problem : improper documentation non adherence : far non adherence : published procedure
Independent Detector	other other : 1
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	contributing factor : lighting contributing factor : schedule pressure performance deficiency : installation performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Environmental Factor Maintenance Human Performance Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

During #2 engine starter pad garlock seal removal due to oil leaking through drain pad while engine was running. I have done many of these seals in past; but this time I forgot to check an 'O' ring which goes around outside diameter of seal. After installation we leak check engine. No oil leak was noted and aircraft took off for next destination. After awhile when I was gathering old parts and my tools I discovered that 'O' ring was still in kit; so I immediately called maintenance control and filed as soon as possible report. I can only say not having enough light I missed that 'O' ring. It was kind of dark and I overlooked it.

Original NASA ASRS Text

Title: A B737-500 WAS DISPATCHED WITH THE R ENG STARTER DRIVE SHAFT 'O' RING SEAL NOT INSTALLED.

Narrative: DURING #2 ENG STARTER PAD GARLOCK SEAL REMOVAL DUE TO OIL LEAKING THROUGH DRAIN PAD WHILE ENG WAS RUNNING. I HAVE DONE MANY OF THESE SEALS IN PAST; BUT THIS TIME I FORGOT TO CHK AN 'O' RING WHICH GOES AROUND OUTSIDE DIAMETER OF SEAL. AFTER INSTALLATION WE LEAK CHK ENG. NO OIL LEAK WAS NOTED AND ACFT TOOK OFF FOR NEXT DEST. AFTER AWHILE WHEN I WAS GATHERING OLD PARTS AND MY TOOLS I DISCOVERED THAT 'O' RING WAS STILL IN KIT; SO I IMMEDIATELY CALLED MAINT CTL AND FILED ASAP RPT. I CAN ONLY SAY NOT HAVING ENOUGH LIGHT I MISSED THAT 'O' RING. IT WAS KIND OF DARK AND I OVERLOOKED IT.

Data retrieved from NASA's ASRS site as of January 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.