DC-9 Undifferentiated or Other Model
Maintenance Airframe; Maintenance Powerplant
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft; Human Factors; Procedure
I signed off a Service Check inspection and then signed the Airworthiness Release for its flight. The aircraft departed flying to its destination. I was informed that I needed to complete this report due to the fact that after the aircraft landed; the #1 engine oil reservoir cap was left off during servicing by the previous shift. During its flight; the oil in the #1 engine reservoir slowly exited the tank out the open servicing port and landed with only four quarts reading on the quantity indicator. The oil tank was re-serviced and the cap secured for the return flight. According to the DC-9 Maintenance Manual; engine oil servicing must be accomplished within 30 minutes of engine shutdown; which was accomplished on the previous shift. When we accomplish the Service Checks on our DC-9s; the aircraft have been on the ground for several hours already. We usually check the oil quantity indicators in the flight deck to verify they read 12 quarts or more. If an indicator reads less than 12 quarts; we will run the affected engine for two minutes and check oil at the reservoir. As the indicators on this aircraft both read over 12 quarts during our Service Check; we did not look at the reservoirs and notice the oil reservoir cap was off.In the future we will specifically check the oil reservoir caps for security on our DC-9 engines during every Daily and Service Check inspection.
Technician reported a DC-9 oil reservoir cap was left off of Number 1 engine.