A320
Distraction; Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Gate; General Maintenance Action
Human Factors
While working on an Flight Control Data Concentrator (FCDC) #2 write-up; my partner notified me that; while in the main avionics compartment; that he noticed the Engine Interface Unit (EIU) #2 hold down knobs were loose but that the EIU was securely seated in its rack. No further info was given to me at that time and I was under the belief that he was taking responsibility to secure the loose EIU hold down knobs. After this information was given to me I continued and then completed my repair of the FCDC #2 problem. Shortly after the aircraft pushed off the gate; my co-worker asked me if I had tightened the EIU #2 hold down knobs. I told him that I did not because I was under the impression that he had taken responsibility to correct that discrepancy. He immediately informed a Maintenance Lead of the unsecure EIU #2 and requested that the aircraft return to the gate. The aircraft returned and the discrepancy was corrected and documented. The aircraft then departed with no further incident.
Crew refusal for FCDC 2 fault; previously placed on MEL 2795A; my partner and I then worked other maintenance items on 2 gates. We were given a new FCDC to install. I opened main equipment avionics door for access to FCDC 2; while my partner; and setup the cockpit for replacement. I noticed the EIU 2 was seated in the rack near the door with the hold down knobs loose. I went upstairs to let my partner know door was open and that I found the knobs loose on EIU 2. A few minutes later; I was called on the radio that 3 each seat covers were needed on another aircraft. I left to take care of seat covers. When I was finished; I met my fellow Mechanic who said Aircraft FCDC 2 was replaced and ready. As soon as I realized the aircraft was taxiing out and the holddown knobs were not tightened; I immediately contacted Company Bravo South Lead; so Aircraft X could be returned to the gate for recheck of holddown knobs. Aircraft gate returned approximately an hour later. Both EIU 2 knobs were tightened. Log item was addressed thru maintenance data and released.
Two mechanics report an aircraft nearly taxied out without having the Engine Interface Unit (EIU) 2 hold down knobs tightened.