Date: 201909
Location: ZZZZ.Airport, FO
Aircraft: B787-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Pax Seat
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown; Time Pressure; Workload
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Aircraft In Service At Gate
Result: General None Reported / Taken
Contributing factors: Aircraft; Human Factors; Procedure; Incorrect / Not Installed / Unavailable Part
Primary problem: Human Factors

Narrative: Aircraft X arrived to ZZZ; approximately 5 minutes before boarding started; I received a call to go back onboard because the seat 3D leg rest wouldn't stow. After a quick inspection; we found that the actuator was seized and required changing; I immediately called a colleague in the office to check for availability of the part; when he confirmed that the part was available in stock I proceeded to remove the defective part while he ordered it and delivered it to us.Boarding started; passengers were around us awaiting to use seat and adjacent one; and after installation; we noted that the part did not operate; which made us think that another fault had caused the previous actuator to get jammed and we decided to defer due time in the now available stowed position with the leg rest actuator deactivated and stowed.Approximately 27 hrs after; at the end of my next work day; during another ETOPS check; a different colleague asked me; in this case; to check for availability of the exact same actuator for a different aircraft; during the research in the Config drawings I realized that some aircraft had now a new [Engineering Order] applied and the part number was different than the one I installed a day ago and we didn't have in stock the required part; at that moment; I realized that my biggest fear had occurred; 'I installed an incorrect part on an aircraft'; at that point; I updated the item with the correct material and labor that is required to do the correct fix.I know that I am the ultimate responsible for checking effectivity before installing any part on any aircraft; I also know that I even if someone orders a part for me I am the ultimate person responsible to verify its effectivity and this has taught me a valuable lesson to check again even if you have done the same procedure many times; even more if somebody else is doing that procedure for you or the parts look identicalToday; just 12 hrs after I found out about this mistake and back on my shift; I had spoken with our Supervisors of the station and with my fellow Crew Chiefs/Leads about this mistake to raise awareness and use it as an example and good reminder that even though we have been working in the same model of seat that visually didn't show any changes over the years; there are some parts that could have changed and are no longer effective and we always need to check before installing a part.I have spoken to the colleague who ordered the part for me and he said 'he used the number we have always used' because of the rush of the situation and didn't check the effectivity because 'it is the same seat as always' and 'it is the same actuator as always.' He apologized to me and ultimately I don't fault him because I am the responsible to check effectivity when I install a part.I have raised awareness on my station already that we must always check effectivity of parts when installing and look for any document that might supersede previous documents. Also I have discussed with my colleagues that we must not allow ourselves to make mistakes by trying to achieve the time targets of departure when we are dealing with something as delicate as changing parts or doing important inspections. That was my resolution at this station; I do not know if this specific problem has been happening worldwide but the resolution is to raise awareness.




Synopsis: Technician reported that while replacing a seat actuator; a fellow Technician provided an actuator with the wrong part number which he installed and subsequently deferred for non-operation.