EMB ERJ 170/175 ER/LR
Distraction; Situational Awareness; Time Pressure; Workload
Deviation / Discrepancy - Procedural Published Material / Policy
Equipment / Tooling; Human Factors
I was sent to a gate call on Aircraft X to change a Left-Hand Wing Taxi Light that was cracked. I arrived at the aircraft to assess the situation and then went inside the cockpit to grab the logbook. The FO (First Officer) told me he found the discrepancy during the walk around; and I told him not to worry. I disabled and locked the taxi light virtual CB (Circuit Breaker) via the MCDU (Multipurpose Control Display Unit); so there [was] no electricity flow and then went downstairs to fix the issue. I went to the vehicle I was using and grabbed three items: a new taxi light; my screwdriver and a small red box with different screwdriver bits. I placed the taxi light and screwdriver on the ground but the small red box I left it on left-hand engine strake. I proceeded to replace the Left-Hand Taxi Light; finished the job; and then I proceeded to take all the items I used. I signed the logbook inside my vehicle and called [Maintenance Control] to put the plane back to service. I was focused on finishing the job and signing the logbook and making sure the plane was good to go that I forgot to check the spot where I worked for any items that I may forgot. I gave the logbook back to the FO stating the change of the new taxi light; enable the CB on that taxi light and do another operational check of the light with the crew. I usually double check the area that I worked for any item I may left; but this time thinking that I retrieved all my work items; [I] did not double check. I went back to the shop to document the paperwork on the computer and give it to my Supervisor. The time pass by; and twenty minutes later my Supervisor tells me that if by any chance I may [have] forgot a tool on the aircraft. At [that] moment I [remembered] that I took all the items I used except for the small red box with screwdriver bits on the engine strake. I immediately went to retrieve the item I left on the aircraft but was given to me by ramp personnel. I feel ashamed because due to my carelessness; I almost posed a safety issue to the passengers aboard and the aircraft itself for leaving a tool. The only thing I can do to make up to my mistake is to never leave a tool anywhere on the aircraft and leave my tools inside the tool bag whenever I used them.
E175 Maintenance Technician reported leaving a tool on the aircraft engine after completing work.