Technicians reported that rig pins were left installed after a flight control cable tension check. This was discovered during taxi for takeoff by the flight crew.

Narrative

Description of events that occurred with Aircraft X; relating to rig pins being left in after a tension check had been performed. I worked that night with one other Mechanic on the job card. Neither one of us had ever performed the job before; and the lead on the task was trying to rush us through a lot faster than what we felt comfortable with. I installed the all 5 rig pins that needed to be installed listed in the job card. 4 in the front; 1 in the back. It took us a while to figure everything out and to try and navigate the aircraft figuring out where things were; and what needed to be adjusted. When I installed the rig pins the 'remove before flight' tags had been curled up and zip tied; and I neglected to cut the flags loose. We worked for several hours trying to get everything completed. We did our best to follow all of the paperwork; but it was quite overwhelming and we didn't have a lot of direction. We finally finished with the tension check; and had made all the adjustments that needed to be made. I safety wired the turnbuckles; and was all set. I pulled the single pin in the back and the Inspector on the job said he wanted to check my safety wire work; and said that he would pull the rig pins up front. That particular Inspector can be very challenging to work with at times; and is not easy to confront or talk to very well; and I did not feel comfortable double checking his work; because I was afraid of how upset it might make him; and he is usually quite [detailed] with his tasks that I felt confident he had done what he needed to do. Shortly after we cleaned everything up and clocked out. I was under the impression that we were going to turn the job over to the next shift and that they would perform the ops check that would need done; and then sign off the rest of the paperwork. I didn't realize that the paperwork had gotten signed all the way through. NAME; the other Mechanic had taken that over; because there was quite a lot of paperwork to be managed and he took responsibility of that. But the ops check was not performed; and the airplane got pushed out with one of the rig pins still in place. Event was discovered soon after the aircraft was pushed back from the Gate; and the plane was preparing to taxi. Rig pin was left in a locking position. I was very upset with everything that happened and fully understand how serious all of this has been; along with how I could have performed my job better to prevent the incident. I would potentially add an ops check on the job-card itself and not just on the tension adjustment task. Because even though we had it out; it was overlooked; and I think having an operational check on the job card may have potentially prevented this issue.