Air carrier technician reported the Right Hand Main Landing Gear Downlock Pin was not removed prior to flight; causing the aircraft to return to the airport due to the Main Landing Gear not retracting on takeoff.
Synopsis
Air carrier technician reported the Right Hand Main Landing Gear Downlock Pin was not removed prior to flight; causing the aircraft to return to the airport due to the Main Landing Gear not retracting on takeoff.
Narrative
I was told to take Aircraft X to the terminal by my supervisor around XA30 am; which was located on the ramp at the far side of the contract repair station. Following my Run/Taxi checklist I started doing my inspection and I noticed two gear pins were installed in the aircraft: NLG and LH MLG. Person A then proceeded to remove the NLG as I removed the LH MLG pin. As I continued with my inspection i did not see a third pin on the RH MLG due to the lack of the red lanyard that is supposed to be attached to the pin. Person A also did not see the pin. I continued to follow my Maintenance run/taxi checklist and I was done with my inspection outside so I proceeded to go inside the aircraft. Aircraft was taxi to the gate and it was left in a conditions as per Maintenance Run/Taxi checklist. After take off; the RH MLG would not retract so the pilot had to RTF (Return to Field) and later was noticed upon inspection that a gear pin was still in the RH MLG without the remove before flight red Lanyard.Suggestion: To add install/remove gear pins from aircraft in the Maintenance Run/Taxi checklist just like the Pilot's preflight checklist
Second reporter narrative
Yesterday morning at XA:30 AM I was told by my supervisor to take Aircraft X to the gate with. The aircraft was parked next to the contract repair station; we took the stairs and when we got there; Person B started to do the walk around inspection. I removed the NLG pin and Person B removed the LH MLG and gave it to me; before continuing his inspection on the other side. He noticed that there were some loose screws on both the LH and RH wing roots; and called a fellow mechanic to bring some tools out and get the issue resolved. I did not notice that the pin had not been removed from the RH MLG because the lanyard attached to it was missing and assumed my partner already pulled it. I returned to the cockpit with the 2 pins while my partner was still doing the walk around and inserted the pins; and forgot to question him about the missing pin. The aircraft was then taxied to the gate and left in a condition per maintenance Run/Taxi checklist. After take off the RH MLG would not retract so the pilot had to RTF and later noticed that the gear pin was still installed in the RH MLG without the 'remove before flight ' lanyard attached. Suggestion: Include the installation/removal of gear pins from aircraft in the maintenance Run/Taxi checklist; or exclude us from the pin removal/installation process
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.