ATR 42
Maintenance Airframe; Maintenance Powerplant
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft Aircraft Damaged; General Maintenance Action
Procedure; Weather
I was assigned to perform a pushback for Flight XXX. Once the CA and FO completed their preflight checklist; they asked to have ground air removed from the aircraft; then we continued with running engine #2; followed by removing GPU; releasing brakes and pursuing the pushback. As a new hire mechanic for this was my third attempt at a pushback with a tug in tow. At this time in the morning; we had a mist followed by a period of light rain and calm winds. Inexperienced; I proceeded to pushback with my fellow A&P mechanic on my right hand side guiding me and giving me hand signals to guide the tug. I was instructed by him to let go of the brake from the tug and let the tug push without using any acceleration and use the accelerator if need be. At this point I approached an unmarked portion of the ramp providing the place where I should be turning the plane for taxiing. As I am proceeding to turn; I noticed and was instructed that there is no indication on the NLG (Nose Landing Gear) door to where the 91 degree mark is (beyond or exceeding the turning radius). At this point; once I turned I notice that I turned too hard going beyond the point taking into consideration that there is no indication anywhere specifying turning radius. Once I came to a complete stop; I notified the CA and FO to set the brakes; once the brakes were set; the rampers released the tow bar from the plane and I backed up about 3 feet and then the tow bar was placed on the tug; removed the safety pin; verified that the pin was removed with CA and FO; rampers removed the phone jack and closed the GPU panel. I then drove off to the gate and noticed that the shear pin was sheared off and the tow bar was bent. I then notified my supervisor. I inspected the NLG and found that the bobbins on both sides were fractured. The plane was then grounded.
Technician reported that while pushing back an aircraft; the maximum turning radius for the Nose Landing Gear was exceeded; causing damage to the aircraft.