A320
Maintenance Airframe; Maintenance Powerplant
Situational Awareness
Aircraft Equipment Problem Critical
General None Reported / Taken
Aircraft; Equipment / Tooling
Employee Mechanic Y and I were conducting maintenance on the right-hand main landing gear of an A320 aircraft while the main landing gear was mounted on the Omni-arm. We were articulating the landing gear to a near horizontal position to facilitate seal replacement. While rotating it to a horizontal position the Omni-Arm suddenly released from its rotating position and suddenly dropped without command 10'-12' inches. Employees Mechanic Y; Z and Supervisor observed this mishap event.
A Line Mechanic reports about an A320 right Main Landing Gear (MLG) suddenly releasing and dropping 10' to 12' inches; uncommanded; from an Omni Arm landing gear support equipment. They were rotating the MLG to a horizontal position using the Omni Arm device to facilitate seal replacement.