A novel approach for aerial drone control in object pickup tasks is presented. The methodology integrates quaternion-observer control to address the challenge of variable mass during object interaction. A specialized non-actuated gripper designed explicitly for aerial drones enhances their ability to grasp objects efficiently. Real-time tests validated the effectiveness and feasibility of the proposed solution. The experiments demonstrated the robustness and adaptability of quaternion-observer control in compensating for variable mass during object pickup tasks. Additionally, the practical utility of the non-conventional gripper design under real-world conditions emphasized its relevance in aerial manipulation scenarios.