The French Air-Cobot project aims at improving preflight maintenance as well as providing a traceability of the performed checks. A collaborative mobile robot has been built in order to carry out those tasks. The robot is able to navigate autonomously around the aircraft and perform non-destructive testing thanks to several sensors. More precisely, in this paper we focus on how to obtain a correct position of the 3D scanner fixed on a scissor with respect to the aircraft. It acquires 3D data which is analyzed to process surface inspection. The functional safety of the scissor is based on automatic visual checking of some cues. The full process demonstrates the feasibility of integrating 3D sensor on a mobile platform in safe conditions.