37 Maintenance of aircraft, namely, overhauling, servicing, repairing, cleaning, washing and refurbishing, aircraft and their component parts, in particular their nacelles; conversion of aircraft, namely, reconditioning and installing used or partly destroyed equipment on aircrafts and installing equipment to allow aircraft engines to use hybrid power; servicing of aircraft, namely, overhaul, maintenance, repair, cleaning and washing of aircraft nacelles, aircraft engines, aircraft appliances, aircraft aeronautical equipment, aircraft avionic systems and hydraulic or pneumatic parts; assembly and repair of spare parts for aircraft nacelles, aircraft, avionics, hydraulic or pneumatic equipment or parts and fittings for air vehicles on behalf of airlines; replacement of aircraft nacelle parts, aeronautical, avionics, hydraulic or pneumatic equipment or parts and fittings for air vehicles on behalf of airlines; installation of replacement parts for air vehicles and their constituent parts, notably nacelles; construction supervision, namely, direction and coordination of services for the construction, maintenance, overhaul, servicing, cleaning, washing, repairing, refurbishing, converting or fitting out of any aircraft, their component parts, including their nacelles; building construction; vehicle repair in the event of vehicle breakdowns, in particular of aerial vehicles; refurbishment of vehicles, in particular aircraft; refurbishment of worn-out or partially destroyed aircraft nacelles; refurbishment of worn-out or partially destroyed machinery; refurbishment of worn out or partially destroyed engines; anti-rust treatment, namely, preventive rust treatment for vehicles; aircraft and airport maintenance services, namely, overhauling, cleaning, washing, and repair of all airport and airline safety equipment, in particular on board aircraft, in airports or in airport areas; sealing services to insulate aircraft equipment and aircraft component parts from humidity, air pressure and extreme temperatures; installation of insulating materials; information services relating to aircraft and airport maintenance, namely, with regard to the servicing, overhaul, maintenance, cleaning, washing or repair of all aircraft, their component parts, in particular their nacelles, appliances, equipment, aeronautical or avionic apparatus, hydraulic or pneumatic parts of airports and airport infrastructure and buildings; technical advice in the field of aircraft engine repair; technical or technological advice relating to aircraft, in particular aircraft nacelles, namely, technical or technological advisory services relating to power systems installation and reconditioning, telecommunication equipment installation and reconditioning, and fire prevention equipment installation and reconditioning