Abstract This paper presents ProLiCES, an approach for the development of safety-critical embedded applications and its usage to develop a product line for unmanned aerial vehicles (UAV). The motivation of ProLiCES emerged after the development of Tiriba, a family of small, electric-powered unmanned aircraft. Most software artifacts produced for Tiriba required modifications to be reused in a more complex project, the SARVANT, which has to accommodate several new features that increase the variability of the end products. In the Tiriba project, a methodological approach, named SAFE-CRITES, was defined and used. Special care was taken about software reuse, based on Model Driven Development and automatic code generation. The certification process, based on the DO-178B standard, was also taken into account. ProLiCEs extends SAFE-CRITES to integrate Product Line Engineering into the development process, aiming better software reuse. This extension was done by creating a second parallel path to the process, dealing with the Product Line Domain Engineering. ProLiCES is being currently used in the SARVANT project, which will deliver a much more complex UAV and is estimated to be deployed in two years.