The reliable adhesive based joining of titanium components might enable new structural design concepts in aviation sector. Challenges are related to susceptiblity of Ti polymer interfaces to environmental ageing which leads to deadhesion. In this lecture a cohesive zone model (CZM) is presented. It reproduces roller peel test results and enables the correlation between industrial adhesion testing and physiochemical parameters acting at the respective interfaces. Aspects of semiconducting properties of very thin surface TiO2 films are considered as well as related adhesive failure modes. The studies have been conducted at N4 surface treated cp-Ti along aircraft standard testing procedures. Semiconducting properties of native titanium oxide films were derived from Electrochemical Impedance spectroscopy (EIS) and subsequent Mott-Schottky analysis. The influence of pre-treatments and bath aging has been studied utilizing computational parameter sweeps and the contribution of failure mechanism is described.