This paper proposes a new inspection model for a multi-component system, subject to a deterioration process which impacts its efficiency. To control the deterioration process, several inspections are carried out after which various decisions are made on how to evaluate the functioning of the system. The proposed inspection model is applied on the case of Pitot sensors system for aircraft. This study is derived from an aeronautic problem defined following the crash of the Airbus 330 in the Rio-Paris flight. Since the Pitot sensors system is non-self-announcing, the paper proposes a technical solution which consists in setting up an additional self-control device in order to inspect and calibrate the already installed Pitot sensors measurements.The objective of this paper is to determine an optimal inspection policy which minimizes the total measurement quality degradation per unit of time in a finite time horizon. Numerical examples and a comparative study are provided to illustrate the proposed analytic model and to highlight the contribution of the paper.