Model-Checking Real-Time Properties of an Aircraft Landing Gear System Using Fiacre

We describe our experience with modeling the landing gear system of an aircraft using the formal speci cation language Fiacre. Our model takes into account the behavior and timing properties of both the physical parts and the control software of this system. We use this formal model to check safety and real-time properties on the system but also to nd a safe bound on the maximal time needed for all gears to be down and locked (assuming the absence of failures). Our approach ultimately relies on the model-checking tool Tina, that provides statespace generation and model-checking algorithms for an extension of Time Petri Nets with data and priorities.