The present work proposes a pragmatic requirements validation method through simulation. First, A Bond Graph model for a light business aircraft and its brake system created. The dynamic response of the aircraft considers the forces acting on a concentrated point. Two dual stage servo valve, the hydraulic tubing and hoses, and brake-wheel-tire behavior are considered on the analysis. An On-Off anti-skid system is implemented. The simulations are run using 20-Sim® software. The results obtained through it are used to calculate the braking efficiencies at A/C and system levels. Braking performance efficiency is assessed on A/C level through ?brake_AC method, and at system level considering three different methods: Torque Method Efficiency (AC 25-7D), Stopping Distance Efficiency and Developed Mu Efficiency Methods (SAE AIR1739B).Then, these values are used as the performance criteria for the requirements definition on each level. Therefore, a robust and tightly coupled set of requirements is generated to guarantee the link between the two different layers of specifications. Additionally, a robust assessment of the system performance is evaluated. Therefore, the present work encourages system and performance engineers to define more accurate requirements on the early phases of the aircraft development.