5. Conclusion
Fatigue and overstress of the principal structural element are crucial problems for all categories of aircraft. Light and Ultra-Light aircraft have limited opportunities for the application of advanced Structural Health Monitoring Systems. That is why the autonomous Surface Relief Fatigue Indicator (SRFI) may be considered as a reliable tool for the fatigue monitoring.
Light and Ultra-Light due to the action of the unallowable accelerations in manoeuvers meet the overstress conditions for the components. The excessive stresses can lead to the deformation of the structure, loss of the aerodynamic characteristics and even to an aircraft crash. The overstress can be revealed by the simple proposed device, called here Overstress Indicator. It allows for prevention flight with damaged structure, thus increases the safety of the operation.