This chapter delves into the innovative development and characterization of self-healing nanocomposites, highlighting their potential to significantly improve the safety, longevity, and performance of aerospace materials. Self-healing nanocomposite materials are engineered to provide for real-time in situ damage repair, thereby extending the lifespan of aerospace components and reduce their maintenance cost. This review explores various self-healing mechanisms, including microencapsulation, remediation of cracks and networks, and intrinsic self-healing through the engagement of reversible chemical bonds, often driven by shape memory of materials. Key focus areas include the synthesis and integration of self-healing agents within the nanocomposite matrix. Microencapsulation techniques involve embedding healing agents within microcapsules that rupture upon damage, releasing the healing agent to fill the cracks and restore its original structural integrity. Vascular networks mimic biological systems with microchannels delivering healing agents to the damaged sites. Intrinsic self-healing utilizes materials that can reversibly bond or deform under specific conditions, thus allowing for repeated healing cycles. Mechanical testing, including tensile, flexural, and fatigue tests, assess the durability and effectiveness of the self-healing mechanisms under simulated aeronautical conditions. This in turn governs the potential applications of these advanced materials in aeronautical engineering, highlighting their promise in improving safety, reducing downtime, and enhancing the performance of aerospace components. This chapter captures the salient features of self-healing mechanisms and their potential applications in aerospace materials, in particular.