The advent of artificial intelligence (AI) and unmanned aerial vehicles (UAVs) has ushered in a new era for railway engineering in preventive maintenance and inspection. This paper presents a conceptual study on using AI drones for the inspection, maintenance, and enhancement of railway safety. Focusing on a futuristic perspective, the study discusses how data collection via AI, predictive maintenance through machine learning, and computer vision can transform the evaluation of railway assets (track, OHE, bridges, tunnels, etc.). The paper describes the current practices in significant railways, highlighting the gains in efficiency, accuracy, and safety that automated drone systems can provide. It also addresses the technical challenges, regulatory limitations, and ethical concerns associated with these technologies. The discussion, along with a summary table of AI-powered drone applications and a mermaid diagram of an integrated railway monitoring system, offers a comprehensive view of the subject. The results indicate that AI, IoT, and digital twin technology can revolutionise railway maintenance efforts, resulting in reduced downtime and minimised risks. The paper concludes with suggestions for future work aimed at optimising AI algorithms, improving data processing, and developing regulatory frameworks for the public use of autonomous drones in railways.