ATA Specification 400 is a standard developed by the Air Transport Association that outlines the requirements for the electronic exchange of aviation maintenance data. It aims to improve communication and efficiency in the aviation industry by providing a consistent framework for data sharing among various stakeholders, including airlines, manufacturers, and maintenance organizations. The specification covers various aspects of maintenance data, including reporting formats, data structures, and communication protocols. By standardizing these elements, ATA Specification 400 helps ensure that all parties involved in aircraft maintenance can access and interpret data accurately, ultimately enhancing safety and operational efficiency in aviation.