Which of the following is required for returning an aircraft to service after a 100 hour inspection?

Returning an aircraft to service after a 100 hour inspection necessitates specific documentation to ensure compliance with regulations and maintain the aircraft's airworthiness. The correct answer highlights the need for an entry that includes crucial information about the inspection that has just been completed. This entry must specify the type of inspection performed, the date it was conducted, the condition of the aircraft at the time of inspection, and the signature of the authorized person who performed the inspection.

This documentation is essential because it serves as a record that demonstrates compliance with the regulatory requirements set forth by the Federal Aviation Administration (FAA). It provides verification that the aircraft has been inspected thoroughly and meets all necessary standards for safety and operational performance. Such entries are vital for maintaining accurate maintenance records, which are critical for ongoing airworthiness and in case of future inspections or audits.

In contrast, while previous inspections, upcoming maintenance types, and modifications are important aspects of an aircraft's overall maintenance history, they are not specifically mandated for the returning to service process immediately following a 100 hour inspection. The focus after such an inspection is ensuring that all pertinent information related to that particular inspection is accurately documented and recorded.