What defines a 100-hour inspection?

A 100-hour inspection is a specific type of maintenance check required by regulations for aircraft that are used for hire or for flight instruction. This inspection is designed to ensure the continued airworthiness of the aircraft between more comprehensive annual inspections.

What sets the 100-hour inspection apart is that it covers a wide range of items, including mandatory checks on the airframe, engine, and safety equipment, similar to what is evaluated in an annual inspection. Both inspections require thorough examination of critical aircraft components to ensure safety and compliance with aviation standards. Therefore, the 100-hour inspection includes a review that aligns closely with what is mandated during an annual inspection, making it a comprehensive assessment rather than a limited check.

This relationship highlights that the 100-hour inspection is not informal, nor is it solely focused on safety equipment, nor is it scheduled quarterly. Instead, it directly parallels an annual inspection in terms of thoroughness but is specifically triggered by the number of flight hours logged, thus ensuring that the aircraft remains in peak condition for ongoing use.