What type of inspections does the MRC-390 refer to?

The MRC-390 refers specifically to Conditional Inspections. This type of inspection is conducted to assess the condition and operational capability of a system or component when certain conditions warrant it, rather than following a strict schedule. It is typically requested when there are indications of potential deficiencies or when performance issues arise that could affect the reliability of the system being inspected.

In contrast, routine inspections are performed at regular intervals to ensure ongoing compliance and operational effectiveness, initial inspections focus on new systems or components prior to their introduction into service, and annual inspections are conducted on a yearly basis to maintain oversight of equipment or systems. The distinction here emphasizes that Conditional Inspections are reactive and based on specific situations, which aligns with the purpose of the MRC-390.