In an Airworthiness Directive, the phrase 'required within the next 25 hours time-in-service after the effective date' is an example of which type of statement?

• A. Exemption
• B. Reference
• C. Rationale
• D. Compliance

Answer: (D)

The main idea here is a compliance instruction with a deadline. In an Airworthiness Directive, actions that must be taken to address an unsafe condition are specified along with when they must be done. The phrase “required within the next 25 hours time-in-service after the effective date” tells operators exactly what action is needed and the deadline for completing it. That makes it a compliance statement because it imperatively requires action within a defined time frame to remain compliant. It isn’t an exemption (which would waive the requirement for some cases), it isn’t merely a reference to another document, and it isn’t providing the rationale for the requirement. Time-in-service creates the measurable deadline, tied to the directive’s effective date, driving when the required work must be finished.