If a category B item was reported at 9:15 on March 17th, when does the aircraft become unairworthy?

In aviation maintenance, a Category B item typically refers to a discrepancy noted in an aircraft's maintenance records that requires action, but has a specified period in which the airline can address it before the aircraft becomes unairworthy. For Category B items, the regulatory guidelines generally specify a 72-hour window to rectify the issue.

Given that the reported time is 9:15 on March 17th, adding 72 hours would lead to unairworthiness at 9:15 on March 20th. This timing reflects the need for immediate attention to the item noted, and after this grace period has expired without resolution, the aircraft would officially be considered unairworthy until the issue is addressed.

Understanding the timeline and regulations that govern maintenance discrepancies helps in managing aircraft safety and compliance effectively.