The maintenance of aircraft is highly regulated, in order to ensure safe and correct functioning during flight. National regulations are coordinated under international standards. Maintenance, repair and operations (MRO) involves fixing any sort of mechanical, plumbing, or electrical device should it become out of order or broken (known as repair, unscheduled, casualty or corrective maintenance).Maintenance tasks, personnel and inspections are all tightly regulated and staff must be licensed for the tasks they carry out.