Maintenance Repair & Overhaul | MRO

Maintenance Repair & Overhaul or MRO refers to aeronautical maintenance activities delivered by approved actors specific to this sector. They form a set of strictly regulated, mandatory maintenance cycles, generally divided into 4 categories:


  • Level A maintenance: to be performed monthly.
  • Level B maintenance: to be performed every 3 months.
  • Level C maintenance: to be performed every 12-18 months.
  • Level D maintenance: to be done every 4-5 years.


The Maintenance Repair and Overhaul activities include track maintenance, main structure maintenance, engine maintenance, and maintenance of components and equipment.



Related definitions

Maintenance in Operational Condition | MCO Maintenance Time To Repair | MTTR Maintenance Time Between Failure | MTBF Reliability Availability Maintenability | RAM