What is MRO?

MRO (maintenance, repair, and overhaul) is used to describe the set of operations and activities that are associated with the upkeep of an aircraft which can include the physical maintenance of the aircraft, the systems that operate within the aircraft, and the equipment used to produce the aircraft.

What are MRO Categories?

Within the aviation MRO industry, there are many categories describing the work within aviation maintenance, repair, and overhaul. Some are self-explanatory and some are not. We’ve listed separate MRO industries categories below, highlighting those that are often more confusing. You’ll also find example companies listed within each category. We hope this is helpful.

1. MRO Advanced Materials & Composites

This MRO category deals with composite materials such as carbon fiber, epoxy, polyester resin, and vinyl ester resin, an area of increased importance in the airline industry. Because advanced materials and composites are both lightweight and strong, many are replacing metal components in aerospace, where a product’s weight is critical, so MRO companies in this category are more important than ever.

Companies in this category:

 

2. MRO AIRFRAMES

These are companies that do maintenance, repairs, operations, modifications, and inspections of airframes. These structure and mechanical component services include those to the fuselage, booms, nacelles, cowlings, fairings, airfoil surfaces (including rotors but excluding propellers and rotating airfoils of engines), and landing gear of an aircraft and their accessories and controls.

Companies in this category:

 

3. MRO AIRPORT EQUIPMENT & SERVICES

Airport Equipment Services companies manage or service the tools and equipment that help an airport run effectively, safely, and smoothly.

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4. MRO ASSET MANAGEMENT

Airplanes are expensive. In 2021, Boeing planes ranged from $89.1 million to $442.2 million to build. Aircraft asset management companies help make those planes last as long as possible, from initial acquisition to final disposition. They do this through a carefully planned way of proactively managing the parts, services, and costs of maintaining aircraft.

Companies in this category:

 

5. MRO AVIONICS & INSTRUMENTS

In this category of MRO avionics and instruments are companies that service the electronic systems used on aircraft, artificial satellites, and spacecraft. That’s just as important as it sounds! These systems include communications, navigation, the display and management of multiple systems, and the hundreds of systems that are fitted to aircraft to perform individual functions[1]. Within instruments, you can find companies that build or service three basic kinds of aerospace and aviation instruments: flight instruments, engine instruments, and navigation instruments.

Companies in this category:

 

6. MRO CABIN INTERIORS & INFLIGHT ENTERTAINMENT

The interior of a plane takes careful planning and both high-tech and material solutions. Companies in this MRO category might do anything from repairing seat fabric to rewiring business class for better Wi-Fi. Inflight entertainment deals with the digital systems that keep us all happily listening to music, playing games, or watching movies during a flight, for example.

Companies in this category:

 

7. MRO CALIBRATION & WEIGHING SERVICES

Calibration companies make sure aviation maintenance professionals are able to undertake regular checking of equipment and precision tools used to certify an aircraft or component. This ensures that every piece of equipment is accurate, safe, and compliant with all regulations. Weighing services are also extremely important as the incorrect weighing of aircraft can have major safety implications.

Companies in this category:

 

8. MRO CHEMICALS

In aviation MRO, providers require a wide range of chemicals and consumables for their operations. Companies in this category work in aviation with products that could include oils, greases, sealants, lubricants, adhesives, cleaning agents, paints, coatings, and tapes.

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9. MRO CLEANING

Cleaning encompasses both interior and exterior of an aircraft. MRO cleaning companies could specialize in one or the other, or, in the example of aviation detailing, both. For example, an interior-focused company could focus on cleaning and restocking the interior areas of a commercial aircraft between flights.

Companies in this category:

 

10. MRO COMPONENTS

MRO companies in this category work on the five main components of an aircraft. Those are:

  • Fuselage: The long hollow tube that holds passengers and cargo, also known as the body of the airplane.
  • Wings: Also known as the foils, the wings generate the lifting force needed for flight.
  • Empennage: The tail of the aircraft, which helps with stability using assistance from the rudder and elevator.
  • Power plant: The engine and propeller
  • Landing gear: Shock absorbers and wheels.

Companies in this category:

 

11. MRO CONNECTORS & FASTENERS

The connectors segment of MRO includes maintenance, repair, and operations associated with printed circuit board (PCB) connectors, fiber optic connectors, high power connectors, high-speed connectors, RF connectors, and others. The fasteners category involves different products, such as nuts & bolts, screws, rivets, and more.

Companies in this category:

 

12. MRO CONSULTING SERVICES

Aviation consultants offer invaluable assistance to aircraft owners through various services. Those range from engineering and design to crew certifications. In a highly regulated and complex industry, these services are indispensable to aviation companies as they navigate Federal Aviation Association (FAA) requirements.

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13. MRO ECONOMIC DEVELOPMENT

American States spend billions of dollars every year on economic development activities and aviation brings big money to local and state economies. Within this MRO category, companies focusing on economic development support existing businesses, encourage entrepreneurship, recruit new businesses, and coordinate the economic development activities.

Companies in this category:

 

14. MRO ENGINEERING

MRO engineers bring specific expertise to the industry. They can work with companies to do things like review processes, conduct data analytics, define practical application of technology advances like 3D scanning, recommend continuous improvement initiatives, and pinpoint issues that impact supply chain productivity. This can include the services of a Designated Engineering Representative (DER). This person holds an engineering degree or equivalent, possesses technical knowledge and experience, and works to approve or recommend approval of technical data to the FAA.

Companies in this category:

 

15. MRO ENGINES

Maintenance, repair, and operations is a key activity in the lifecycle of an aircraft and its engines. Companies in this category help to maintain these systems in a safe and functional condition so they can last as long as possible in a safe condition.

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16. MRO ENVIRONMENTAL SERVICES/GREEN

Per the FAA, airport environmental programs help airports implement the National Environmental Policy Act (NEPA) and other federal environmental laws and regulations. This includes airport noise compatibility planning, airport noise and access restrictions, and environmental review for airport development.

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17. MRO FUEL & LUBRICANTS

Within aviation MRO, this category encompasses companies that manufacture fuel and lubricants, distribute them, or offer services for fuel systems and related systems. For example, Exxon Mobil manufactures, Bauer provides testing equipment for fuel, lubrication, etc., and Aviation Fuel Systems Repair specializes in fuel leak detection, repair, and more.

Companies in this category:

 

18. MRO GROUND SUPPORT EQUIPMENT

MRO companies that specialize in ground support equipment (GSE) work with airport support equipment, often found on the servicing area by the terminal, an area called the apron. This equipment does the important work of servicing aircraft between flights in areas like ground power operations, aircraft mobility, and cargo/passenger loading operations.

Companies in this category:

 

19. MRO HANGARS & EQUIPMENT

Aviation hangars protect some of the most complex and valuable machines that any company or person may own. As such, hangar and equipment MRO companies do critical work with long-term consequences.

Companies in this category:

 

20. MRO HARDWARE

They might be small in size, but the importance of hardware can’t be overstated. Aircraft hardware is the term used to describe the various types of fasteners and miscellaneous small items used in the manufacture and repair of aircraft. These parts are small and mighty: the safe and capable operation of any aircraft is heavily dependent upon aircraft hardware that is correctly selected and installed. They can include bolts, nuts, washers, screws, cotter pins & safety wire, rivets, turnlock fasteners, control cable hardware, fluid lines & fittings, electrical wire & connectors, and miscellaneous items like o-rings and crush washers.

Companies in this category:

 

21. MRO HEAT COATING & BRAZING

Thermal barrier coatings (TBC) are a critical part of aviation. It involves work with advanced materials systems that are typically applied to metallic surfaces operating at elevated temperatures as a form of exhaust heat management. These surfaces could be on gas turbine or aero-engine parts and the coatings insulate components from large and prolonged heat loads and can sustain an appreciable temperature difference between the load-bearing alloys and the coating surface.

Brazing is the process of joining two independent pieces of metal to form one strong joint. It is similar to welding but requires less heat and can be used to join metals that may be damaged by high heat. But because the strength of a brazed joint is not as great as that of a welded joint, brazing is not used for critical structural repairs on aircraft or for any metal part that received sustained high temperatures.

Companies in this category:

 

22. MRO HYDRAULICS & PNEUMATICS

In modern aircraft, many critical components use hydraulic systems. Those areas include cargo doors, nose wheel steering, spoilers, rudders, landing gear, flight controls, and flap/slat drives. These aviation hydraulic systems offer many benefits, being cost-effective, easy to maintain, and operating efficiently in the demanding conditions of flight. Pneumatic systems are less common but operate a great deal like hydraulic systems. The difference is they use air instead of a liquid for transmitting power. You might find pneumatic systems used for brakes, opening and closing doors, operating emergency devices and driving hydraulic pumps, alternators, starters, water injection pumps, etc.

Companies in this category:

 

23. MRO LANDING GEAR, WHEELS, AND BRAKES

This category is somewhat self-explanatory, as these companies assist in the maintenance, repair, and operations of aviation landing gear, wheels, and brakes. Their work is critical as it gets planes and people safely off the ground and back down again.

Companies in this category:

 

24. MRO LEASING & FINANCIAL SERVICES

Not everyone who flies a plane buys it outright. MRO companies in this category are involved in the leasing and lending side of aviation.

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25. MRO LIGHTING

This category isn’t just about safety-certified aircraft interior and exterior lighting systems for planes. It also encompasses airport heliport and runway lighting, obstruction lighting products, and other airport lighting products.

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26. MRO MANUALS, REPAIR DOCUMENTATION & RECORDS

As a highly regulated industry, aviation professionals must comply with the documentation requirements of the FAA, as well as those of individual companies. This ranges from manuals that explain how something works to the necessary repair documentation and records that must be kept for specific periods of time and be available for inspection by regulators if needed.

Companies in this category:

 

27. MRO METALS

Within aviation MRO, these are companies that broadly deal with the fabrication and manufacture of metal parts.

Companies in this category:

 

28. MRO MILITARY MAINTENANCE

This category is one of the largest parts of MRO. Companies in military maintenance service a wide variety of aircraft and often have massive spaces to properly and efficiently repair and inspect everything from cargo planes to helicopters.

Companies in this category:

 

29. MRO PAINTING & COATINGS

The way an aircraft looks comes from the expertise of the aircraft painting and coatings part of the aviation industry and can include everything from a work of art on the aircraft to brand logos. Paintings and coatings must be able to withstand a variety of challenging weather and atmospheric conditions, so there is advanced t­echnology involved in this category.

Aerospace coating can also be called aircraft coating, aviation coating, or aircraft paint. The aircraft’s production, repair, and maintenance team make use of specialized aviation paints to extend the life of aircraft structures and prevent corrosion. It’s an essential part of taking care of a plane.

Companies in this category:

 

30. MRO PARTS DISTRIBUTORS

Maintenance, repair, and operations parts cover the gamut from upkeep supplies to plane parts themselves. These MRO distributors get the right part to the right place at the right time.

Companies in this category:

 

31. MRO PARTS MANUFACTURER

These companies make the parts that keep the industry moving smoothly and planes safely in the air.

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32. MRO RECRUITMENT & PERSONNEL

The knowledge and skills of aviation professionals represent the fuel that drives the engine of business. Recruiting and keeping talented employees on board is a job in itself and MRO companies in this category help make that happen.

Companies in this category:

 

33. MRO SAFETY & EMERGENCY EQUIPMENT

The FAA’s safety mission requires it to take action to reduce or eliminate the possibility or recurrence of accidents in air transportation. The FAA and the air transportation industry have sought innovative means for addressing safety problems and identifying potential safety hazards. Companies in this MRO category make that happen by working with FAA-mandated equipment, including life preservers, oxygen masks, emergency slides, safety belts, fire detectors, survivor locator lights, and more.

Companies in this category:

 

34. MRO SOFTWARE

As the aviation industry moves toward greater and greater automation of almost all areas, software often drives increased accuracy, savings, service, and customer satisfaction.

Companies in this category:

 

35. MRO SUPPLY CHAIN & LOGISTICS

A supply chain is a network between a company and its suppliers to produce and distribute a specific product to the final buyer. MRO companies in this category might work along any point of the supply chain, including automation, which manages an optimized inventory and often leads to increased accuracy, performance, and savings.

Companies in this category:

 

36. MRO TEST EQUIPMENT

Avionics test equipment is used to support the development, manufacture, test and maintenance of commercial, private, and military airborne electronic systems.

Companies in this category:

 

37. MRO THIRD-PARTY MAINTENANCE

The care and maintenance of aircraft plays a vital role in its safety and longevity. It is also a costly part of ownership, so many people choose third-party MRO providers instead of creating an in-house department. Third-party companies can often drive better profitability and management to drive down cost and improve quality.

Companies in this category:

 

38. MRO TOOLS

Engineering and aviation maintenance professionals use many tools to service, repair, overhaul, and maintain the huge range of aircraft in the air today by checking fixtures and performing repairs on structures, components, and equipment. The companies in this MRO category work with tools that could be simple and commonly found in a home toolbox or specialized and unique to aircraft maintenance. Their work ensures an aircraft’s structural soundness.

Companies in this category:

 

39. MRO TRAINING

Training within aviation MRO is a broad category for education and training related to all manner of subjects. That could be airport management, ground staff and cabin crew training, commercial pilot licensure, aviation hospitality, and so much more, including safety and management.

Companies in this category:

[1] https://en.wikipedia.org/wiki/Avionics