MRO World – aircraft maintenance, repair and overhaul

A Maintenance, Repair and Overhaul  (MRO) company performs aircraft repairs at what is termed an FAA repair station. In the US, the FAA provides a list of designated repair stations at Repair stations are located outside US territory as well.  Depending on the the business environment and the needs of an airline carrier, substantial aircraft maintenance may be done entirely in the US, for instance American Airlines, or it  may be outsourced overseas, for example as is done typically by United Airlines, when it outsources some maintenance to Ameco Beijing in China.  Finally, a foreign MRO may have a substantial presence in the continental US, as is the the case with ST Aerospace in Mobile, AL.  ST Aerospace is headquartered in Singapore.

MRO - Ameco Beijing - maintenance,repair and overhaul

Ameco Beijing - a large Chinese MRO

The FAA first put in place foreign repair station regulations in 1949, when more US  aircraft began flying international routes, requiring  maintenance to be performed abroad.  Then, in 1988, there was a change in part 145  FAA regulations governing certification of foreign repair stations, which allowed  greater use of foreign repair stations for aircraft repairs to aircraft registered in the US.  This was a change in FAA regulations, and not an Act of Congress.  Since 1988, the FAA has made attempts to apply part 145 regulations equally to both foreign and domestic repair stations, in an attempt to better regulate all repair stations.  Theoretically, by requiring all US and foreign  MRO repair stations to comply with FAA regulations, a parity in the quality of aircraft maintenance across MRO’s can be achieved.

It is a daunting task to list all the worldwide (MRO) Companies.  Nonetheless, I have found a comprehensive list of  MRO’s worldwide.  This can be found at:

In the US, a comprehensive list of 3,200 companies is available at:

For instance, by looking at the China coverage in,  we see the following as registered MRO shops in China:

  • Ameco Beijing     Beijing
  • Boeing Shanghai Aviation Services Co Ltd     Shanghai
  • Flightparts (Xiamen) Component Services     Zhangzhou
  • GE Engine Services – Xiamen     Xiamen
  • GE On Wing Support – Xiamen     Xiamen
  • Guangzhou Aircraft Maintenance & Engineering Co. Ltd (GAMECO)     Guangzhou
  • Hamilton Sundstrand – Xiamen Repair Station     Fujian
  • Hangxin Aviation Engineering Group – HAEG     Guangzhou
  • Lufthansa Technik Shenzhen     Shenzhen
  • MTU Maintenance Zhuhai Co Ltd     Zhuhai
  • Shanghai Pratt & Whitney Aircraft Engine Maintenance Company     Shanghai
  • Shanghai Technologies Aerospace Company (STARCO)     Shanghai
  • Sichuan Snecma Aero-Engine Maintenance Co. (SSAMC)     Chengdu>
  • Taikoo (Xiamen) Aircraft Engineering Co Ltd     Xiamen
  • TAECO – Taikoo (Xiamen Aircraft Engineering)     Xiamen
  • Volvo Aero Services – Beijing

For example, if you wanted to get a profile on the largest MRO in China,  Ameco Beijing, you merely need to follow the link provided by, and explore their MRO business.

FAA Maintenance Checks and maintenance, repair and overhaul

The FAA mandates several types of airplane maintenance checks, as follows:

  • A Check – performed about every 500 to 800 flight hours. The A Check is usually done overnight at an airport gate
  • B Check – performed about every 3-6 months. The B Check is usually done in 1-3 days at an airport hangar
  • C Check – performed about every 16–21 months or a certain amount of actual Flight Hours  as defined by the airplane manufacturer. This C Check is more complete than a B Check, as pretty much the whole aircraft is inspected in a C Check
  • D Check -  The Heavy Maintenance Visit (HMV). This check occurs approximately every 5–6 years. It is  the most demanding and comprehensive check for an airplane.

The amount of labor involved, and comprehensiveness of a D Check, is staggering. Upwards of 30,000 labor hours may be required. For sure, airlines are under severe pressure to keep the cost of an airplane D Check as low as possible. At times, a cost-benefit analysis may even dictate a functioning airplane is scrapped rather than have it undergo a D Check. The amount of work involved in a D Check is well described at

Some MRO’s are used by airlines when airplanes need to undergo D checks, while the other checks are kept in-house.  A typical MRO maintenance D Check on an aging aircraft is shown in this time lapse movie, showing an Airbus A300 undergoing an extensive maintenance check at Monarch Aircraft Engineering Luton, UK.

Clearly, the maintenance, repair and overhaul industry is filling an aerospace industry need for cost effective aircraft maintenance. It appears poised for robust growth for years to come.

by Steve Adams


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  3. The Red Tail | Says:

    [...] don’t necessarily have to outsource work overseas  to lower labor costs. Instead, many MRO‘s import cheap foreign workers using H1-B visas, and house them in America.  If I was a [...]