In 1982, I began working for Federal Express; it had brand new 727 aircraft to build up its domestic service. Within 30 months it’s using those 727 aircraft for European flights before transitioning to DC-10s. FedEx, like many others, was expanding internationally. By 1992, you could count on one hand the major airlines that stuck strictly to domestic routes.

But the effects of international aviation weren’t limited to airlines; Boeing, Cessna, and Bell began sharing the stage with international competition. As U.S. manufacturers brought in work to their fixed-wing and rotorcraft products, so did repair stations specializing in component repair both here for foreign manufactured components and across the borders and oceans for U.S. manufactured components; Part 145 repair stations that provided anything from brake assembly overhauls to instrumentation repairs were breaking from the mom-and-pop repair stations of the past.

As international travel expanded it became more efficient to perform phase checks on foreign soil; an aircraft committed to an overseas route could receive scheduled checks across the pond rather than drag the aircraft back home, thus eating up flight hours and cycles. In these foreign markets, repair stations provided a market for U.S. operated businesses by opening in foreign countries and becoming a new source of convenience providing phase checks, repairs, alterations, modifications, and on-site component overhaul. No matter where one stands on the issue of maintenance accomplished overseas, it’s here to stay.

Maintenance implementation procedures

Let’s speak about maintenance implementation procedures (MIP) under the bilateral aviation safety agreements (BASA) provisions; we’ll reference FAA Order 8000.85A, which speaks to establishing a MIP. According to Advisory Circular 21-23B, a BASA is “a government to government agreement, consisting of one executive agreement and one or more maintenance implementation procedure, to facilitate the recognition of procedures for the mutual acceptance of” different approvals related to environmental, airworthiness, and/or operations; they replace bilateral airworthiness agreements. Simply, the BASA is the handshake between two countries agreeing to Part 145 repair stations being allowed to operate in the other’s country.

The BASA specifically provides for joint participation in the inspection of civil aviation authorities and undertakings, for cooperation and assistance in any investigation or enforcement proceeding, and on the exchange of safety data, including data on accidents and incidents. BASA also foresees mutual recognition of aviation safety certificates obtained through shortened product approval procedures and joint acceptance of product tests.

No country gives free rein to another to act with impunity on its regulated stuff. A MIP is “the procedural document authorized by the BASA executive agreement related to the performance of maintenance, alterations, and modifications on civil aeronautical products.” A technical implementation agreement between the FAA and a country’s national aviation authority (NAA), the MIP defines procedures to accept each authority’s recommendations for repair stations surveillance. Aircraft certification also has implementation procedures with its own set of procedures for e.g. recognition of manufacturing certification. To clarify: MIPs are written arrangements two countries have to assure rules compliance; both countries agree on how to keep an eye on repair stations.

National aviation authority

A national aviation authority is a country’s regulatory agency, as the FAA regulates for the United States; NAAs are specific to each country, e.g. for the United Kingdom, it’s the Civil Aviation Authority. Also, the FAA recognizes that certain sections of the maintenance rules are international standards; since the FAA belongs to the International Civil Aviation Organization (ICAO), it requires, per ICAO, to have: appropriate tooling, equipment, technical data, and both trained and qualified personnel.

Once a MIP is concluded, the NAA and the FAA can decide if a repair station receives initial certification, renewal with all ratings, any amendments to a repair station’s certificate, or even if the repair station is denied renewal. Additionally there will be a “reciprocal acceptance of recommendations for certification and renewal” and recording of results from surveillance when a NAA issues certificates to U.S.-based repair stations. And when the NAA refuses certification of a U.S.-based repair station, the FAA, per the MIP, accepts NAA findings and recommendations for renewal and certification.

Foreign repair stations

The FAA certifies nondomestic repair stations operating under the provisions of Title 14 CFR Part 145; these foreign repair stations maintain, modify, or alter aeronautical products per U.S. airworthiness regulations. Under each MIP, a NAA and the FAA coordinate efforts to develop procedures for surveillance, schedules for inspection, and certification programs. These international agreements allow the oversight door to swing both ways. The NAA oversees the foreign repair stations per the standards of that country, and the FAA oversees its repair stations located here as per our standards. The two countries’ married policies per MIP guarantee that the repair stations in any country are receiving harmonized oversight.

To conclude a MIP, the FAA follows a four-phased process together with NAAs with a BASA (if the NAA lacks a BASA, one is negotiated while the MIP is being concluded). First the FAA familiarizes itself with the NAA system, assuring it has proper documentation and sufficient capability.

A FAA MIP team is gathered to evaluate the NAA system in the second phase; here regulations are checked for compatibility while joint assessments of the NAA’s repair stations take place. In the third phase the MIP is developed; the FAA and NAA discuss differences and special conditions. In the final fourth phase, the U.S. State Department concurs with the MIP and the FAA/NAA sign off on it.

Note: Some long-standing working relationships between the FAA and some countries or regions could result in limited joint assessment inspections. The European Aviation Safety Agency (EASA) and its forerunner the Joint Aviation Authority (JAA) have this kind of relationship, so assessment inspections between the two may not be necessary.

A MIP issued by the FAA and NAA for a particular repair station is based on evaluations of 14 CFR Part 145 and foreign NAA regulations ruling repair stations. The joint evaluation streamlines the surveillance of the repair station to eliminate redundant criteria and identify differences; the resulting regulations and requirements are used to conduct surveillance on the repair stations either by the FAA or NAA, according to where the repair station is located. The evaluation also determines the ability for the FAA or NAA to carry out surveillance on the other’s behalf; in other words there will be surveillance by one qualified overseer instead of two or three while maintaining equivalent levels of safety.

If there’s no BASA

But suppose a repair station in a foreign country or within the United States isn’t operating under a BASA and its related MIP; what standards does it work under? The repair station is subject to perform work on aeronautical products to FAA standards and one or more different NAA standards. The ends are the same — the repair stations must meet the standards of both entities.

What’s the benefit of a MIP? It’s like going through two security screening stations in a row at the airport; the second station says put your shoes back on but take your socks off first. The rules the repair stations must follow with a MIP result in synchronized safety systems with less cumbersome/costly technical and administrative procedures for the recognition of certificates.

It’s difficult to list the BASA countries here, but they’re worldwide and the list changes frequently. International agreements are vital; the BASA/MIP is the surest way the FAA has for maintaining safety across the globe. 


Stephen Carbone is an aviation industry veteran of 28 years. He works at the Boston regional office in the Flight Standards Airworthiness Technical Branch. He holds a master’s degree in aviation safety systems.