In the 1970s, a few major European National Aviation Authorities started to join activities and founded the Joint Aviation Authorities (JAA), with the objective of a cooperative safety regulatory system to achieve uniform high standards of aviation safety. At the same time, the JAA would play a role as the European counterpart of the US Federal Aviation Administration (FAA).
In the following years, both organisations worked closely together in harmonizing rules and regulations where possible, while Bilateral Agreements were signed with other Aviation Authorities, like Transport Canada.

In August 1991 JAA based their headquarters in Hoofddorp, the Netherlands, and more and more European National Aviation Authorities (NAA) became a JAA Member State. However, the rules and regulations recommended for adoption by JAA were not mandatory and each JAA-NAA could still keep their national legislation when preferred.

A new framework for aviation safety in Europe, created by the adoption of EC Regulation 1592/2002 (Basic Regulation) of 15 July 2002 on common rules in the field of civil aviation, led to the establishment of the European Aviation Safety Agency (EASA), whose adopted rules and regulations are mandatory for each Member State.

As a consequence, as of autumn 2003 JAA’s rulemaking activities were gradually transferred to EASA, while the upcoming close-down of the former JAA-system was processed by means of a transition phase.
JAA was transferred into JAA-T (“Transition”) consisting of a Liaison Office (JAA LO) located in EASA premises in Cologne (Germany) and a Training Organisation (JAA TO) in Hoofddorp (Netherlands). JAA LO assisted the non-EASA JAA Member States and supported EASA in the transition process, while JAA TO concentrated on - and expanded - training activities.

With the publication of the revised EC Regulation 1592/2002 on 19 of March 2008, EASA took over all responsibilities which were previously in the hands of JAA.
At the ECAC Directors General meeting of 19 March 2008, it was decided that the JAA Liaison Office in Cologne would be disbanded by 30 June 2009, whereas the JAA Training Organisation would continue its activities in the legal form of a Dutch Foundation and as an associate body of ECAC.

Paris, 20 January 2009: the "Arrangements between ECAC and JAA TO" were signed, establishing JAA TO as an associate body of ECAC!