In accordance with the mission of AGARD the Structures and Materials Panel (SMP) has always kept an open eye for the possibilities to sponsor collaborative programmes of research. AGARD is unique in its ability to realise the cooperation of laboratories in up to sixteen nations. In this way AGARD distinguishes itself from other international scientific and technical organisations. In the 1970s the SMP decided to embark on collaborative research activities in the area of fatigue. One of the first activities was the Corrosion Fatigue Cooperative Testing Programme (CFCTP), the recursor to the Fatigue in Aircraft Corrosion Testing (FACT) programme. Both programmes are described in this report. Failure by fatigue and degradation by corrosion continue to be major considerations in aircraft design. Environmental effects influence both initiation and propagation of fatigue cracks, and dynamic loading may cause more rapid deterioration of corrosion protection systems. Therefore the conjuoint action of dynamic loading and environmental attack, i.e. corrosion fatigue, requires special attention. Many corrosion fatigue tests have been done on aluminum alloys. However, few included critical structural details like joints, under realistic cyclic load histories and in service-like environments. Even fewer used practical corrosion protection systems. These aspects are specifically addressed bye the CFCTP and FACT programmes. The results provide a significant contribution to the understanding of aircraft corrosion fatigue and should encourage further investigation in this difficult and challenging area of aerospace technology.