 Most sectors of GA for which data are available have experienced growth in aircraft numbers and hours flown over the last two decades . The lighter end of the GA spectrum : microlights , amateur built , and airships and balloons , have in particular shown strong growth , although the last of these activities was severely curtailed during the foot @-@ and @-@ mouth outbreak in 2001 , when access to farmland was denied . After strong growth in the late 1980s , traditional flying has shown a slight decline recently , reflecting a move amongst recreational <unk> towards microlight aircraft , and increased numbers of foreign @-@ registered aircraft . Recreational helicopter usage has grown primarily due to the introduction of smaller and cheaper aircraft . <unk> activity has remained relatively static , although there has been a gradual increase in the number of self @-@ launching motor gliders . 
