Over the past six years, the CAA has noted a significant increase in the number of amateur-built balloons on the UK register and there are now several large envelopes, capable of carrying at least four people. Unlike other amateur-built types capable of carrying multiple people, amateur-built balloons and airships are not currently regulated with respect to airworthiness.
While amateur-built balloons and airships remained small in both size and quantity, the CAA did not see the need to consider airworthiness regulation for them. However, the recent increase in the quantity of multi-occupancy amateur-built balloons has caused the CAA to re-evaluate this national policy. The CAA has sought a balance between safety and operational freedom in developing this policy and has considered the amateur-built balloons and airships currently on the UK register. Working in conjunction with the British Balloon and Airship Club (BBAC), the CAA has developed SD–2021/004 to limit the envelope size and number of occupants in amateur-built balloons and airships until such time as a collaborative working group determines whether an airworthiness assurance system is required.