@Peter says above:
I wonder if @howard has any idea as to what this may be about.
My knowledge of VAT is generally patchy (it’s not my specialist field) but three of my colleagues are extraordinary VAT specialists. That’s all they do. However, there is also a rarified and very narrow VAT specialism that deals solely with boats and planes, and I don’t know if my colleagues have such expertise. I do know (as many here do) that there were lots of schemes around a few years ago relating to importing boats and planes in a way that could avoid VAT. Most of those loopholes were closed once they became generally known, others were considered questionable at the time and were attacked through the courts. As to the effect of a hard Brexit on planes in particular, I have no knowledge. If anyone has a serious professional interest in such matters they can hunt me down at work and I’ll gladly introduce them to one of my firm’s VAT experts.
I’m sorry that I can’t offer any practical help. The press reports (I’m sure correctly) that even in a hard Brexit there will be a number of small and important deals done, and I heard Boris refer to one relating to aviation earlier today. (Others for instance relate to nuclear power and information sharing relating to terrorism.) So we might later learn that flying our little planes between the EU and the UK won’t give rise to unexpected VAT liabilities even after the UK has sailed strongly away from the continent with a bucket load of false pride, and with its chest puffed out whilst singing Rule Britannia!