A south Wales man who calls himself the "Flying Vet" is being held in a psychiatric unit after landing near President George W Bush's Texan ranch.
Maurice Kirk, 62, from St Donats, Vale of Glamorgan, was arrested after he put his plane down on private land seven miles from the Crawford ranch.
His website claims he wanted to thank Mr Bush for his rescue by the US coastguard after ditching in the sea.
His wife said he was being held in handcuffs and he was "very rattled".
McLennan County chief deputy sheriff Randy Plemons said Mr Kirk would be questioned once he was released from hospital in state capital Austin.
He said Mr Kirk - who was struck off as a vet six years ago - was originally held for being drunk but was then taken straight to the psychiatric unit.
Mr Plemons said the pilot was talking to him about his flying experiences - including landing in shark-infested waters off the Dominican Republic in February - when he was arrested at about 5pm local time on Friday.
Mr Kirk began an attempt to fly solo around the world in 2001.
A former drinking friend of the late actor Oliver Reed, he was expelled by the Royal College of Veterinary Surgeons in 2002 for "disgraceful" conduct after he chalked up a string of court appearances.
Two months ago the United States Coast Guard praised his decision to take an emergency radio beacon with him when flying past the Dominican Republic as he had to ditch in the Atlantic ocean 75 miles (120 km) out to sea.
The authorities in McLennan County said Mr Kirk's plane remained in the field and would be looked at by experts when the weather improved.
Mr Kirk's wife Kirstie made two postings on his website on Monday, and in the first said her husband was "required to have a psychiatric assessment before secret services (CIA or FBI) question him further".
On the second, she wrote: "He is [very] worried about the little aircraft as he heard bad weather last night and just hopes that it was tied down as he requested".
Referring to the no-fly zone around President Bush's ranch, she wrote: "I understand that he did not fly within the prohibited flight area, and so hope that this difficulty can be resolved quickly, not least because he is due home on 1 May and it's his turn to do the washing-up."