I am a South African national currently visiting the US and flying through Heathrow on the way back to South Africa. I have a long layover in Heathrow, but I fly in and fly out on the same day.
I am submitting a request to extend my stay in the USA. When I leave I will have been in the USA for just over 7months. I have a valid USA visa and will be passing through Heathrow, 12 hr layover.
Am I right in understanding that I would not have needed a DATV because I have a USA visa and am transiting UK on the way back from USA to my country, IF I WAS PASSING THROUGH UK WITHIN 6 MONTHS OF LANDING IN USA? I will have been in the USA for 7months due to an extension on my visa. Does this mean that I will need a DATV? It is not clear to me.
In either case, having a direct airside transit visa or not having a visa, can I leave Heathrow on my twelve hr transit or must I remain in the airport?
Thank you for your information.