I treated a lady having a heart attack several years back whilst travelling to the USA. There was no doctor or nurse on board - at least none that made their presence known.
Virgin had an excellent range of equipment and drugs available for the medics' use. I also queried the liabilty situation as the patient was American. Virgin's insurance policy covered me up to my level of training or anything done under direct direction from (?)Medlink.
You are also covered by the law of the country where the aircraft is registered.
I was also contacted later by Virgin's medical advisors for my views and opinions on the equipment they supplied.
The champers and hamper was quite nice too!
PW