I take my mother on holiday every year. She is in her late 70's and has multiple health problems. This year we are thinking of a cruise to New York, a few days there, and then flying back. I will check with her doctor before we book, but I want to know if aircraft carry defibrillators, as I am concerned about the lack of medical facilities whilst in the air? Lisa Jeffreys, Bingley

Sunday Times travel expert, Richard Green, responds: Airlines aren't legally required to carry defibrillators, but many do, including British Airways and Virgin Atlantic.

Cabin crews are given first aid training and there are onboard medical kits, including defibrillators, which can be used in the event of cardiac arrest.

About 80 or so airlines, including BA and Virgin, also use a clever back up service called MedLink. This puts the crew in touch, via a satellite phone, with a physician on land, who is specially trained on the illness and remedies inflight and can give real-time advice to the crew, or another health professional onboard. The Medlink team also assists airline captains in deciding whether to divert and, if so, which of the available diversion airfields has the most appropriate medical facilities.

The term "Good Samaritan" is used to describe any doctor or nurse who responds to the cliché call "is there a doctor onboard?". Airlines will usually indemnify liability that might arise from their assistance in an emergency, and by the way, it's a myth that no doctor will give ad hoc help in the States for fear of being sued afterwards. In fact, the US has specific legislation to protect people who come forward in such circumstances.

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