DaveTanya

http://www.staralliance.com/en/services/visa-and-health/#

This is what I found when I booked the flight.

I will let her know thanks

She is landing in Heathrow and changing airports to Gatwick. I just called Gatwick and they said no problem it's standard procedure to grant 24 hour access as long as she has her ticket showing she is leaving within 24 hours. So yes she will be leaving from Gatwick to go to Mexico.

I called the Heathrow airport and they said she does not need a transit visa as long as she has the tickets showing she is leaving the airport(country) within 24 hours. Even though she has to change airports.

My Russian girlfriend wants to travel to Cancun and meet me there. The flight goes through London. She is required to change airports there. Does she need a transit visa? And is this common? I am worried for her. She will also need to use the airport hotel.

Yes again, is it allowed for a Russian girl who would not normally be allowed in the states for a tourist/travel visa to use an airport (say Miami) for a stop to the Dominican Republic?