The head of Boeing Commercial Airplanes, Stephanie Pope, met the chairman of Air India on Monday in India, two sources said, as the companies seek to find the cause of last week's fatal crash involving a Boeing 787 Dreamliner.

In 2012 a Boeing jet was deliberately crashed in the Sonaran desert, Mexico and filmed it for television. The test revealed the safest seat to sit in.

There have been cases of a very small number of survivors in very serious accidents, but it is "very rare" for there to be only one, a professor told Newsweek.