I remember someone posted on here that the CAA granted a special exception, a "ceremonial" flame clause.
Here is the quote:
Originally Posted by
FlyMeAwayPlease
On BA's Facebook page:
"The flame is not extinguished during the flight. It has been classified as a 'ceremonial flame' by the Civil Aviation Authority, and they have given us permission to transport it whilst still alight. The Torch will be kept in a Davy lamp in a special cradle strapped to a seat. It has got enough smoke-free fuel to keep it going during the flight."
Perhaps it's me, but I find that geekily interesting and wasn't aware of that!