Depends BigDH....If you are in the wrong aircraft at the wrong time at the peak of the solar cycle, in the vicinity of a coronal mass ejection (such as that has just reached the earth) you could get around 100 times your annual dose in one flight. Sounds nasty to me. What concerns me is that Big Airways flight planning department had no idea of this event, and yet under European law , it is a requirement for them to monitor each crew members annual radiation exposure AND act on such warnings. Sounds like Big company syndrome to me.