Originally Posted by
2Donkeys
Common purpose is a test for the validity of a cost-shared flight advocated by the FAA in a well known legal opinion
It maybe well known to those who have followed that Cardiff player accident thread but I disagree that it is well known. I have held FAA CPL and CFI ratings for nearly 40 years and had never heard of "common purpose" test for cost sharing before reading about it in that accident thread. I have asked other experienced pilots and they had never heard of it either.
Opinions should have no place in defining the rules pilots are expected to know and comply with. If it is a requirement it should be in the regulations.