Re: So what happened?
As per DS's suggestion - "Just require *them* to be passengers".
Some execs might be cold hearted ruthless bastards who wouldn't think twice about putting their partners, children etc. at risk if the payoff for a successful test was a bigger bonus cheque at the end of the year, but if you enforce requirement for them to put their *own* lives on the line, rather than allowing them to delegate the responsibility to anyone else (even their closest family members as per JSG), then maybe it would make a difference...