Or we could try an alternate explanation: because those who are lucky enough to live through the ordeal aren't usually stupid enough to go blabbing about it and those who are dead aren't normally prosecuted for obviously reasons?Research enforcement actions, case law, legal opinions and precedence for evidence to support your claim and you'll come up empty.
Except violate the regulations against purposefully or negligently hazarding ones aircraft? Do a search for reckless flying and you'll find plenty of cases of people being charged for doing stupid things with aircraft at the federal, state and local level. This jerk-off comes to mind: http://www.smmirror.com/articles/New...robation/34992 Flying headlong into a thunderstorm itself might not be specifically illegal but the sort of flying most rational folks would lump it into is enough to get one's license yanked and apparently land your butt in jail. That is, as mentioned before, you're lucky enough to escape such brazen stupidity with your life. It doesn't have to be specifically spelled out because only the "lowest denominator" would fail to realize that a broad "don't do things that endanger yourself, your aircraft or anyone on the ground" regulation (for example FAR Part 91.13) wouldn't apply to flying into known convective activity in an airplane that is most of the time going to break if you do so. Since Part 91.13 states endangering others specifically, I will point out that the case involved the pilot flying with a passenger on board (refer to http://www.ntsb.gov/aviationquery/br...26X35112&key=1 ). A reasonable person would look at a flight through a convective cell or line and go "Yup, that's willfully endangering the life of another person" and ergo, violation of Part 91.13 and probably several other subsections of the FAR as well.The accident pilot did nothing illegal.
Flying in severe weather can be planned and executed with less risk than a 50 hr pilot faces when landing with a crosswind.
The bigger question is "Why would you do it in the first place?".