The following was, in my opinion, almost the best argument they made:
"Based on a study of driving statistics by Hendricks, et al., 1999, approximately 6.4% of driving crashes resulted primarily from driver incapacitations. According to the Aircraft Owners and Pilots Association (AOPA), this type of bill would affect 39,120 pilots. If the same 6.4% incapacitation rate occurs for pilots under driving license medical standards, up to 2,503 new aircraft accidents would occur."
But then I looked at the linked study, where it defines its categories, and found this: "
INCAPACITATION (e.g. fell asleep) - 6.4%"
[EDIT: According to the
study results, the 6.4% is the percentage of drivers contributing to causation, not 6.4% of crashes. In fact the original study says that 2% of driver contributed crashes were due to seizures and blackouts; 4.4% were due to falling asleep. Since driver contributed crashes accounted for 59.7%, the final tally for medical incapacitation as causal for accidents amongst drivers was .597*2 = 1.2%. And contrary to the bogus math used by the AsMA, you DO NOT multiply either 6.4% (or 1.2%) by the number of pilots to determine the increase in accidents. You multiply by the number of past accidents. In fact the number of accidents would increase only by 1.2% (or even 6.4% using their numbers.) An increase of about 15 new accidents a year, of which 3 would be fatal. NOT 2,503. That latter results from confused or deliberately deceptive math by the AsMA - their probability units are wrong.]