Don't wander off in the weeds Hank... I have run my own businesses all my
life, and my accountant can cite chapter and verse of tax court rulings, and
yes I expense my airplane for those trips that are business... If you are
disguising vacation, personal, and fun travel, as a business expense -
regardless of the mode of transport airplane/boat/car/train/oxcart - it will
be denied when discovered, and rightly so...

That is not what Judge Hand ruled on... He ruled that the federal
government does not have the power to force you to arrange your affairs to
maximize the amount the government can tax you... By corollary, the
government cannot increase your tax burden because you choose to buy your
copy machine toner from a distributor that is 10% more than some other
distributor, or force you to ship your employees by Greyhound because they
are cheaper than the airlines... Such a ruling would create chaos for the
business community, and bring down the current tax law in the end - not
necessarily a bad thing...

Dow Chemical Corporation's flight department is just up the road from me...
I am on speaking terms with a number of their senior pilots and
executives... I have talked about this issue with them... It costs them more
to operate the airplanes than it would to ship their people by commercial
coach fares, especially given the volume discounts they could arrange, BUT
their people, many of whom fly 2 or 3 days a week continuously, would lose
far more hours waiting on airline schedules, etc... Their people are more
productive because Dow runs a tight schedule with it's own airplanes... The
irs has not even tried to challenge Dow's use of it's planes... Needless to
say, Dow has iron clad rules for who gets on their airplanes... Momma and
the kids don't go to Orlando with you...
denny

"Hank Rausch" wrote in Here is a relevant
passage from tax law: