Peter MacPherson wrote:

Even if the private aircraft is cheaper than the airlines? Was this put in
so
employees weren't chartering G-V's g and not really meant for personal
aircraft that could save them money?

I don't know the reason for the policy. There was a rumour that it was reaction
to a guy who tried to write off his loaded expenses (hangar rent, annual
maintenance, etc.), but I suspect it was simply that they didn't want to
encourage business use of private aircraft for fear of liability issues. If they
had wanted to take steps against overcharging, they could simply have set limits
(such as allowing one to charge the auto mileage rate).

George Patterson
The desire for safety stands against every great and noble enterprise.