Darrel Toepfer wrote:

I quoted wrong, full tanks yields 411 pounds useful inside the cabin,
537 lbs total (front baggage? 100# max)...

So. Using the figures you provided, you can put 60 gallons in the tanks and do 3
hour legs with nearly 45 minutes reserve and carry 663 pounds in the cabin (789
max). That's a little better, but not much. Leave the de-ice tanks empty, and
you get another 40 pounds. That finally gets you up to 4 FAA adults.

George Patterson
Give a person a fish and you feed him for a day; teach a person to
use the Internet and he won't bother you for weeks.