Use the Freedom of the Skies and start an international airline operating out of some third world hell hole…. anywhere in the world for a couple hundred bucks… all flights connecting through Timbuktu or Dhaka or where ever.
Lease a couple of long range jets… Airbus A330 ER or Boeing 777 ER so you can cover most of the globe.
Crew the aircraft with nationals and desperate US regional pilots who will sell their children to fly a wide body jet. Hire locals for support staff for next to nothing.
Do maintenance third party in another third world place.
Sit quietly and watch the money roll in.. while you significantly under cut airlines who are doing the same sort of thing in much more expensive places like Emirates.
Robert Crandall, former CEO of American Airlines said if you want to be a millionaire, start with a billion dollars and run an airline.
But China and India are areas where travel is growing really quickly.
Start with a huge fortune!
From that point on, the airline business is the easiest way to end up with a small fortune!
Pole to Pole Airlines, with direct service between the North Pole and the South Pole. Never been done before.
Find a third world country that has a mining/drilling boom about to begin.
Grease local land owners/politicians/guerrillas/etc. (So you don't end up hanging from a tree or having your head fall off).
Build an airfield. Build hanger/maintenance facility. Bring in gas.
Run flights to nearest international airport.