Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding. Using a text editor, edit the "aircraft.cfg" file in folder named after the desired airplane in the "Aircraft" directory in the main Flight Simulator folder. Make a note of the current value of the "empty_weight" line, then change it to zero so it appears as follows:
empty_weight = 0 // (pounds)
Save the file and start the game. Then, purcahse that aircraft for $0, or you can enter any dollar value to actually earn that amount after it is purchased. Exit the game and edit the aircraft.cfg file again. Change the value of the "empty_weight" line back to its original value.
While playing under the hardest difficulty setting, look for airplanes being sold for about $20,000 (for example, Caranedo). Buy the plane and without exiting the company manager, quickly sell it back. You will make a $10,000 profit. As long as the company manager is still open, you can repeat the task using the same aircraft.