All of a sudden, when I create new flights the planes' engines are stopped. They always used to be running right away. How do I reset this so the engines are running as soon as the aircraft appears?

Load the default Cessna 172 plane - is the engine running?If not, start the engine and then save the flight as the *default* flight and then exit FS9.Start FS9 again and now every plane you select should load with engines running.