Google Earth Flight Simulator

2016-02-17 feature adds fun. Thanks to Keith Pickersgille for pointing it out

As of version of Google Earth 4.2 includes an undocumented Flight Simulator.

To find the Flight Simulator, enter "Lilienthal" in the "Fly To" box This only works the very first time you do this. Once you have found the flight simulator the first time, you can get to it
in future via the TOOLS menu, then ENTER FLIGHT SIMULATOR.

You have a choice of two different aircraft (F16 or SR22), and a large choice of airfields to start from, or start from the current location on view. Before you click on START FLIGHT, first click on HELP for a list of keyboard shortcuts.

The simulator is meant to be easy to fly, even for non-pilots. There are no complicated engine-start or takeoff procedures - simply add power (press the PAGE UP key) and off you go. Once you've found a nice vantage point, you can use the space bar to pause the simulator and enjoy the view for a moment. Then, keep your location constant while you look around using the CTRL and arrow keys. Flying is easiest with mouse controls (or a joystick
if you have one), but the full set of keyboard controls gives you greater functionality.

They even provide a user guide with keyboard shortcuts.