Google Earth has a flight simulator built-in. It offers 2 planes: jet fighter F-16, and a propeller plane Cirrus SR22.
To begin to fly from a airstrip, hold ⇞ Page △ to increase thrust, and when the jet is fast enough (wait for few secs), press ↓ to lift off. Then, click mouse left button to activate mouse control. Once the mouse control is active, moving your mouse controls your flight.
If you haven't used a flight simulator before, it takes some practice to not crash.
If you are not a flight simulator fanatic, you probably won't need to use any of the following, except the ⇞ Page △ for initial trust for liftoff.
|Increase Thrust||⇞ Page △|
|Decrease Thrust||⇟ Page ▽|
|Rudder Left||【⇧ Shift+←】|
|Rudder Right||【⇧ Shift+→】|
|Center Aileron and Rudder||c|
|Extend or Retract Landing Gear||g|
|Toggle HUD on/off||h|
|Increase Flaps||f or ]|
|Decrease Flaps||【⇧ Shift+f】 or [|
|Rotate Viewpoint (fast)||【Ctrl+‹arrows›】|
|Rotate Viewpoint (slow)||【Ctrl+‹arrows›】|
If you are thinking about exploring the world in Google Earth by plane, it's not good, because it's too slow. e.g. from San Francisco to New York takes 4 hours, even with F16.
On the other hand, directly manipulate the earth gets you around much faster, as if by magic. And you can zoom in, change angle, orientation, altitude, extremely fast. (See: Google Earth Mouse Navigation and Keys)
Also, if you fly, it's rather quite hard to control, especially when you want to change direction. Try flying from San Francisco to LA. You'll probably get lost, if you manage not to crash 50 times!