If you use the flight simulator, and just let the plane fly itself, it will eventually crash. It just does. It becomes unstable and eventually nosedives into the ground.
But there is a way around this. Here's how you do it...
1. Take off using the SR22.
2. Get up to a height of about 1500 to 2000 feet (about 500-700 metres.)
3. Put the plane into a nosedive. The Elevator setting should be just a little bit away from right up to the top of the slider.
4. Well that's all really. Make sure the plane is at full power, that the controls are centred, the landing gear is up and the flaps are at 0% and do nothing.
The plane will do an upside down loop and will fall away to one side, but all the time it will become slightly higher and slightly steadier. Eventually it will fly upside down and very slowly gain altitude. The propellor plane will max out at just a shade under 25,000 feet.
Despite you pointing it in a straight line, it will actually travel in a huge circle. Since it doesn't really exist, it doesn't use any fuel, and so you can leave it for hours or days or weeks, and because it goes slowly around in a miles wide loop, it will still be more-or-less in the vicinity of where you left it. Handy if you need it in a hurry.
By the way, if you're wondering how I managed to write "uʍop ǝpısdn ƃuıʎlɟ", it's because of this neat little website...