Hello!
Originally Posted by
FullWings
Better to have a phone app for emergencies - I use iBFD in case of a double failure in my panel.
That's better than nothing, but don't forget that this is not a real artificial horizon. The effects of turbulence and prolonged turns will make it unreliable in less than a minute. It can help to maintain level flight for a very short while but not more than that. The solid state accelerometers built into smartphones are just that: accelerometers. Not real gyroscopes. And it needs to be turned on and "calibrated", i.e. aligned with the horizon, before it can be used.