I asked this before in the newbies forum but no expert ever answered. I'll ask again: Various airplane gyro gadgets require that the plane must be set in a "level" configuration to make an initial setting of the gyro. My question is, how do I determine if the plane is level? Put a level on the rear stabilizer? What if the rear stabilizer is not flat? Arrange the plane so a line from the center of the prop to the rear of the plane is level? How do you determine the "rear of the Plane"? Arrange a level on the bottom of the wing? What if the bottom of the wing is not flat. Please give an expert explanation. If not, please give an expert opinion. If not, please give an expert guess. If not, please give an expert "I don't know!"