FAA Assembly & Rigging Practice Test

The dihedral angle of a wing is the angle between its two wings relative to a horizontal plane, and it plays a significant role in the stability of an aircraft. The dihedral angle can be measured accurately by placing a straightedge along the front spar of the wing and using a level protractor to determine the angle. This method provides a direct and precise measurement of the angle, as the straightedge helps establish a reference line, while the level protractor can accurately gauge the angle between the wing’s surface and the horizontal reference.

Measuring the dihedral angle visually or through other less precise methods could result in inaccuracies, which is critical since the dihedral angle affects the aircraft's roll stability. Using a digital angle measuring tool on the wingtip might seem reasonable, but this method may not account for any irregularities or variations in the wing structure that could affect the accuracy of the measurement. Similarly, assessing wing shape visually is subjective and lacks the precision required for an accurate measurement. Adjusting the angle based on flight behavior is also not a viable method for measurement, as it relies on performance observations rather than a definitive measurement technique.