QE or Quadrantal Error refers to any directional errors in the North, East, South, West quadrants that may exist due to the shape of the aircraft. Most ADF systems are factory adjusted to compensate for the average amount of quadrantal error. Therefore, little or no QE compensation adjustment should be required. If an error is encountered, a procedure of turning the aircraft and comparing the ADF indicator with a directional gyro or compass to determine the error is performed. This procedure will be detailed in the installation manual.