Methods, apparatuses and systems for use of a magnetometer calibration (MAG-CAL) application to calibrate a magnetometer while an aircraft is in-flight including: generating a MAG-CAL calculated pattern based on a set of aircraft parameters for the in-air magnetometer calibration, the set of aircraft parameters at least comprise: speed, bank angle, altitude and position of the aircraft; generating a set of waypoints that define a calibration flight path corresponding to the MAG-CAL calculated pattern; Configuring the calibration flight path of the MAG-CAL calculated pattern to be part of the original flight path of the in-flight aircraft to enable the aircraft while flying the original flight to proceed in part on the calibration flight path corresponding to the MAG-CAL calculated pattern; and enabling the aircraft to deviate while in-flight from the original flight path to the calibration flight path to enable a sufficient level of calibration for accurate magnetometer operation.