Final answer:
Observers convert direction to magnetic direction in artillery and mortar CFF requests to align with compass readings, adjusting based on local magnetic declination.
Step-by-step explanation:
In artillery and mortar calls for fire (CFF), observers will always convert direction to magnetic direction in the CFF request. This is because compasses measure magnetic direction, making it the most practical reference for field operations. That being said, the direction of fire direction (FD) has been determined to be at an angle of 53° south of west, which means that adjustments would need to be made to this angle based on the local magnetic declination to ensure that artillery or mortar fire aligns correctly with the magnetic compass readings.