TACAN ranging works in m2k to m2k and even m2k to a10. What u need to do is to set freq 63 channels apart. For example lead puts tacan to Y01 and wingman to Y64. TACAN must be in A/A mode. Dont forget to change ur HSI (compas on front panel) to TAC parameter. TACAN only gives u range between planes, ignore bearings on HSI, they are fixed in place.