Abstract
The effect of a tendency toward coplanarity of sub-cores in gamma-ray–hadron families, observed in high-mountainous and stratospheric experiments with X-ray emulsion chambers at super-high energies, is discussed. Based on simulations within the framework of the traditional FANSY 2.0/QGSJ model and the radical FANSY 2.0/2D model, the possibility of studying coplanar energy flows in the cores of Extensive Air Showers (EAS) arriving at the surface of the ADRON-55 calorimeter is considered. An assessment of the sensitivity of the ADRON-55 calorimeter for studying the coplanarity effect of energy flows in EAS cores has been made.