Possible complexes of three-dimensional planes in projective space $P^6(I)$

In the work possible complexes of three-dimensional planes in six-measured projective space $P^6$ are studied. It’s proved that one-parametric family of cones of second order in $P^6$ with univariate top and with three-dimensional flat forming defines four-parametric possible family of planes $E^3$ which are all three- dimensional forming to this cones.