  The extension of the KDA analytical model of FR II-type source evolution
originally assuming a continuum injection process in the jet-IGM (intergalactic
medium) interaction towards a case of the jet's termination is presented and
briefly discussed. The dynamical evolution of FR II-type sources predicted with
this extended model, hereafter referred to as KDA EXT, and its application to
the chosen radio sources. Following the classical approach based on the
source's continuous injection and self-similarity, I propose the effective
formulae describing the length and luminosity evolution of the lobes during an
absence of the jet flow, and present the resulting diagrams for the
characteristics mentioned. Using an algorithm based on the numerical
integration of a modified formula for jet power, the KDA EXT model is fitted to
three radio galaxies. Their predicted spectra are then compared to the observed
spectra, proving that these fits are better than the best spectral fit provided
by the original KDA model of the FR II-type sources dynamical evolution.
