The mildly relativistic jets of SS 433 are believed to inflate the surrounding supernova remnant W 50 depositing in its expansion possibly more than 99 % of their kinetic energy ( [ Dubner et al . , 1998 ] ) .
Where and how this transformation of energy is curried out , it is not yet known .
What can we learn from it that the jets decelerate and the deceleration is non-dissipative , i.e .
radiatively dark .
In this paper we unclose the observed deviations of the precessing radio jets of SS 433 , within a few arcseconds from a jets source , from the ballistic track , described by the kinematic model , as a signature of the deceleration which , on other hand , issues from the jets colliding with ambient medium .
For that we model kinematics of these colliding jets .
The ram pressure on the jets is estimated from the observed profile of brightness of synchrotron radiation along the radio jets .
We have found that to fit observed locus the radio jets should be decelerated and twisted , additionally to the precession twist , mostly within the first one-fifth of precession period , and further they extend imitating ballistic jets .
The fitted physical parameters of the jet model turned out to be physically reliable and characteristic for SS 433 jets that unlikely to be occasional .
This model explains naturally , and meets approval by a ) the observed shock-pressed morphology of the radio jets and their brightness , b ) the observed \sim 10 \% deflections from the standard kinematic model — just a magnitude of the jet speed decrement in the model , c ) regularly observed for the radio jets the precession phase deviation from the standard kinematic model prediction , d ) dichotomy of distance to the object , 4.8 kpc vs. 5.5 kpc , determined on the basis of the radio jets kinematics on scales of a sub-arcsecond and several arcseconds .
The latter fact once again convinces that the kinematic distance to SS 433 could not be correct without accounting for the jets deceleration .

The model proposed here several reveals evolution of SS 433 radio jets with distance .