Recent X-ray observations show absorbing winds with velocities up to mildly-relativistic values of the order of \sim 0.1c in a limited sample of 6 broad-line radio galaxies .
They are observed as blue-shifted Fe XXV–XXVI K-shell absorption lines , similarly to the ultra-fast outflows ( UFOs ) reported in Seyferts and quasars .
In this work we extend the search for such Fe K absorption lines to a larger sample of 26 radio-loud AGNs observed with XMM-Newton and Suzaku .
The sample is drawn from the Swift BAT 58-month catalog and blazars are excluded .
X-ray bright FR II radio galaxies constitute the majority of the sources .
Combining the results of this analysis with those in the literature we find that UFOs are detected in > 27 % of the sources .
However , correcting for the number of spectra with insufficient signal-to-noise , we can estimate that the incidence of UFOs is this sample of radio-loud AGNs is likely in the range f \simeq ( 50 \pm 20 ) % .
A photo-ionization modeling of the absorption lines with XSTAR allows to estimate the distribution of their main parameters .
The observed outflow velocities are broadly distributed between v _ { \mathrm { out } } \la 1,000 km s ^ { -1 } and v _ { \mathrm { out } } \simeq 0.4c , with mean and median values of v _ { out } \simeq 0.133c and v _ { \mathrm { out } } \simeq 0.117c , respectively .
The material is highly ionized , with an average ionization parameter of log \xi \simeq 4.5 erg s ^ { -1 } cm , and the column densities are larger than N _ { \mathrm { H } } > 10 ^ { 22 } cm ^ { -2 } .
Overall , these characteristics are consistent with the presence of complex accretion disk winds in a significant fraction of radio-loud AGNs and demonstrate that the presence of relativistic jets does not preclude the existence of winds , in accordance with several theoretical models .