  General relativistic magnetohydrodynamic (GRMHD) simulations of accreting
black holes in the radiatively inefficient regime show that systems with
sufficient magnetic poloidal flux become magnetically arrested disc (MAD)
systems, with a well-defined relationship between the magnetic flux and the
mass accretion rate. Recently, Zamaninasab (2014) report that the jet magnetic
flux and accretion disc luminosity are tightly correlated over 7 orders of
magnitude for a sample of 76 radio-loud active galaxies, concluding that the
data are explained by the MAD mode of accretion. Their analysis assumes
radiatively efficient accretion, and their sample consists primarily of
radiatively efficient sources, while GRMHD simulations of MAD thus far have
been carried out in the radiatively inefficient regime. We propose a model to
interpret MAD systems in the context of multiple accretion regimes, and apply
it to the sample in Zamaninasab (2014), along with additional radiatively
inefficient sources from archival data. We show that most of the radiatively
inefficient radio-loud galaxies are consistent with being MAD systems. Assuming
the MAD relationship found in radiatively inefficient simulations holds at
other accretion regimes, a significant fraction of our sample can be candidates
for MAD systems. Future GRMHD simulations have yet to verify the validity of
this assumption.
