Recent analysis of the long term radio lightcurve of the extremely variable BL Lacertae object AO 0235+16 by Raiteri et al .
( 2001 ) have revealed the presence of recurrent outbursts in this source with a period of \sim 5.7 \pm 0.5 yr. Periodicity analysis of the optical lightcurve also show evidence for a shorter period .
Here we discuss whether such a behavior can be explained by a binary black hole model where the accretion disk of one of the supermassive black holes is precessing due to the tidal effects of the companion .
We estimate the mass of the accreting hole and analyze under what constraints onto the secondary mass and the orbital parameters of the system it is possible to provide a viable interpretation of the available multiwavelength data . \keywords Galaxies : active – BL Lacertae objects : individual : AO 0235+16 – Gamma rays : theory – Black hole physics