  We present a systematic analysis of the effects of orbital inclination angle
on the non-linear variability properties of type-B and type-C QPOs from black
hole binaries. We use the bicoherence, a measure of phase coupling at different
Fourier frequencies for our analysis. We find that there is a likely
inclination dependent change in the non-linear properties of type-C QPOs as the
source transitions from a hard intermediate state to a soft intermediate state.
High inclination (edge-on) sources show a change from a `web' to a `cross'
pattern, while the low inclination (face-on) sources show a change from a `web'
to a `hypotenuse' pattern. We present a scenario of a moderate increase in the
optical depth of the Comptonising region as a possible explanation of these
effects. The bicoherence of type-B QPOs do not exhibit any measurable
inclination dependence.
