  Top physics provides a fertile ground for new-physics searches. At present,
most top observables appear to be in good agreement with the respective
Standard Model predictions. However, in the case of decay modes that are
suppressed in the Standard Model, new-physics contributions of comparable
magnitude may exist and yet go unnoticed because their impact on the total
decay width is small. Hence it is interesting to probe rare top decays. This
analysis focuses on the decay $t \to b \bar b c$. Useful observables are
identified and prospects for measuring new-physics parameters are examined.
