This paper presents the design and implementation of a Passive Fault-Tolerant Control (PFTC) strategy for a coaxial counter-rotating octorotor based on the Super-Twisting algorithm. This second-order sliding mode technique ensures robustness with respect to uncertainties and disturbances and is also able to deal directly with faults and failures by compensating the actuators loss in the system without prior knowledge on the fault, its location and its severity. The effectiveness of this PFTC is illustrated through real experimental application to a coaxial octorotor,where two motors failures are considered.