An adaptive interconnected observer for induction motor (IM) drive without mechanical sensors (speed sensor and load torque sensor) is presented. The observer estimates the fluxes, the angular velocity, the load torque and the stator resistance even under or near unobservable conditions. Practical stability based on Lyapunov theory is proved to guarantee the strongly uniformly practical stability of the estimation error dynamics. A contribution of this article is the experimental validation of the observer on reference trajectories of a sensorless IM observer benchmark. The trajectories of this benchmark are chosen to test the motor near and under conditions of unobservability. Robustness with respect to parameters variations is proved and experimentally verified.