In various explanations of the event horizon which do not invoke the existence of a firewall (thereby upholding the dictum that an observer would not notice any difference upon passing the event horizon until she looked out the window), one uses the concept of a theoretical observer passing the event horizon. The more careful explanations (sorry, I know I'm not giving references, but I am sure the readers will be familiar with them) mention that the observer is some sort of specially constructed robot who would survive the tidal forces of the black hole. However, what would be the conditions necessary (minimum size of black hole, speed of spaceship, etc) , if any exist, for a human being to survive the passage into the inner part of the space defined by the event horizon (at least for a short time -- before he gets too close to the singularity)? I am referring to his own perception of his survival (I know that an outside observer would never see her enter) even though the event horizon may be defined by an outside observer. Thanks.