A small passenger plane was at an airport waiting to take off. The crew was very late and the plane had been made ready to take off as soon as they arrived. The travellers looked around impatiently waiting to depart. After some time, two men boarded the plane. Both were wearing pilot's uniforms and both had sunglasses on. One was feeling his way along with a walking stick, and the other was following the first guided by a seeing eye dog. The passengers laughed nervously thinking that it was part of some kind of joke. The two men made their way to the cockpit and the plane began rolling forward picking up speed very rapidly. As the plane's velocity got faster and faster there was no hint of the nose pulling up. The passengers realized that the plane was about to plunge into the lake at the end of the runway and began screaming in fear. Just at the last moment, the plane leapt into the air and the sounds of the landing gear retracting were heard. In the cockpit as the aircraft continued to climb the copilot turned to the pilot and said, "You know Jack, one of these days they're not going to scream in time."
Knowing is half the battle...
Of course, the other half is violence.