In June 1990, a dramatic incident occurred aboard a British Boeing aircraft during flight. A loud noise, similar to an explosion, was followed by a sudden vacuum at the front of the cockpit. The air rushed out, carrying unsecured items like papers and cups, and the captain was partially pulled out of the plane. The cockpit's front windshield detached due to explosive decompression, an event in which the sudden loss of cabin pressure causes the air to rush out violently. The captain survived thanks to the crew, who held onto his legs during the emergency descent. Meanwhile, the first officer was left alone at the controls, managing the aircraft without forward visibility and unsure if the captain was still alive. The cockpit windshield, designed to endure significant pressure differences at high altitudes, literally ejected from its frame, creating a gap directly in front of the captain's seat. An investigation later revealed that the windshield had been recently replaced before the flight. However, the screws used to secure the windshield were not all of the required diameter, as specified in the technical documentation. The difference was so slight—only a few tenths of a millimeter—that it could not be seen with the naked eye. This small discrepancy, however, was enough to compromise the entire structure. Cockpit windshields are held in place by multiple fixations, each designed to handle a specific portion of the force from pressure differences. Screws that are slightly too thin do not provide the same level of contact surface or shear resistance as those specified by the manufacturer. On the ground, this difference is not noticeable, but at high altitudes, where internal pressure pushes the windshield outward with great force, each undersized fixation is pushed beyond its actual capacity. The combination of these microscopic weaknesses eventually led to a sudden, complete failure. The incident underscored the critical need for thorough cross-checks when replacing essential parts like windshields. It emphasized the importance of not only verifying the presence of fixations but also ensuring their exact conformity to manufacturer specifications. A difference of just a tenth of a millimeter, invisible on the ground, was enough to turn a routine flight into a narrowly avoided disaster.