Chicago (IL) - A crash of the departure system computers belonging to United Airlines stranded thousands of passengers on Wednesday. The system crashed from 8 AM to 10 AM Central Daylight Time and caused 268 United flights to be delayed an average of one and a half hours. 24 domestic flights were canceled.
The computer system calculated the weight, balance and fuel needed for all outbound flights. Playing around with these numbers not only saves the airlines money, but can also avert a disaster. Every plane has a maximum takeoff weight and airlines use complex formulas to guesstimate average weights of passengers and their luggage. A plane that is too heavy or has too much weight in one spot may not gain enough altitude to clear the runway. Sometimes planes that are full with passengers and baggage may have to takeoff with slightly less fuel.
United Airlines has approximately 3600 daily flights.