The Friendly Skies: Made Friendlier with Precise Uninterruptible Power

On-line real-time computer and data processing systems such as United Air Lines´ Denver Computer Center have many and varying needs. Not only must the electrical power supply be continuous and disturbance-free, but the environmental support systems must not fail. This paper describes a facility, unattended for long periods, which provides for the needs of the people and the expensive equipment associated with that system, even if all outside utilities (except for communications) are lost. The facility, while dually functioning as a dynamic uninterruptible power supply as well as a total energy plant, has been described by some as ``The Friendly Skies´ Best Friend.´´