ASPEN – Navigational equipment that serves the Aspen-Pitkin County Airport is expected to be back in service on Friday, the Federal Aviation Administration said Wednesday after completing successful flight tests of the system.

The FAA began replacing a localizer directional aid located atop Aspen Mountain on Oct. 8. The equipment aids pilots on an instrument approach to the airport, guiding them as they circle back for another attempt to land after a missed approach.

The $1.5 million project involved replacing the 22-year-old, wooden platform that held the old antenna array, and replacing the array itself with new, state-of-the-art equipment, according to the FAA. The localizer is located at the top of the Buckhorn ski run, near the summit of the ski area.

A snowstorm during the installation hampered progress, and the FAA discovered a power line that feeds facilities at the mountaintop affected the signal generated by the array to guide pilots. The terrain itself also created challenges for the antenna array, requiring its reconfiguration, according to Bob Kitson, manager for engineering services for the FAA’s western service area. Installation of a shield on the antenna platform was deemed necessary to help prevent signal reflection from the power line, and even snowcats grooming the slope below the array.

“Trying to get a signal that provides the required accuracy on that mountain is quite a challenging feat,” Kitson said Wednesday.

“We want to make sure we have a safe signal in space to provide guidance,” said Tom Waldron, manager of navigational aids for the FAA.

The equipment shutdown has affected United Express flights between Denver and Aspen when cloudy conditions required pilots to use an instrument approach to the local airport. As of Friday, SkyWest, which operates the United service, had canceled 63 flights as a result of the localizer repairs.

The system on Aspen Mountain works in tandem with a localizer at the south end of the airport runway that has remained operational.

janet@aspentimes.com