JUNEAU — Sam Gottstein has had some memorable flights, but nothing like the nail-biter coming into Alaska’s capital city earlier this year.
The flight between Anchorage and Juneau was uneventful until the final descent, he said, when visibility was cut to almost nothing and the plane shook.
“There was definitely a collective sigh of relief after we successfully landed, and I feel as if a number of the passengers felt like we bonded together over it,” Gottstein said.
It is experiences such as this that aviation officials hope to avoid, or at least limit, with a new system that alerts pilots to pockets of turbulence and highlights corridors of smoother air.
The airport, which is set among mountains with a channel and glacier nearby, is known for its wind shears and white-knuckle landings. It is the only U.S. airport to have the federally sanctioned turbulence-detection technology, known as the Juneau Airport Wind System, or JAWS.
Alaska Airlines, the only commercial carrier serving Juneau, estimates that data from the system allowed it to safely fly more than 800 additional arrivals and departures last year, according to the Federal Aviation Administration.
Though the system was formally commissioned by FAA this summer, a prototype developed by the National Center for Atmospheric Research has been operating for more than a decade, providing wind information for the carrier and, more recently, alerts.
The system app is publicly available, for pilots or anyone else, to download on their smartphones or digital tablets through the local National Weather Service office’s website. Alaska Airlines pilots get the alerts and wind information via a messaging system between air traffic control and pilots. They can also call the FAA flight service station for updates, a spokeswoman said.
Deputy airport manager Patricia deLaBruere said the system is extremely important, and will lead to safer skies around Juneau. The city, like most communities in Alaska, is accessible only by air or water.
The impetus for the turbulence-detection system dates back to the early 1990s when series of incidents, including a near-accident by an Alaska Airlines jet that encountered sudden turbulence, caught the attention of federal officials.
FAA suspended departure routes during severe easterly winds, but said it allowed Alaska Airlines to eventually resume using those routes using an operational specification based on wind measurements from mountaintop anemometers. This wasn’t a long-term solution, and FAA said that after it was determined that a warning system would be possible it asked the National Center for Atmospheric Research, which had designed a similar system for an airport in Hong Kong, to develop one for Juneau.
The process involved documenting where the winds were and understanding how the wind patterns correlated to areas of turbulence, said Alan Yates, the center’s JAWS program manager. Research aircraft was sent out when the weather was bad to gather data, and the center’s team also installed instruments along the coast and atop mountains near the airport.
The center says those instruments transmit data “multiple times” a minute, to help give pilots a near-real time read of conditions.
Yates called this a “one-off system,” unique to Juneau. But he said the technology exists to build a similar system elsewhere and with new techniques, in less time.
“We’d love to be in further rollout, beyond Juneau,” he said, but a request for that would have to come either from the aviation community or FAA. Meteorological and turbulence data would have to be gathered in any place seeking to use this kind of system.
The cost of the project over the last 10 years totals about $35 million, FAA spokesman Allen Kenitzer said.
FAA has not indicated whether it will use the system at other airports. Kenitzer said only that FAA now has the blueprint for a system that could be used elsewhere if the agency determined there was a need.