Airline service to and from the Tri-Cities Airport slowly returned to normal Wednesday after a power outage knocked out a computer system that feeds weather information to commercial pilots about conditions at the airport.
The outage forced four Pasco-bound flights to divert to Seattle-Tacoma International Airport, where some passengers reported they rented vehicles to make the final, unexpected leg of their journeys to the Tri-Cities.
The disruption had a cascade effect as morning flights were delayed while airlines brought in equipment. A 6 a.m. flight to Salt Lake City was delayed past noon.
Ron Foraker, the airport’s manager, said the problem affected the Airport Surface Observation Weather System or ASOS. ASOS is a National Weather Service system that supplies local weather conditions to in-bound pilots when local control towers are not staffed.
Pasco’s tower closes nightly at 10 p.m. and reopens at 6 a.m.
The source of the problem remained unclear Wednesday afternoon. The Franklin Public Utility District confirmed its lines were operating normally. The utility said the Federal Aviation Administration installed a generator to serve the system.
The FAA, which is responsible for power lines on the airport, confirmed that there was no power to the ASOS equipment. But it was apparently unable to locate the actual problem.
A technician for the National Weather Service said its equipment was without power and back-up batteries had died.
By afternoon, ASOS was running on a generator, with a back up available to prevent a future outage.
The problem forced two flights from Seattle to head back, and sent flights originating in Portland and Salt Lake City to Seattle, as well.
A passenger on Delta Flight 2632 said his flight from Salt Lake City was approaching Pasco when the pilot reported he couldn’t legally land without current weather information.
The passenger, who didn’t want to give his name, said the plane landed in Seattle. Six passengers from various flights rented a van and drove the 3 1/2 hours across the mountains because of commitments in the Tri-Cities on Wednesday.
“Nobody was happy,” he said.
A Delta spokeswoman said Flight 2632 was its only diverted plane. The airline provided accommodations for passengers in Seattle and ran the flight to Pasco on Wednesday morning.
Foraker said several Delta flights that can independently access the ASOS system arrived as scheduled Tuesday but the other airlines do not apparently have that capability.
Alaska Airlines, operating as Horizon Airlines, confirmed a plane was unable to land. Because the incident was related to weather, it did not provide compensation to passengers, a spokeswoman said.
By Wednesday morning, the backlog had been cleared out but some regularly scheduled flights were delayed for several hours so planes could arrive to pick up the passengers.
The weather system is not part of the airport’s recent $41.9 million remodel and expansion, which dramatically improved the passenger terminal, ticketing and security screening operations.
While the computerized weather system was down, Foraker noted there was no actual weather problem to hamper flying. Temperatures were acceptable and the rain was not an obstacle for commercial airliners.
“Those are safeguards the airlines follow,” he said.
Foraker called the situation frustrating and pledged to find a better way to manage overnight weather reporting.
“We’re going to try to get a little bit smarter,” he said.