Michael Stills, International Operations Flight Dispatch, United Airlines
When planning polar operations, United Airlines relies on the NOAA Space Weather Prediction Center’s website to provide the latest space weather data.
SATCOM capability is lost at approximately 82 degrees north latitude as a result of satellite positioning. United has found that solar activity can impede HF capability, and therefore United monitors absorption data in the polar region. Degraded HF in the polar region can limit an aircraft’s ability to communicate with air traffic control and the company. This situation will be accounted for in the planning process and avoided. United is also aware of proton flux levels that may be a reason for concern during solar events.
The Space Weather Prediction Center in Boulder has created on its website the tab “Space Weather for Aviation Service Providers,” which focuses on the information pertinent to airline operations. In conjunction with alerts based on the NOAA space weather scales, the aviation tab provides a quick snapshot of current space weather.
Airline operations require a considerable amount of preplanning, and terrestrial weather forecasts are an integral part of this process. For polar flights any and all space weather trends or forecasts are taken into account and may include avoidance of the region if the severity of the event dictates per internal policy.
Space weather events do not regularly impact airline operations. There have only been several occurrences since 1999 that have caused United flights to deviate from optimum routes. Though infrequent, these events have been costly and significantly impact some of the long-haul flights. The duration of the events is also of importance.
When space weather events cause operational restrictions, the results have caused delays and fuel stops for flights normally capable of nonstop operations. Current policies protect for solar events, but having information in advance and increasing lead time for planning would be advantageous for the industry. United realizes that much of the data currently available is not specifically geared for aviation.