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ALASKA ICING STUDY / PIREPS

Pilot Reports Needed to Support Aviation Icing Study in Alaska

Few conditions get a pilot's attention faster than aircraft icing. Merely the forecast of icing conditions is often enough to keep many general aviation aircraft out of the sky or at least the clouds. But how accurate is that forecast? A project started here in Alaska may bring improvements to icing forecasts. Dr. Jeff Tilley, an atmospheric scientist at the Geophysical Institute, University of Alaska Fairbanks, is working on this problem. He is a member of a FAA funded team to develop new generation icing products appropriate to the Alaskan environment. But he needs the help of the aviation community to be successful.

Working with scientists from the Alaska Aviation Weather Unit and the National Center of Atmospheric Research, the team will take icing diagnostic algorithms currently under development in the lower 48 states, and adapt them to Alaska. Satellite imagery, high-resolution numerical weather forecast models and other data are the building blocks of the alogrithms. The team will start with existing icing alogrithms and modify or re-design them to work at high latitude. The results will be in the form of a graphic forecast product. A sample product may be found on the following web site: www.rap.ucar.edu/largedrop/integrated/index.html

Pilot Reports (PIREPS) are critical to the overall success of the effot, as they are needed to verify the actual presence or absence of ice. The current lack of PIREPs is slowing the progress of icing hazard forecasting in the Alaska Region. While filing PIREPs with Air Traffic Control will help, for actual ice encounters Dr. Tilley needs some additional information that may not be captured in a typical report. To fill this gap, he is having special post cards made up that pilots may drop in the mail (post paid) to the University. In addition a similar Web-based form may soon be available. These will be compared with reports filed with ATC and Flight Service and provide the basis to verify the icing products. One concern voiced by aviation groups was that Pilot Reports fall out of the FAA's system within a few hours. Even if this happens, Tilley said, the National Weather Service captures the information, and will be archiving the data for the duration of this study.

The study is expected to start this spring, and should last for a year or more. Target areas for concentration are Ketchikan, Juneau, Sitka and Cordova in southeast Alask; Dillingham, Bethel, and Dutch Harbor in the southwest; Nome, Kotzebue, and Barrow in the northwest; and, Galena in the interior. For more information on the project, contact Dr. Jeff Tilley at 907-474-5852 or email jeff@gi.alaska.edu and file those Pilot Reports as you fly!