Reprinted from Flyer – April 2000


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PORT TOWNSEND, Washington — “Good morning. This is Jefferson County International’s Automated advisory. Wind 320 at 16, altimeter 30.22. Conditions favor Runway 270.”

Don’t be surprised if you hear that the next time you key the mike for an airport advisory at Port Townsend’s Jefferson County International Airport (0S9) — even if there isn’t a soul on the field.

The airport is the first in Washington state to get a Superunicom. Similar to an automated weather observation system, the device provides pilots with airport advisories and radio checks.

Although the airport is small (the runway measures 3,000 by 75 feet), its proximity to the Canadian border, Customs and a fair amount of flight training made the acquisition of a field advisory system a must. Assistant Airport Manager Judy Skeen said the decision to install a Superunicom grew out of safety concerns. “Currently Port Townsend Airport is unmonitored,” she said. “We felt we had to do something. It gets really busy here in the summer.”

Skeen said an AWOS was considered, but after reading a story in the Flyer, it was decided that a Superunicom would be the better route.

“Superunicoms are more user friendly,” Skeen said, comparing it to pilot-controlled lighting. “With a few clicks of a mike, a pilot can get information. It is more ‘real time’. It advises you of wind shifts and changes in field status almost immediately. I believe with AWOS there is some time delay. In addition, Superunicoms will give radio checks. An AWOS won’t.”

Before making the decision, Skeen said she contacted people at airports around the country that use both AWOS and Superunicom systems. She heard nothing but good things about the Superunicom, and when she did the cost comparison, the decision was an easy one to make.  Skeen learned the average installation cost of an AWOS can be more than $100,000. The price tag to install a Superunicom is about $38,600.

The “user friendly” aspect of the Superunicom is also a big selling point.

“Pilots like it because they don’t have to switch frequencies,” Skeen explained. “Most fields have one frequency for their AWOS and another for Unicom. The Superunicom provides the space to talk and listen in one location.”

The Superunicom is manufactured by Potomac Aviation Technology Corporation (800-207-8999). According to the brochure that comes with the device, it is licensed and authorized for use by the FCC and the FAA.

The unit measures 24 by 24 by 16 inches and is located next to the airport’s wind sock. The system is programmed to know the runways and configuration of each airport. Weather information is gathered through sensors on the wind sock pole. The information is automatically updated and alerts pilots to significant conditions such as ground fog, crosswinds, wind shear and high density altitude. It also continuously measures current weather data and balances the relative importance of each bit of information against the level of congestion on the Unicom frequency. It is powered and available 24 hours a day, and recharges its internal battery at night from the airport runway’s lighting circuit.

When it comes to transmission etiquette, the Superunicom is the perfect pilot. It always listens before it transmits, so it doesn’t “step on” anybody.

On first contact, the Superunicom automatically greets inbound pilots. The length of the greeting depends on how busy the frequency is. On a slow day, the pilot might hear “Good morning, this is (fill in name of airfield here), automated advisory. Wind 320 at 16, altimeter 30.22. Caution: crosswind. Conditions favor Runway 24.”

The Superunicom then pauses, allowing others to respond on the same frequency. “For further service,” the Superunicom comes back, “Click your mike three times for an advisory, four times for a radio check.”

On a busier day a pilot might hear: “Good afternoon, this is (fill in name of airfield here) automated Unicom; click your mike three times for an advisory, four times for a radio check.”

As airport traffic increases, the message gets shorter and shorter, disappearing entirely at times when the pattern is full of planes and an extra voice on the channel would be intrusive.

The airport manager can select how often the greeting occurs to accommodate each particular airport. The system can also be set to offer an automatic airport advisory to pilots who are 10 miles away from the field. Pilots can control the delivery of the check by clicking the mike three times.


The message is delivered by what Skeen describes as a “pleasant male voice.”


Meg Godlewski covers general aviation in the Western United States. She can be contacted toll-free in Lakewood, Washington, at 800-426-8538, ext. 306, or via E-mail at