Norwegian Consortium Launches SCAT 1

The Norwegians are about to make aviation history. During the next two to five years, a consortium lead by Norwegian Air Traffic and Airport Management (NATAM) and regional airline Widerøe, along with Park Air Systems, Field Aviation East and Tucson-based Universal Avionics System Corp (Stand 7431), plans to implement Special Category 1 (SCAT 1) local area differential GPS precision approach landing systems at virtually all the stolports served by Widerøe.

It'll be the first time ever that such a system has been put into commercial service.

"Widerøe had a couple of high profile controlled-flight-into-terrain accidents, one in 1988 and another in 1993," said Captain Bjorn Ericksen, a senior technical advisor to the Norwegian CAA, noting that the carrier conducts 2,000 operations a week into Norway's numerous stolports.

"Obviously, we had to do something," Ericksen said. CFIT accidents involving Widerøe and other operators spurred the Norwegian parliament to take action in 1996. Norway's legislators determined that non-precision approaches were the main cause of the CFIT risk, so they mandated installation of electronic glide path guidance at all 27 small rural airports served by air carriers. Such airports, some of which have steep approaches, are often plagued by bad weather. In winter, many have little or no daylight.

As a precision instrument approach navaid, ILS was out of the question because mountainous terrain near the approaches to runways grossly distorted the glideslope signal. International aviation officials have all but pulled the plug on microwave landing systems, so they weren't viable either. That left GLS, short for GPS landing system, as the only practical alternative.

GLS is nothing new. Numerous air carriers, airport authorities, trade associations and regulatory agencies have conducted one-off, proof-of-concept GPS landing system projects during the last ten years. Most of these science projects involved installation of local area differential SCAT 1 GLS avionics and ground equipment.

If Norway's SCAT 1 plan goes through, it will mark the first time GLS has progressed from the science project stage to full-scale operational implementation. The Norwegians have proven SCAT 1 technology during extensive trials at far-north Bodø in 1998 and later at Torp, 75 miles southwest of Oslo. Now they're ready to go operational with SCAT 1 systems at all airports not equipped with ILS that are served by airlines.

The stakes are high for both Widerøe and NATAM. Widerøe plans to fit its entire fleet of de Havilland Dash 8-100s with SCAT 1 avionics, including dual GLS-1250 differential GPS boxes, dual UNS-1F FMS boxes and VDL Mode 2 datalink receivers. Field Aviation East will install the avionics.
Concurrently, NATAM plans to install Park Air Systems SCAT 1 GLS landing systems at 25 to 30 small airports at a cost of $7.5 million to $10 million, not including flight inspection proving flights. Installations are slated to begin in mid-2002 with the entire system completed in two to five years.

By Fred George