Juneau equips ground vehicles with ADS-B to reduce incursions

 - July 24, 2007, 9:41 AM

While most ADS-B installations will be in aircraft, system proponents see the technology being applied in other ways. At Juneau, Alaska, FAA Capstone officials and airport personnel have launched a project that places the airborne equipment in airport vehicles. This has two benefits. First, in low visibility it alerts pilots of approaching ADS-B-equipped aircraft of the whereabouts of vehicles and, especially, their proximity to the runway. Second, and conversely, it allows vehicle operators to see landing and taxiing aircraft under the same conditions.

At Juneau, ADS-B systems have been installed in 15 vehicles. Five carry the conventional avionics package fitted in early Capstone aircraft, with a Garmin MX-20 multifunction moving-map display in the driver’s cab. Another five have the same avionics, but with a custom-built Trios moving-map display in their cabs. The last five carry basic ADS-B transceivers with no displays.

Over a 12- to 18-month period the project will evaluate (from the vehicle operators’ point of view) how effectively the different combinations prevent surface accidents, the key requirements being simplicity of presentation and minimal driver operating procedures. The five non-display installations will assess the effectiveness of monitoring the vehicles’ movements from a central airport dispatch office and advising drivers of aircraft movements over the two-way radios that all vehicles carry.

AIN witnessed an operational demonstration at Juneau while traveling around the airport aboard an Oshkosh diesel truck, used for snowplowing and as a heavyweight dump truck. Being perched high above the ground in the right-hand seat of this 45,000-pound (excluding snow plow), 650-horsepower behemoth afforded an excellent view of the surroundings, even without a map. But the Trios ADS-B moving map was the icing on the cake.

Simply turning on the ignition brought the display to life and, as we set off majestically across the ramp and rumbled down the flight line, a yellow diamond continuously indicated our precise position on the map, with its arrowhead showing our direction of travel as we headed toward the exit to the taxiway. Turning right onto the taxiway caused the arrowhead to slew around with us, straightening up as we completed the turn to point unerringly along the taxiway ahead.

Elsewhere on the map, two other clearly visible yellow diamonds were moving separately around the airport as part of the demonstration: one was a second Oshkosh snow blower, the other a massive road grader with a 24-foot-wide rotating broom, used in the winter to clear slush off the runway, taxiways and ramps. Even in zero visibility, there would be no risk of running into these or any other ADS-B-equipped target.

The evaluation approach taken at Juneau is typical of that adopted throughout the Capstone project. That is, start with the end users–pilots and truck drivers rather
than electronics engineers–and keep tweaking the system until it fully meets their operational needs. Pilots who used early panel-mounted loran and GPS sets must have often wondered who dreamed up the diabolical knob-twisting, button-pushing sequences required to get fairly basic information–not working pilots, for sure.

By comparison, the snowplow’s Trios display was startlingly simple. Touching the screen brought up just a short list of options, including north up, track up and zoom, which was overlaid on, but did not obscure, the map. Touching zoom allowed the map scale to be increased or decreased, and with it a driver near the runway could, when advised over the radio of an approaching aircraft, expand its coverage to several miles out and follow an ADS-B aircraft as it approached, touched down, rolled out and taxied in. “Really nice,” said snowplow driver Mark Lykins, a heavy-equipment operator at the airport for 15 years. “That’s going to be very handy, come winter.”

Capstone officials see their user-oriented approach paying off as operators start to realize the benefits that ADS-B brings. Recognizing the operational improvements from Capstone Phase I in the airspace around Bethel, Alaska, one air carrier is already upgrading to newer twin equipment, and others are expected to follow. Capstone Phase II, covering southeastern Alaska, is just starting up with around 50 aircraft equipped, out of an eventual 200 participants.

As Capstone project manager John Hallinan put it, “It’s a win-win situation for both the operators and the FAA. The government made the initial investment but, as the safety and other benefits become clear, operators are now starting to invest as well. In the long term, as we move into Capstone Phase III, which will bring state-wide ADS-B implementation under the Administrator’s Flight Plan 2004-2008, you could see our business plan dovetailing into the operators’ business plans, for our mutual benefit.”