New Performance Based Navigation procedures into Gary, Indiana, are more fuel efficient and less stressful for pilots and controllers.
Legacy routes put inbound business jets at lower altitudes amid more general aviation aircraft south of busy Chicago airspace.
Operators at Gary teamed with the FAA and others to develop and implement the procedures over an 18-month period.
Corporate pilots flying into the Gary/Chicago International Airport from certain directions used to face increased workload from the very real possibility of traffic conflicts with low-flying aircraft operating under visual flight rules (VFR).
Thanks to an FAA- and industry-developed standard terminal arrival (STAR) procedure that is now in place, flights into Gary are now less stressful — for controllers and pilots — as well as more fuel efficient. The procedures are part of the broader FAA NextGen initiative to modernize all U.S. airspace.
"Being aware of surrounding traffic was an element of every approach briefing," says Bradley Sunshine, assistant chief pilot for Boeing Executive Flight Operations. Along with Boeing, several other large corporations and operators base their flight departments at Gary, including the Gary Jet Center and NiSource, a major utility company.
Using the "LUCIT 1" STAR, aircraft fly higher on performance based navigation (PBN) routes into Gary.
The new PBN arrival procedure provides three defined legs into the terminal area at Gary, all of which keep aircraft higher than typical arrivals in the past.
Before LUCIT 1, aircraft coming into Gary from the west would be vectored toward the airport via a legacy arrival route designed for Midway International Airport, approximately 20 miles northwest of Gary. That route ends at the Joliet VOR station about 30 miles west of Gary. After Joliet, large corporate jets would fly east at approximately 3,000 feet altitude (2,500 feet above the ground) at 250 knots airspeed (the maximum speed in that area) on the final leg to Gary. Sharing that low-altitude airspace are general aviation aircraft circumnavigating Chicago's Class B airspace.
"For jet aircraft to be that low for that long had operational hindrances — increased fuel burn, turbulence in summer, and icing in the winter," Sunshine says. "It wasn't ideal." Add to that the traffic alerts. "Our Safety Management System really came alight with Traffic Collision Avoidance System (TCAS) advisories," he says. Based on responses from the transponders on nearby aircraft, an onboard TCAS provides pilots with proximity warnings and occasionally with resolution advisories — climbs or descents — when a threat is imminent. The automated alerts could still be triggered despite controllers diligently pointing out the location and distance of surrounding traffic.
South of the Mode C veil of 30 nautical miles around Chicago, aircraft flying under visual flight rules are not legally required to have transponders. That possibility meant pilots could not count on TCAS or controller input, and had to resort to visual see-and-avoid tactics. One of the consequences for Boeing and other operators was that pilots would pre-emptively slow down after Joliet, to perhaps 200 knots, to give them time to maneuver around any traffic they saw. But that action also prolonged flight time.
It wasn't just the operators that were impacted. "The Chicago Metropolitan area is congested to begin with, but the area between Joliet and Gary is particularly busy with low-altitude aircraft, due to the high volume of Midway Airport traffic," says Earle Robertson, airspace and procedures support manager for the Chicago En Route Center (Chicago Center).
Controllers at Chicago Center and the Chicago Terminal Radar Approach Control Facility (C90) say previous procedures were complicated, because traffic coming in from the south to land at outlying airports, including Gary, was usually coming head-on into a high volume of departing traffic from O'Hare and Midway airports. By agreement, Chicago Center and C90 had to send the Gary-bound aircraft to altitudes below 4,000 feet to avoid flight patterns into Midway.
Pilots were aware of the extra workload for controllers. "It was very apparent that with every radio call the controller would make, either pointing out [VFR] traffic or vectoring us around it — or if there was an actual resolution advisory — it contributed to the controller's overall workload," Sunshine says.
"That convinced all of us that there was a need for a procedure, so we approached Chicago Center management with the idea," Sunshine says. "That was the spark that ignited the collaboration that transpired all the way through."
"All the way through" wound up being 18 months — the minimum time it typically takes to develop airspace procedures and gain FAA approval. The resulting STAR, published in July 2016, features three paths — one from the southeast, one from the southwest and one from the west — that lead to a final waypoint about 15 nautical miles south of the airport. While two of the paths are optimized profile descents (OPD), which typically allow for an aircraft to perform a fuel-efficient idling descent, the third path (arriving from the west) is more traditional in that the aircraft maintains a relatively constant altitude. The altitude is much higher than before — 10,000 feet compared to 3,000 feet "That part of the procedure keeps us, the Gary operators, higher and faster and away from the traffic," Sunshine says. "It helps us and it helps controllers."
To build the STAR, Sunshine and the other operators worked with officials at Chicago Center, C90 and the FAA's Operations Support Group — employees who specialize in designing and building performance-based navigation procedures.
"At first, the discussion focused on making everyone's situation better," says Jeff Herald, airspace and procedures support specialist at Chicago Center. That including reducing controller workload, cutting down flight time and fuel consumption, and reducing the time that pilots would have to spend tuning radios or programming avionics. For the procedures, the goal was to relocate the paths of aircraft landing at Gary from a highly congested area to an "under-utilized" area while flying at higher altitudes. In simple terms, the LUCIT 1 STAR threads a needle between Midway and O'Hare traffic, by going below O'Hare traffic but above Midway traffic.
"The post-implementation reviews have been exceedingly positive for both the operators and controllers," says Socrates Passialis, National Air Traffic Controllers Association Airspace Procedures Representative for Chicago Center. "In part, because the OPDs require controllers to issue one clearance rather than multiple crossing restrictions, cutting workload and frequency congestion."
An October 2017 performance assessment conducted by the NextGen Advisory Committee's Joint Analysis Team found that while operators were "pleased" with the new OPDs, there is not yet enough data to determine how much fuel is being saved.
The same is not true for see-and-avoid stress. "Our Safety Management System has shown that since the STAR has been implemented, our traffic concerns — which was one of the catalysts to pursue this — dried up overnight," Sunshine says. "That's really telling."