- More than 1,000 airports without ground-based landing systems now have satellite-based WAAS precision approach procedures so pilots can land in low visibility
- Cape Air is providing 10-minute shorter flights using satellite-based WAAS routes
- With WAAS, Horizon Air has cut fuel consumption by half a million gallons per year
- Northern Air Cargo saves more than $196,000 and 113 metric tons of carbon dioxide emissions per aircraft per year with WAAS
- Performance Based Navigation (PBN)
- Addresses ways to leverage emerging technologies, such as satellite-based Area Navigation and Required Navigation Performance, to improve access and flexibility for point-to-point operations.
For many, the best part of a flight is getting to the destination. Being able to land at the airport is essential, whether the pilot is flying passengers or cargo. When the weather is nice and visibility clear, that isn't a problem. But when rain, fog or darkness obscures the runway, pilots must rely on onboard instruments and navigation systems on the ground.
While large commercial airports have instrument landing systems (ILS) installed on the ground at each runway end, many small airports don't have them at all. ILSs provide the lateral and vertical guidance required for precision approaches during low visibility conditions. But a proven satellite-based navigation capability enables approaches to more than 1,000 airports without an ILS and to more than 700 airports that may only have an ILS at one end of the runway.
This capability, known as Localizer Performance with Vertical Guidance (LPV), is a precision approach procedure that provides the lateral and vertical guidance that enables equipped aircraft to get within 200 feet of the runway before the pilot has to see the runway to land. Such precise approaches are possible because of the Wide Area Augmentation System (WAAS). WAAS, which made its debut 10 years ago in July, improves the precision of GPS satellite positioning information to ensure pinpoint accuracy.
LPV approaches enable pilots to land even when visibility is low, providing safe access to airports that may have otherwise been off limits.
The improved accuracy of GPS positioning that WAAS provides also enables more direct flight paths that can reduce distance in high-altitude airspace between airports.
From medical rescue helicopters to cargo carriers bringing supplies to remote villages, WAAS-enabled capabilities are providing great benefits to people across the United States.
Not bad for a 10-year-old.
Making Short Flights Even Shorter
The flight between New York's capital to the town of Ogdensburg, N.Y., on the St. Lawrence River is not the most travelled. But for the passengers who make the trip, it's an important route. Regional airline Cape Air makes the flight several times a day. And now, thanks to WAAS, it's 10 minutes faster.
"It doesn't sound like much, but it means a lot," said Tammie Irwin, Cape Air safety director.
The Albany-Ogdensburg flight is faster because the WAAS route is 37 nautical miles shorter than the traditional route. WAAS benefits are so impressive the airline is outfitting its entire fleet with WAAS-enabled GPS units. Cape Air, which flies to 36 U.S., Pacific and Caribbean locations using mostly small, 6-passenger aircraft, has already equipped 80 percent of its 70-aircraft fleet. The average flight times to Cape Air's various destinations is one hour.
Shorter flights between the two New York destinations translate into significant fuel savings: $78.89 per flight, Cape Air reported to the FAA.
WAAS capabilities also help the air carrier remain competitive. "We service destinations that are hard to get to by car and boat," Irwin said.
Many of the carrier's flights go to small, often rural airports that often are not equipped with ground-based navigation equipment. Before Cape Air had WAAS-equipped aircraft, the airline was forced to cancel or divert flights when visibility was low at the destination airport while competitors continued operations. Flying to an alternate airport costs the airline $1,000 and potential passengers, Irwin said.
Cape Air pilots now have the benefit of WAAS approach procedures and can complete flights even in low visibility. With WAAS, "we have considerably fewer cancelations," said Evan Cushing, Cape Air pilot and manager of the carrier's Safety Management Systems.
A "Game Changer"
When you're consistently flying through challenging weather and mountainous terrain, landing can prove a bit tricky. Horizon Air, a regional airline flying mid-size aircraft in the western United States, realized early that WAAS would increase the reliability of its flights, reducing delays and cancellations. It also proved to save on fuel costs.
"It's a game-changer. WAAS is better than we thought it would be," said Perry Solmonson, Horizon Air's director of flight standards and training. "WAAS has proven to be more reliable than the ground-based navigation equipment in the northwest. The WAAS approaches are available more often."
The technology also contributes to a more comfortable passenger experience. Solmonson described the result as "a sedate and muted ride. You like excitement at Disneyland but most passengers don't like that in their airplane ride," he said.
The regional airline mostly uses WAAS during arrivals to small airports, often in mountainous areas, such as Montana destinations Missoula, Bozeman and Kalispell, Solmonson said. Without WAAS, the carrier might have to delay or cancel a flight in poor weather. Delays cost the airline $50 per hour and cancellations cost $5,000 per flight, he explained.
WAAS allows Horizon pilots to file more direct routes and the aircraft to carry less fuel. Before equipping with WAAS, Horizon aircraft carried up to 1,000 pounds of extra fuel because basic GPS can be unreliable in certain weather and terrain. Horizon augmented its GPS with WAAS, which has the integrity, accuracy and availability to be used as a primary navigation source. As a result, the carrier has cut fuel consumption by half-a-million gallons a year, said Solmonson.
After evaluating WAAS on seven aircraft, Horizon Air retrofitted the rest of its fleet with the technology. Horizon now operates 48 WAAS-equipped aircraft on a daily average of 350 flights to 45 U.S., Canadian and Mexican destinations.
Medevac Gets a Shot in the Arm
Heart attacks. Car crashes. Premature births. These potentially life-threatening scenarios call for urgent medical care. For Mercy Medical Center in Des Moines, Iowa, WAAS makes it more likely its helicopter emergency medical teams can answer the call, even in low visibility.
Using WAAS, Mercy's helicopters can access helipads and runways in poor weather with visibility as low as 200-300 feet compared with 700-800 feet without WAAS.
"In 18 months, we've been able to accomplish as many as 20 missions that otherwise we would not have been able to do. Patients would have had to go by ambulance," Mercy flight nurse Jeff Johnston said.
Takeoff from the hospital's rooftop helipad happens within minutes of receiving a call for help. Air Methods, Mercy's helicopter operator, retrieves patients as far as 125 miles away at the Minnesota border, while Mercy flight nurses and paramedics treat patients in transit.
Last year, Air Methods flew 1,250 missions for the hospital. About 100 of these involved WAAS, said Air Methods pilot Joel Prybylski.
Prybylski compared a recent 44-minute round trip flight using WAAS from Mercy to another hospital. Before WAAS, low visibility would have prevented Prybylski from departing, and ground transportation would have meant a much slower response.
Des Moines International Airport is 15 traffic-choked miles from Mercy while Ankeny Regional Airport is 10 miles away. Driving an ambulance to either airport to fly elsewhere takes at least 30 minutes each way, adding up to an hour of transit time, Prybylski said. Ambulance-only travel — the worst-case scenario — could take up to three hours.
The shortened transfer time is critical in a medical crisis. "The quicker patients get to the facility providing treatment, the better outcomes they have as far as being healthier and more productive after their care," Johnston explained.
More direct flights also limit exposure to harsh weather for both patients and medical equipment, which can freeze in below-zero temperatures.
In addition to Mercy Medical, WAAS has improved access to helipads at three rural Iowa hospitals in Centerville, Albia and Osceola. There is also a WAAS approach to a community helipad located next to Interstate 80 in Stuart, Iowa, where helicopters can easily meet ambulances.
Bringing Home the Bacon — and the Snow Blower
People in remote Alaskan villages are less likely to run out of diapers, oranges and medicine, thanks to LPV procedures enabled by WAAS. The technology gives access to isolated areas when weather might have otherwise prevented the delivery.
Anchorage-based Northern Air Cargo uses WAAS every day to fly the dry goods and food that make up life's routine: fruits, vegetables, soft drinks, lumber, drilling pipes, snow blowers and U.S. mail. The all-cargo carrier flies to 12 Alaska destinations several times per week, including Aniak, Deadhorse, Nome, Red Dog Mine and Unalakleet.
"Villages are not linked by roads. Stores run out of milk and groceries [if our flights don't arrive]," said Timo Saarinen, Northern Air vice president of flight operations.
Dependable deliveries, no matter the weather, affect more than hungry shoppers — local economies depend on air service. "A construction company may have to cease operations while waiting for a new pump from Anchorage," Northern Air noted in a report to the FAA.
"Reliability is important for construction projects because the construction season is short," Saarinen said. The season lasts two to three months in the northern part of the state and four to five months in western Alaska, he noted.
Northern Air's typical flight is 60-90 minutes, and during that brief period the weather can change dramatically.
"Weather forecasting is a challenge," said Nate Martin, Northern Air chief technical pilot. "Alaska doesn't have a lot of reporting stations. Wind patterns can change in an instant."
If weather or visibility thwarts a landing and Northern Air is unable to complete a delivery, the costs spiral quickly. A flight turning back to Anchorage can cost the company $10,000 in fuel, Saarinen said.
Starting in 2009, the carrier upgraded the navigation systems on its aircraft to include WAAS-enabled GPS, which allows Northern Air pilots to use LPV approaches to safely descend closer to the runway in many cases than in the past. This increases the likelihood of making the landing rather than having to divert to an alternate airport.
For Northern Air Cargo, WAAS usage is more than bad weather and a short construction season.
"We use WAAS on a daily basis whether the weather is good or bad," Martin said. "It's becoming more than approaches. It's becoming routine. It helps save fuel costs and maintain schedule."
Northern Air calculated WAAS-derived benefits, including fuel savings and diversion reductions, are more than $196,000 per aircraft per year. WAAS efficiencies also translate to a roughly 113-metric-ton reduction of carbon dioxide emissions per aircraft per year, Northern Air noted.
And that helps keep Northern Air in business.