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Navigating the storm clouds

Weather problems cause more than 40 per cent of all flight delays in the U.S., according to U.S. Department of Transportation data.


May 9, 2012
By Brian Dunn

Weather problems cause more than 40 per cent of all flight delays in the U.S., according to U.S. Department of Transportation data. A recent study commissioned by the Federal Aviation Administration (FAA) estimates the cost of airline delays and cancellations at $6.7 billion a year. No such data exists for Canada, but weather routinely plays havoc with flight scheduling, agrees Capt. Barry Wiszniowski, chair, flight safety division, Air Canada Pilots Association.

Fortunately, there may be relief on the horizon. Airline pilots may soon have some backup in the form of an infrared camera mounted on the nose of the plane to help guide them to a safe landing in weather that’s so grey they would otherwise be forced to divert to a different airport. This will not only help get airline passengers to their original destinations on time more often in foggy, snowy and rainy conditions, but save countless wasted hours and millions of litres of jet fuel each year, experts maintain.

One of the producers of this new avionics software is Honeywell, which combines on a single cockpit screen the enhanced vision system of real-time infrared camera images with an artificial but 100 per cent accurate synthetic visual system schematic of runways and surrounding terrain generated from global positioning system data, according to Honeywell, and Kollsman, which manufactures the camera technology.

The enhanced vision and synthetic
vision systems used in business jets have been certified for use by the FAA. Honeywell and Kollsman are now waiting for certification of the combined technologies for general aviation.

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“The systems are definitely helpful in providing better visibility in reduced visibility situations and thus should have a positive impact on reducing weather-related delays,” says Les Aalders, executive vice-president of the Air Transport Association of Canada. “Other suppliers also manufacture this type of equipment, which is currently available on various business aircraft including those built by Bombardier.”

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The infrared image shows pilots the view of the runway ahead that they might not be able to see because of low visibility. The synthetic vision component provides the pilot with awareness of nearby obstacles ranging from air-traffic control towers to mountains that might not be clearly visible in bad weather.

“You can now see the runway upon approach regardless of the visibility conditions, like it’s a clear sunny day,” explains Larisa Parks, Honeywell vice-president of crew interface products.

By using the infrared camera image to see runway approach lights in poor weather, pilots would be permitted to reduce the landing minimum from an altitude of 200 feet visibility of the runway environment down to 100 feet, Parks adds. “At that point, you have to decide whether you can clearly see the runway or whether you have to go around and attempt another landing or divert to another airport.”

Apart from being an inconvenience for the airline and its passengers, the cost of fuel burn alone is pegged at $1,000 for a go-around and $3,000 for a diversion, says Parks. Although she has no breakdown on the number of diversions that occur each year in the U.S., Parks notes that during the 2010 winter holiday travel season, a combination of travel volume and bad weather resulted in 25 per cent of all flights being diverted.

The Honeywell software contains a data picture of every runway in the world and 90,000 natural and man-made obstacles, according to the company.

On one video, a plane is engulfed in murky skies 700 feet above the ground and no runway is visible, even with the infrared capability. But the computer builds a picture of the runway in the distance and draws a box around it. A flight path marker displays the route to the apron of the runway. The plane continues to descend to just above 200 feet and suddenly the runway approach lights show up on the cockpit screen. As the aircraft continues to descend, the actual runway appears through the cockpit windshield, allowing the aircraft to land.

It’s estimated to cost $500,000 per plane to install the system, according to Elbit Systems of America, the parent company of Kollsman. No airline is yet using the enhanced vision system, relying instead on what pilots can or can’t see through the windshield to determine whether a landing can safely and legally be accomplished.

Vision quest
Another technology that is currently installed on some aircraft is Honeywell’s IntuVue 3-D Weather Radar.

“Historically, a pilot had to be a radar technician in trying to determine what lies ahead. With IntuVue, the radar automatically scans the weather in front of an aircraft,” explains Jary Engels, chief Honeywell test pilot. “And with that information, a pilot can make a decision to fly above, below or through the weather or ask for a deviation.”

IntuVue produces a 3-D display of weather from the ground to 60,000 feet out to 320 nautical miles in front of the aircraft and scans and stores the data in a 3-D buffer to recreate a three-dimensional image of storm cells. As a result, it enables rerouting sooner through longer-range weather hazard detection.

Turbulence-related incidents cost airlines an average of $150,000 per incident or more than $100 million a year industry wide, according to Engels. IntuVue reduces delays and diversions, increases passenger comfort, and lowers maintenance costs due to wear and tear by as much as 30 per cent, he adds. IntuVue is available on the Boeing 777, B737, Airbus A320, A330 and A340.

Ground control
On the ground, a growing safety concern for pilots is what’s called “surface threats,” which include ramp collisions, pilots who enter onto the wrong active runway and planes running off wet or snowy airstrips. Airline pilots maintain that manoeuvring big planes around complex and busy airports, often at night or with poor visibility, is one of the most challenging parts of their jobs. The threat increases during the summer when recreational flying is at its peak, says Wiszniowski. “Taxiing becomes a critical phase of flight due to crowded aprons.”

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 The infrared image shows pilots the view of the runway ahead that they might not be able to see because of low visibility.  
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The Honeywell software contains a data picture of every runway in the world and 90,000 natural and man-made obstacles.  
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The synthetic vision component provides the pilot with awareness of nearby obstacles ranging from air-traffic control towers to mountains that might not be clearly visible in bad weather. Photos: HONEYWELL


 

There have been more than 200 pilot deviations and about 100 pedestrian or vehicle deviations in each of the last two years, according to NAV CANADA, which is one of the founding partners of the Runway Safety and Incursion Prevention Panel established on Jan. 1, 2006, to find ways to reduce the problem. Most deviations were categorized as posing little or low risk and only a handful were considered high risk, while only one or two were considered extreme risk.

An example of an initiative to prevent runway incursions (which involve two aircraft, aircraft and a vehicle, or an aircraft and a person) occurred on Oct. 25, 2007, when NAV CANADA began depicting “hot spots” on aerodrome charts or applicable aerodrome ground movement charts in the Canada Air Pilot. A hot spot is defined by ICAO as a location on an aerodrome movement area with a heightened risk of collisions or runway incursions, or a history of both, in which greater attention by pilots is necessary. Some pilots include these hot spots in their pre-departure or arrival briefings.

Charlottetown, Fredericton, Halifax, Montreal, Toronto and Vancouver have multiple hot spots, while Calgary’s hot spot is between taxiways C, G and runway 28 and Winnipeg’s is at the corner of taxiway G and B. Edmonton and Ottawa are the only two major airports that don’t have hotspots.

To emphasize the protection of active runways and to enhance the prevention of runway incursions, pilots are asked to acknowledge taxi authorizations that contain the instructions “hold” or “hold short” by providing a complete readback or repeating the hold point. With the increased simultaneous use of more than one runway, instructions to enter, cross, backtrack or line up on any runway should also be acknowledged by a readback, according to NAV CANADA.

Procedures were also changed to have controllers instruct an aircraft to either “cross” or “hold short” of any runway it will cross while taxiing. Therefore, unless an aircraft is specifically instructed to line up, to proceed/taxi on or to cross a runway, they should hold short of that runway.

Surface Detection Equipment has been installed at more airports enabling controllers to detect potential runway conflicts by providing controllers with a radar picture of movement on runways and taxiways.

In addition, Operational Systems Requirements and Engineering at NAV CANADA is currently exploring new surface detection technologies such as tracked video and implementing enhanced surveillance using multilateration fused with surface movement radar to improve runway safety. New ways of displaying critical information to controllers are also being developed.

In addition, NAV CANADA is working to reduce the incidences of runway incursions that occur when an aircraft fails to confine its takeoff or landing to the designated runway. This may occur during takeoff if the aircraft leaves the runway wihtout becoming fully airborne or if an attempted landing is not completed within the confines of the attended runway, according to NAV CANADA’s definition.

To reduce the number of these incidents, the Transportation Safety Board of Canada recommends that in bad weather, pilots receive timely information about runway surface conditions. Airports also need to lengthen the safety areas at the end of runways or install other engineered systems and structures to stop planes that overrun.