A $4.6 million system recently installed at Seattle-Tacoma International Airport (SEA) uses radar-and-optical-sensing technology to continuously monitor the airport’s central runway for foreign-object debris (FOD) that threatens airline safety.
SEA is only the second airport in the United States to install the RunWize technology, developed by Xsight Systems and installed and integrated by Varec Inc., a wholly-owned subsidiary of Leidos. The system utilizes proprietary FODetect software to alert airport officials when it detects debris. An adjunct to the system also detects wildlife and provides bird-hazard management, says Mike Ehl, director of operations and customer service at SEA.
“Foreign-object debris is an international problem that costs airlines hundreds of millions of dollars in damage every year,” Ehl said. “The frequency of FOD-damage is very, very low, but the consequences are very, very high and historically, it’s been one of the few elements that airports have little control over. So this is breakthrough technology in an area that hasn’t received much focus in the past.”
It’s been difficult to quantify the amount of damage caused by runway debris at SEA, which is operated by the Port of Seattle and is ranked as the 13th largest airport in the United States, with 37.5 million passengers in 2014, Ehl says. That’s because when an aircraft reports damage, it’s difficult to determine if it occurred upon take-off or landing at another airport.
“We’ve had incidents where a carrier will land and there’s fan-blade damage, but there’s no way of knowing if it occurred here or hours before while taking off,” he points out. “We find pieces of aircraft out there quite frequently. They’ve never caused any problems, but only because we’ve been lucky.”
Nonetheless, Ehl says he’s certain that the RunWize technology will make operations safer. A primary reason for his optimism: The system provides continuous monitoring, which is more comprehensive than the prior detection system, which relied on four daily visual inspections of each of the airport’s three runways.
“Visual inspections are just cursory and can’t detect threats as well as an automated system, which gives you continuous vigilance versus periodic human surveillance,” he explained. “We do four (manual) inspections a day, but there are roughly 250 operations between those physical inspections, so a change in conditions can happen at any point and leave you vulnerable in between those visual inspections.”
Along with increasing safety, the system also can boost efficiency by reducing the number of wasted trips operations specialists make to verify pilot reports of runway debris. In turn, that will decrease the number of costly runway shutdowns required to allow those visual examinations, says George Thuemling, the FOD program manager for Varec.
All this technology does not eliminate the human factor, Ehl points out. “Certainly, we still need both (people and technology),” he said. “But rather than closing a runway based on a pilot’s report, then going out there and finding nothing, we’ll know if there’s something out there before a plane even takes off. This is a belt-and-suspenders approach that increases odds of detecting something before an accident occurs.”
Timing is Everything
SEA officials have been looking into installing a debris-detection system for more than a decade; the earliest technology relied on a tower-mounted radar. They kept waiting for the technology to fully develop and become more affordable. The need to rebuild the center of the airport’s three runways, originally built in 1969, offered a perfect opportunity to invest in the detection technology, Ehl noted.
“Before this, the timing just wasn’t right,” he explains. “In 2008, when we built our newest (third) runway, we were already considering the FOD-detection technology, but it hadn’t advanced to the point where we could incorporate it, so we didn’t do it. But when we decided to rebuild the center runway, all the stars finally aligned with the technology being advanced enough and both the airport commission and the airlines feeling comfortable with incorporating it into the runway project.”
The $80 million runway project was funded by a $25 million grant from the Federal Aviation Administration (FAA) and airport development funds, he said. The runway-rehab project enabled the airport to install the detection system more cost-effectively, as opposed to retrofitting the technology onto an existing runway.
“It offered an elegant solution because the cameras and radars are incorporated into the runway edge lights,” Ehl explained. “We saved some money because we were able to use common conduit. And we were rebuilding the runway anyway. If we had to retrofit an existing runway, that’s a whole different ballgame.”
Radar-and-Camera Detection
The system’s cameras and radar rely on sophisticated detection algorithms to sense and pinpoint the location of runway debris. In inclement weather, just the radar-detection portion of the system operates; in good weather, both technologies work in tandem. The basic aim: To eliminate inefficient and time-consuming false alerts that vex runway personnel and close down runways for no good reason.
“The idea is that the system corroborates itself, if you will, by using two different kinds of detection technology,” Thuemling said. “With this system, if a camera shows something on a runway and the radar doesn’t, it won’t send an alert. It can also sense density, so it won’t alert on, say, a wrapper from a Snickers bar. So it eliminates false alerts.”
The system’s algorithms are programmed to detect only stationary objects. When the system does detect a foreign object, it sends an alert via a fiber-optic line. The system can be fine-tuned as sensitive as airport officials require, Thuemling says. “We’ve actually alerted on an ant,” he notes. “During the first couple months of operation, each airport needs to determine a tolerable level for an alert.”
The system uses GPS to locate a foreign object within one meter of its actual location. At night, the sensor that detects an object sends out a laser light beam that shows airport personnel exactly where the object is located, so they don’t have to aimlessly search hundreds of square feet of runway to find, say, a small bolt, Thuemling says. “If you can redirect just one or two airplanes to an adjoining runway while you deploy someone in a truck to run out to pick up a foreign object, they can do it in very little time,” Thuemling notes. “It’s a much more efficient method of FOD control.”
In addition, SEA officials opted for a web application instead of standard workstation configuration. The latter relies on a dedicated network, with a server linked to specific workstations. “But with a web application, anyone with access to the airport’s network can download an app that allows them access, at work stations or on iPads, to any information our system provides,” Thuemling explained.
Moreover, the system automatically distinguishes birds from FOD and then alerts the airport’s wildlife team in real time, day and night. The BirdWise technology can detect and identify wildlife within a 400-foot swath along the runway – up to 200 feet on each side, as measured from the center of the runway, Thuemling says.
“When we started looking at it, we realized it could assist us in bird detection,” Ehl explains. “We identified it as a supplement to our existing bird radar, which detects birds 20 feet and higher. This system mitigates the risk between ground level and 20 feet up.”
More Functionality Than Expected
The system also gives SEA officials the ability to visually examine aircraft upon touchdown or departure in emergency situations, instead of relying on a visual examination with binoculars during a low fly-by, Ehl notes. “It may not prevent an outcome, but it can help inform us about conditions if something occurs,” he says. “We can also monitor snow and ice conditions without having to send someone out to do a visual inspection.”
Another bonus: The system creates a FOD database that will help SEA officials track how much debris actually ends up on the runway, Ehl said.
“We like to be on the leading edge rather than the bleeding edge," he said. “There’s a lot of reticence on the part of airport operators worldwide to invest million of dollars in something when it’s still in the early phases of implementation. But the installation here went without a hitch…and the technology has almost immediately proven itself in terms of its capabilities. To my knowledge, we’ve already detected three objects since we started using the system two weeks ago.
“Our number one strategic goal at Sea-Tac is to operate a safe and secure airport…and mitigate those risks that are out there,” he continues. “This issue (FOD) has never really been pursued by airports. It’s difficult to quantify the severity of these events, but it’s an area of vulnerability that’s ripe for mitigation.
So far, SEA officials are very impressed with the FOD-detection system, Ehl said. “Eventually, we’d like to extend the same level of surveillance to the other two runways,” he adds. “But first we have to use it to gather data, then make a justifiable business case to pursue the other two.”
