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The Federal Aviation Administration had prior knowledge of risks that could stem from an equipment bandwidth issue that later caused at least three separate previously unreported radar failures on Sept. 2 at the facility that controls the busy airspace around Newark Liberty International Airport, according to a person directly familiar with the situation. These failures followed an earlier full radar outage at the Newark sector on Aug. 27, now marking at least four otherwise rare radar issues there in the course of just six days.
Radar failures present extremely dangerous situations for airplanes on the ground and in the air, as the systems provide the primary means for air traffic controllers to identify aircraft and manage traffic. Other systems, like the newer telemetry-based Automatic Dependent Surveillance – Broadcast (ADS-B), were not affected in either outage situation.
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The Air Current has learned that the issues on Sept. 2 were caused by a latency issue on a communications feed that was set up to provide primary radar information to the Philadelphia Terminal Radar Approach Control (TRACON), which is now home to the Newark sector in an agency bid to fix chronic understaffing and delays at one of the country’s most challenging air traffic control regions. The latency issue will take months to fix, the same person directly familiar told TAC — meaning outages may continue before things get better for America’s most snarled airspace.
Despite Newark controllers now working from Philadelphia, the airspace they are controlling has not changed, and information displayed on their screens is still coming in part from the Standard Terminal Automation Replacement System (STARS) based at the New York (N90) TRACON facility on Long Island. STARS is a fully digital air traffic data aggregator that compiles information from several different sources, which is used to populate the data block with relevant readouts for each aircraft that a controller sees at their workstation.
STARS brings together information from long-range radars (like those used for enroute centers), ADS-B, and Airport Surveillance Radar (ASR) systems located on the field at an airport. ASRs are the spinning dishes that use time-based radar pings to return information about aircraft position and altitude. In the case of N90, ASRs located at each New York airport — in addition to the other systems STARS feeds from — send information to the controllers on Long Island.
However, because the Newark controllers are no longer located on Long Island, the FAA set up a remote STARS feed from Long Island to Philadelphia (130 miles away) to allow the relocated controllers to access all of this radar information from afar. The information for this remote feed travels on what is known as a TELCO — or telecommunications — line, cables used for data transmission similar to those used for normal phone calls, for example.
On Sept. 2, the TELCO line servicing this remote feed in Philadelphia suffered a latency issue. Much like a home WiFi system, latency and bandwidth issues occur when a system can’t handle the amount of data being put through it (as when multiple family members are watching Netflix on different devices at the same time), elevating concerns that this system may not be able to handle the demand during peak traffic periods.
While an FAA spokesperson confirmed to TAC that the causes of the failures on Aug. 27 and Sept. 2 are not related, this known issue that caused the most recent failures represents a significant vulnerability in the system. The FAA says that they are still investigating the causes of both incidents but noted that these types of failures are very rare given that equipment in the national airspace system (NAS) has a reliability rate of 99.73%.
Mirrored or remote feeds, which are normally used to display radar data to facilities that aren’t co-located with the physical radar system, are common in the NAS — the FAA confirmed that over 400 facilities use this type of technology. In the case of N90, remote feeds are used to display the TRACON data at smaller airports within the area for controller situational awareness.
However, TAC is told that using remote or mirrored feeds for primary TRACON radar systems, like the ones being used at the relocated Newark sector, is less common, underscoring the difficulty of such a large airspace transition as well as an ongoing challenge within the NAS of sustaining and implementing properly functioning systems amid budgetary constraints at the FAA.
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Had the relocated Newark sector been added to Philadelphia’s STARS system instead of relying on a remote feed, this additional TELCO link — and the failures that it caused on Sept. 2 — may have been avoided altogether. A FAA spokesperson told TAC via email that “The FAA will move PHL Area C into the Philadelphia STARS TRACON system, eliminating the need of the remote connection. A series of software changes will take place starting this month, and the entire software build to remove remote connections is planned.”
However, two people familiar with the situation told TAC that the agency internally estimates it would take at least five years to fully migrate the Newark radar data to Philadelphia’s existing STARS infrastructure.
Regardless of the agency’s investigation into the Sept. 2 failures, additional outages could cause safety issues and headaches for the airport’s customers. United Airlines, the biggest user of Newark Airport, has supported the Newark relocation, but acknowledged — as did the FAA — that short term issues would impact travelers throughout early August as the operation was fully relocated. While a United Airlines spokesperson confirmed to TAC that the airline’s “pre-planned schedule reductions” meant to ease traffic during this transition period ended on Aug. 18, these radar failures along with staffing problems have continued to frustrate the airline and its passengers.
A United spokesperson declined to comment on the recent outages.
In a statement on the move issued on July 23, the National Air Traffic Controllers Association (NATCA) said that it “has raised concerns regarding the readiness of the necessary equipment and procedures to accomplish such a complex transfer of airspace.” A NATCA spokesperson declined to comment on the latest radar outage issues at Newark.
Write to Will Guisbond at will@theaircurrent.com
