dailynewsnblog
Jetliners over nine states lost contact with air traffic control in flight on Thursday for approximately two hours. The impacted center controls traffic to and from airports across Minnesota, Missouri, Kansas, South Dakota, North Dakota, Wisconsin, Michigan, Nebraska, and Iowa.
The equipment malfunction that cut off the jets in the air also led to ground stops, causing hundreds of delays. The Federal Aviation Administration has not yet announced the technical details of the problem that took down all radio and radar services from Minneapolis Air Route Traffic Control Center.
ATC Zero Over The Heartland
At approximately 2:00 PM local time, the Minneapolis ARTCC degraded to ‘ATC Zero’ as the outage of telecommunication and navigation equipment effectively rendered the facility unable to provide any control. Radar and radio capabilities were restored after two hours, but the disruption to regional air traffic severely impacted operations at every airfield in the 330,000 square mile region.
Even though the blackout only lasted two hours, it left planes stacked up on tarmacs across the Midwest. Aircraft already in flight were forced to divert to alternative flight paths to land outside the region. Cascading delays averaged from 90 to 205 minutes well into Thursday evening as airlines tried to reposition crews and aircraft.
One of the largest airports affected was 
Minneapolis Saint Paul International (MSP). According to KSTP, the immediate impact of the ATC Zero event was 87 departure delays, with carriers scrambling throughout the night to reconcile operations for Friday. MPR News reports that the airfield has returned to normal operations. Weekend travelers should expect a normal experience.
The FAA gave this brief statement to MPR News around 6:00 PM on Thursday:
“Services have been fully restored, and flights are returning to normal. The FAA is investigating the cause.”
Offline In The Twin Cities
Correspondents from KARE 11 News on scene at MSP after operations resumed reported that many flyers did not notice the impact of the ATC outage on their travel plans. The customers most affected were those headed to destinations across the Great Lakes region. KARE 11 also pointed out that there was a wider disruption to cellular and internet services around the Twin Cities area that surrounds MSP.
The telecommunications failure that crippled the ARTCC appears to have been one part of a much broader state infrastructure service interruption. After the network went down, it severed critical data and communications lines for multiple government and public services across the Twin Cities area.
MPR News stated that both early voting machines were disconnected and the Dakota County 911 lines were down for one hour during the same time frame as ATC. Minnesota IT Services spokesperson Juliana Schacherer commented that there is no indication the outage was a result of a cybersecurity breach.
Operational Resilience At The North’s Flying Capital
MSP is the largest hub in the area impacted on Thursday, and its airfield is designed to isolate itself from external utility failures like the internet disruption in the Twin Cities. The field has an independent, local network to keep ground services running inside the campus even if the airport is offline. MSP is also Delta Air Lines’ second-largest global hub. Because Delta controls over 70% of the airport’s market share, one benefit of that fleet concentration to recovery efforts was that MSP did not suffer from an uncoordinated scramble of dozens of competing airlines.
For the planes in flight, the Aircraft Communications Addressing and Reporting System (ACARS) was a vital backup line of communications after ATC went dark. While the FAA’s ground-based radar and radio towers in Farmington were completely dead, aircrew could still coordinate with Delta’s Flight Operations Center (OCC) in Atlanta. Meanwhile, the Traffic Collision Avoidance System (TCAS) served to deconflict planes in the air until ARTCC was back up.
The blind zone created by the ATC Zero failure only applied to high-altitude, long-range airspace. Once a plane entered the airspace controlled by MSP Tower, they were able to land using the normal procedures. Now that operations have normalized, the FAA investigation will identify how to prevent a repeat of Thursday’s incident. The ARTCC may be fast-tracked for modernization depending on the cause, given that there is already an ongoing ATC upgrade program nationwide to replace aging equipment.
