More than 6,000 U.S. flights delayed

More than 6,000 U.S. flights were delayed on Tuesday, May 19, as severe weather and air traffic restrictions disrupted operations across the national aviation network. FlightAware’s MiseryMap showed 6,412 delays and 412 cancellations at one point during the day, while the Federal Aviation Administration’s National Airspace System dashboard listed possible ground stops or delay programs at San Francisco, Dallas-Fort Worth, Miami-area airports and Denver. United Airlines was among the carriers hit hardest at major hubs including Chicago O’Hare, Denver, Newark and San Francisco, according to the aviation update cited in the original report and airline flight-status pages. The FAA’s dashboard also showed route-management measures affecting Chicago-area traffic and possible restrictions extending into the evening. The disruption came days before the Memorial Day travel rush, when AAA has forecast millions of domestic air passengers. (flightaware.com) Tuesday’s delays were driven by the combination of thunderstorms, airport flow controls and network congestion that can spread from one hub to another as aircraft and crews fall out of sequence. ### Where were the biggest pressure points in the system? The FAA’s National Airspace System dashboard on May 19 listed San Francisco as facing a possible ground stop or delay program after 3 p.m. (nasstatus.faa.gov) PDT and Denver as facing a possible ground stop after 9 p.m. PDT. The same dashboard listed possible route constraints for New York-area traffic, Florida-bound satellite traffic and Chicago-area arrival routes through 2 a.m. Chicago O’Hare’s official delays page showed 145 delayed flights and 19 cancellations over a 24-hour period, with 2,550 total flights counted on the board. (nasstatus.faa.gov) The page said the figures were provided by OAG and excluded cargo carriers. ### Why did weather and FAA caps cause so many knock-on delays? The FAA manages traffic flow by slowing arrivals and departures when weather, runway limits or airspace congestion reduce airport capacity. (nasstatus.faa.gov) The agency’s older National Airspace System status summary showed delay programs tied to weather and thunderstorms at airports including LaGuardia and San Francisco, along with ground stops at some locations. Flight disruptions can spread beyond the airport where the first restriction is imposed because aircraft, pilots and flight attendants are scheduled to move through multiple cities in sequence. (flychicago.com) When a hub such as Newark, O’Hare, Denver or San Francisco slows down, later departures elsewhere can also be delayed while waiting for inbound aircraft or available crews. This is an inference based on how hub-and-spoke airline schedules operate and on the FAA restrictions listed Tuesday. (fly.faa.gov) ### What was happening at Newark, Denver and San Francisco? Newark Liberty International Airport’s official site showed live arrival and departure status pages on Tuesday, and United’s Terminal C operation remained a key pressure point because the airline is the airport’s largest hub carrier. Newark’s airport site also showed real-time departure tools and security updates for travelers checking their flights. Denver International Airport’s official arrivals page and San Francisco International Airport’s flight-status page both directed travelers to real-time flight information as delays changed through the day. (nasstatus.faa.gov) San Francisco’s airport site notes that United is a hub carrier there as well. ### What should travelers watch next? The FAA’s National Airspace System dashboard updates throughout the day and is the clearest source for ground stops, delay programs and route restrictions affecting U.S. airports. (newarkairport.com) Airline-specific flight-status pages, including United’s, provide the most direct read on whether a particular itinerary has been delayed, canceled or rebooked. Wednesday, May 20, will bring the next test of whether Tuesday’s disruptions clear overnight or spill into the next day’s schedule. (flydenver.com) Travelers booked through hubs such as Newark, Chicago O’Hare, Denver and San Francisco can monitor the FAA dashboard and their airline apps for updated departure times and any waivers. (nasstatus.faa.gov)