The United States was facing another major aviation disruption on Wednesday as the Federal Aviation Administration ordered a halt to all domestic flight departures after the system providing pilots with pre-flight safety notices went offline. The FAA said in a statement it had ordered airlines to pause all domestic departures until 9 a.m. Eastern Time while it tried to restore its NOTAMS — or Notice to Air Missions — system. “We are performing final validation checks and repopulating the system now,” an earlier FAA statement said. “Operations across the National Airspace System are affected. We will provide frequent updates as we make progress.” The association representing US airlines, Airlines for America says the outage is “causing significant operational delays.” United Airlines said it has temporarily delayed all domestic flights. American Airlines said in a statement it is “closely monitoring the situation, which impacts all airlines, and working with the FAA to minimize disruption to our operation and customers.” The NOTAMS system that is experiencing the outage provides “critical flight safety operation information,” the airline says. Transportation Secretary Pete Buttigieg tweeted, “I have been in touch with FAA this morning about an outage affecting a key system for providing safety information to pilots. “FAA is working to resolve this issue swiftly and safely so that air traffic can resume normal operations, and will continue to provide updates.” FlightAware, which tracks delays and cancelations, showed nearly 1,200 flights to, from and within the United States as being delayed as of 6:45 am ET, but only 93 flights canceled so far. Commercial airline pilots use NOTAMS for real-time information on flight hazards and restrictions. The FAA stipulates NOTAMS are not to be relied on as a sole source of information, and so some flights may be able to satisfy safety requirements by using other data. — CNN