Airports across the United States are bracing for severe travel disruptions beginning Friday, as the Federal Aviation Administration (FAA) moves to implement steep flight cuts at 40 of the country’s busiest airports amid the ongoing government shutdown.

The reductions — which could reach up to 10 percent of scheduled flights next week — come at a critical time, just as millions of Americans prepare for the Thanksgiving travel rush. Transportation officials warned that if the shutdown continues, cancellations and delays could quickly cascade nationwide.

Under the directive, major hubs including New York’s JFK, LaGuardia, and Newark Liberty, as well as Chicago O’Hare, Atlanta Hartsfield-Jackson, Los Angeles International (LAX), Boston Logan, and Denver International, are expected to take the largest hit. Airlines have already begun adjusting schedules and rebooking passengers.

Delta said it will begin reducing flights starting Friday but expects to maintain most long-haul international operations. United will prioritize keeping hub operations intact while cutting select domestic and regional routes. American Airlines said it anticipates “minimal disruption” for most customers but is preparing contingency plans.

Budget carriers, however, expect more turbulence. Frontier Airlines advised travelers to prepare backup plans, warning that rebooking options may be limited if flights are canceled.

The FAA will begin the cuts with an estimated 4 percent reduction in flights on Friday, rising to 6% by Sunday, climbing toward the full 10 percent cut next week if the shutdown remains unresolved.

With Thanksgiving only two weeks away, aviation analysts warn that even small schedule disruptions now may ripple into the holiday travel period.

“Once delays build up in the system, they don’t clear quickly,” one industry analyst said. “A few days of cuts could translate into a messy holiday travel week.”

LIST OF AFFECTED AIRPORTS

New York / New Jersey

• John F. Kennedy International (JFK)

• LaGuardia Airport (LGA)

• Newark Liberty International (EWR)

• Teterboro Airport (TEB)

Major U.S. Hubs

• Hartsfield-Jackson Atlanta International (ATL)

• Chicago O’Hare International (ORD)

• Los Angeles International (LAX)

• Denver International (DEN)

• Boston Logan International (BOS)

• San Francisco International (SFO)

• Seattle-Tacoma International (SEA)

• Dallas/Fort Worth International (DFW)

• Miami International (MIA)

• Philadelphia International (PHL)

• Phoenix Sky Harbor International (PHX)

• Orlando International (MCO)

• Charlotte Douglas International (CLT)

• Detroit Metropolitan Wayne County (DTW)

• Minneapolis–St. Paul International (MSP)

• Houston George Bush Intercontinental (IAH)

• Washington Dulles International (IAD)

• Ronald Reagan Washington National (DCA)

Additional Impacted Airports

• Baltimore/Washington International (BWI)

• Fort Lauderdale-Hollywood International (FLL)

• Chicago Midway (MDW)

• San Diego International (SAN)

• Salt Lake City International (SLC)

• Portland International (PDX)

• Honolulu International (HNL)

• Tampa International (TPA)

• Indianapolis International (IND)

• Cincinnati/Northern Kentucky (CVG)

• Memphis International (MEM)

• Louisville International (SDF)

• Anchorage International (ANC)

• Las Vegas Harry Reid International (LAS)

• Oakland International (OAK)

• Ontario International (ONT)