LOS ANGELES >> Nearly an hour after her American Airlines flight was scheduled to leave Daniel K. Inouye International Airport, passenger Lisa Hill heard the pilot announce that a maintenance problem would delay the takeoff.

The pilot gave flyers the option of getting off the plane, but Hill, who was flying to Boston after visiting her son, decided to remain seated, hoping to be in the air shortly.

Three more hours passed before the flight in November was canceled.

“For four hours I sat on that plane,” said Hill, co-owner of a housecleaning business. “When the pilot finally said we should deboard, it was like a Black Friday sale at Macy’s. Everyone rushed off.”

Now the Trump administration might roll back a rule that requires airlines to give passengers such as Hill the option of getting off a flight that is delayed too long on an airport tarmac. And that’s not the only regulation that might be weakened or scrapped.

Last year the U.S. Department of Transportation temporarily froze all pending airline industry regulations as part of an administration push to cut the burden of red tape on American businesses. And it asked the public and airlines for comments on existing regulations that could be halted, revised or repealed.

The so-called “tarmac delay rule” — adopted in 2009 after a series of incidents in which passengers were trapped in planes for hours — was just one of dozens that either airlines or an industry trade group targeted in response to the request.

The deregulation initiative is a dramatic shift for the federal agency, which under President Barack Obama adopted or proposed more than 80 airline-related consumer protection and safety regulations — prompting an outcry from the airline industry.

The agency also meted out stiff penalties. From 2015 to 2016 the Transportation Department increased the total amount of civil penalties on airlines and travel agents to $6.4 million from $2.4 million.

Southwest Airlines, for example, was fined $1.6 million for stranding passengers on 16 planes during storms on Jan. 1 and 2, 2014, at Midway International Airport in Chicago. Some passengers were stuck on the tarmac for more than four hours.

“The airlines are pretty clear that they want every consumer protection law repealed or not enforced,” said Paul Hudson, president of Flyersrights.org, a nonprofit group with more than 60,000 members.

Beyond the tarmac rule, other popular regulations that could be changed include one that requires airlines to advertise fares that include all fees and taxes. Another mandates that passengers be informed about how to file a service complaint with the department.

The deregulation push comes as the industry is basking in profit. Airlines reported a combined $17.6 billion in profit last year, a dramatic improvement from the nine years after the Sept. 11, 2001, terrorist strikes when the entire U.S. airline industry lost a combined $65 billion.

That improved financial performance resulted in an industry profit margin of more than 6 percent last year, compared with an average loss of 6.3 percent in the previous nine years, according to Airlines for America, a Washington, D.C.-based industry trade group. Still, carriers say the regulations imposed by Washington are hurting their bottom lines.

The 2012 rule that forces airline to advertise their full fares was in response to complaints from travelers who for years reserved tickets only to find that the final fare was as much as 30 percent higher when fees and taxes were included.

Now, when travelers search on airline websites, Expedia or other travel sites for a flight, they see the final price, with no hidden fees that cause sticker shock when it is time to pay the bill.

Another rule the industry is targeting is the 2011 regulation that gives passengers 24 hours after booking a flight the right to cancel and get a full refund. American Airlines told the department that it and other carriers already sell tickets with various options, including those that are nonrefundable and those that offer the right to cancel beyond 24 hours for a higher price.

Perhaps the highest-profile consumer rule adopted during the Obama administration was the “tarmac rule.” Under the 2009 law, airlines are required to provide water, food and access to bathrooms during long delays and must let passengers on domestic flights exit the plane if the delay on the tarmac lasts at least three hours. The rule extends to four hours for international flights.

Airlines can be fined as much as $27,500 for every passenger who is stranded. The rule was in response to several infamous cases of flight delays, including the plight in 2009 of passengers stranded for nearly six hours on a plane in Rochester, Minn.