Consumer Federation of California

Airline passengers can use electronic devices in “all phases of flight” if the airline determines that its aircraft can tolerate the interference, the Federal Aviation Administration said, but using a cellphone to talk will still be banned.

The change will most likely take effect before the end of the year, the F.A.A. said. Rules for cellphone use are set by the Federal Communications Commission, and unlikely to change soon, because of the nature of the cellphone system.

The administrator of the F.A.A., Michael P. Huerta, said he expected that, with rare exceptions, airlines would allow the use of tablets, MP3 players and smartphones in “airplane mode,” with their cell network connections turned off. The airlines will have to conduct tests on their equipment and submit the results to the F.A.A. for approval, he said.

Soon after Mr. Huerta spoke, Delta and JetBlue announced that they would submit a plan for passengers to use electronics in flight.

The change would not be universal, Mr. Huerta said. “In some instances of low visibility, 1 percent of flights, some landing systems may not be proven to tolerate the interference,” said Mr. Huerta, briefing reporters in the ticketing lobby of Ronald Reagan National Airport. “In those cases, passengers may be asked to turn off personal electronic devices,” he said.

The rule banning use of personal electronic devices during some parts of the flight “had been in use for 50 years,” he said, and both the devices and airplane avionics had changed in that period.

The change, which the F.A.A. outlined on its website, followed the recommendation an advisory committee made on Sept. 30. For the F.A.A. to approve such a recommendation within a month, which included the 16-day federal shutdown, is unusual; the agency was an active participant in the advisory committee and had been working on the change even before the recommendation was final.

The final document gives extensive detail on what the airlines must test for.

Mr. Huerta stressed that passengers would be told to turn off their electronics when the flight attendants gave preflight safety briefings about what to do in an emergency, and that the airlines would have to develop new rules about stowing lightweight electronics during takeoff and landing.

While flight attendants have no effective way to determine whether a cellphone or tablet is really in airplane mode during flight, Mr. Huerta said, “There’s no safety problem if they’re not, but you’re going to arrive at your destination with a dead battery,” because the device would continue looking for a cell connection and would not find it.

Mr. Huerta said the airlines had generally favored the change, to “enhance the customer experience,” but that they did not have a uniform position. The industry’s main trade association, Airlines for America, supported the decision in a statement.

The president of the Association of Flight Attendants, Veda Shook, said that the change was “welcome news.”

“We’re not going to run away from technology, but we’re not going to run away from safety, either,” she said. Flight attendants would be relieved of the job of making passengers turn off their devices when the plane descended, she said, but would have to enforce new rules about what had to be stored under a seat or in an overhead bin, and what could be held or put in a seat back pocket.

She said she hoped the rules would be uniform across the airlines, to minimize confusion among passengers

And, she said, the old rules were still in force now, although “I’m pretty sure people are going to think they can do this today.”

The new rule applies to all United States carriers. The European Aviation Safety Agency, which participated on the F.A.A. review panel, said Thursday it would analyze the American decision before clarifying its own policy.

“The position the F.A.A. announced today is actually a step in the direction of the way it works in Europe,” Dominique Fouda, a spokesman for the European agency in Cologne, said in an email. In Europe, he said, “there is per se no ban” on the use of mobile phones and other personal electronic devices. Rather, it is the responsibility of the airlines to demonstrate that they do not interfere with cockpit equipment.