Since May, passengers on some Virgin Atlantic flights from London to New York have turned on their cellphones in the air, typed out text messages or made calls - without getting in trouble for it.

They're doing what hundreds of thousands of passengers on foreign airlines in parts of Europe and the Middle East have been doing for at least four years: using cellphones once planes have climbed past 10,000 feet. The airlines offer the service to benefit their customers with the blessing of their governments.

But when Virgin Atlantic passengers get within 250 miles of the U.S. coast, the talking and texting stops. The practice is forbidden in the United States because of government safety concerns about cellphone signals interfering with communication networks on the ground and possibly interfering with the plane's communications and navigation equipment.

U.S. airlines also worry that passengers don't want to have to listen to others yakking on their phones when flying.

"Airline customers have commonly opposed in-flight cellphone capabilities because passengers don't want to endure listening to calls from their fellow travelers on a flight," says Victoria Day, spokeswoman for the industry group Airlines for America.

But a new report from the Federal Aviation Administration found no problems -- with either flight safety or noise complaints -- in talking or texting in the air on foreign airlines. The report is raising new questions about whether the U.S. ban on cellphone use is out of date.

Many of the foreign carriers contend U.S. concerns are unfounded.

"There is a misperception out there that it is dangerous," says Patrick Brannelly, spokesman for Emirates Airline, which began offering the service in 2008 and now has it on about 90 of 175 planes. "I think the real fear is people yabbering on the phone at loud volume, annoying people around them. That just simply hasn't happened."

Concerns: Safety and Otherwise

Historically, polls have indicated U.S. airline passengers oppose using cellphones on flights because they don't want to listen to their seatmates' noisy calls.

But that could be changing. Fly.com, a fare-comparison site, this summer surveyed 500 travelers and found two-thirds wanted to be able to talk on their phones.

The Federal Communications Commission has prohibited using cellphones in flight since 1991 out of worries about network interference. Because phones send signals directly to towers, the concern is that planes could shower thousands of calls on ground stations and bog them down.

The Federal Aviation Administration, meanwhile, is concerned that the radio signals that cellphones emit could interfere with a plane's communications, navigation and flight control.

Dozens of scientific reports have warned that radio signals from phones and other electronics can interfere with cockpit instruments in unpredictable ways.

"If it's a nice clear day out and I'm flying, I'm not nervous," says Bill Strauss, an aviation engineer who researched the subject in 2000 for a touchstone doctoral thesis. "If it's cloudy, rainy, bad weather, and the pilot's absolutely got to be sure where he is when he breaks through the clouds at 500 feet, I'm asking the guy next to me to shut his phone off."

Anonymous reports from pilots to NASA's Aviation Safety Reporting System give credence to those concerns. Reports include:

-- The crew of a DC-9 approaching Philadelphia in October 2003 got a warning on an instrument panel saying they were about to collide with a plane less than a mile ahead. After plane climbed from 6,000 to 7,000 feet, air traffic controllers said radar showed no other plane nearby. A flight attendant later said she caught a passenger trying to call her daughter about the time the plane started climbing.

-- A Boeing 737's instruments swung oddly during a flight descending into Baltimore in March 2003, and crew members found themselves a mile off course as they broke through clouds at 1,800 feet. The captain suspected several passengers used cellphones after an announcement about the war in Iraq.

-- The crew of a Bombardier CRJ700 regional jet heard what sounded like a fax machine at repetitious intervals interfering with instructions from air traffic controllers while climbing out of Charlotte in June 2005. After a repeated announcement to turn off cellphones and pagers, devices were turned off and the noise stopped.

The FAA found no reports of cellphones interfering with navigational equipment in its study of their use abroad on foreign airlines.

One advantage the foreign planes have is equipment installed on each aircraft to relay calls to the ground. Each plane basically has its own cellphone tower, which is called a base station, that is designed to avoid interfering with the plane's equipment.

Aboard U.S. planes without base stations, cellphones squawk at their highest power while searching for relay towers on the ground. Higher power means greater risk for interfering with the plane's equipment.

"You're going to be screaming, just like if you and I were far away from each other," says Strauss, the electrical engineer.

But in the foreign planes, cellphones are so close to the base stations that their signals use as little as 1 milliwatt, or one-thousandth as much power as on the ground, according to Brannelly of Emirates.

Foreign airlines and regulators such as the European Air Safety Agency studied the base stations to ensure they are safe for flying.

Aurelie Branchereau, a spokeswoman for OnAir, which provides cellphone service for 14 airlines, including British Airways, says the company works with regulators and airlines to ensure cellphone use doesn't interfere with a plane's electronics.

In the United States, the FCC considered relaxing its cellphone ban in 2004. But it decided against a change in 2007 as airlines, manufacturers and phone companies continued their research.

During the same period, the FAA asked a government advisory group to assemble a committee of experts to study whether using phones or other electronics on planes is safe.

But in 2008, that committee, co-chaired by a Boeing executive, "concluded that the possibility exists that cellphone transmissions have the possibility for interference with on-board systems, like the navigation system," says Bret Jensen, a spokesman for Boeing.

Broad Opposition in U.S.

The opposition to making cellphone calls in the air is substantial enough in the U.S. that the FAA won't consider the issue while it undertakes a newly announced review of what other electronic gadgets, such as tablets, can be used during flights.

"It's annoying and irritating," says Henry Harteveldt, an airline industry analyst who is co-founder of Atmosphere Research Group. "It's bad enough to overhear a noisy passenger talking to her or his seatmate - a tube full of people yakking on their cellphones at 35,000 feet would be enormously unpleasant.'

Many frequent fliers agree.

Jim Pancero, a sales consultant from Carrollton, Texas, says he doubts using cellphones causes technical problems. But after 30 years of flying millions of miles as a professional speaker, he says he hopes the ban continues for the mental health of frequent fliers.

"I can't imagine how noisy and irritating it would be if they allowed phone calls on the plane," Pancero says.

Wide Growth Overseas

Overseas, phone service for talking and texting in flight is expanding rapidly.

The company OnAir provides mobile-phone access to Aeroflot, Air New Zealand, British Airways, Egyptair, Emirates, Etihad in United Arab Emirates, Libyan, Oman, Qatar, Royal Jordanian, Saudi, Singapore, TAM and TAP Portugal.

Another provider, AeroMobile, is now aboard 14 for Thai Airways, four for Virgin Atlantic, two for Gulf Air, one for Malaysian and one for Transaero in Russia.

Five more airlines are committed to joining before the end of the year on a combined 350 aircraft: Lufthansa in Germany, Etihad of United Arab Emirates, Turkish, Aer Lingus in Ireland and Scandinavian. Singapore Airlines has committed to providing the service aboard 20 of its Airbus 350 aircraft due in 2014.

"We believe this is going to be standard in most airlines," says Pal Bjordal, chief executive of AeroMobile. "We believe that concerns once expressed about mobile-phone use and other forms of in-flight connectivity are proving to be unfounded."

The service isn't allowed during takeoffs and landings, and it shuts off hundreds of miles before reaching the United States. The service starts at 13,000 to 20,000 feet, depending on the company.

Text messages are more popular than voice calls. OnAir found that 47% of customers prefer sending texts, 42% checking e-mail and 11% making calls.

"There are probably a handful of people who need to be in touch," says Brannelly of Emirates. "I just put it on and leave it there."

The FAA report, which surveyed airlines about how the services work, found complaints about the cost of service or uncertainty about its availability on some planes. Costs vary. One carrier charges US$12 a minute, though the price typically is about US$2.50 for an average two-minute call.

"The vast majority of use has been to send and receive text messages rather than phone," says Josh Crouthamel, spokesman for Virgin Atlantic, which began offering the service limited to six phones on each plane. "We've received no complaints, and my trolling through the Twitterverse has surfaced nothing but positive comments."