Hvorfor du må slå av mobilen under flyging forklart her - Curt Lewis

 Why You Need to Turn Off Your Cellphone When You Fly

David Slotnick has a confession: Even though he writes about aviation and air travel, he has occasionally neglected to turn off his cellphone while flying. “I forget,” he admits. “Plenty of people forget.”

Slotnick, who works for the Points Guy travel advice website, may soon be getting extra reminders. Concerned about risks from new cell service, the Federal Aviation Administration (FAA) has asked pilots to emphasize to passengers the importance of turning off cellular devices or putting them in airplane mode in flight. The agency may even limit bad-weather landings at some airports due to safety concerns. 

Although a cellphone has never definitively been shown to have caused a plane crash, airlines prohibit their use in flight because of the small chance that radio waves might disrupt safety equipment. Now there’s a new worry: that expanded 5G cell service, scheduled to come online in January, could make the problem more likely.

The new 5G service, which provides faster downloads and data connections, is already available and in use around the country, but this would represent a significant expansion because it operates in a different spectrum.

“It’s probably safe, but the FAA is insistent that it has to be proven to be safe,” Slotnick says.

The FAA’s concerns

The federal agency issued a bulletin in early November warning that the new 5G spectrum, called C-band, operates at frequencies near ones used by cockpit radar altimeters, which measure an airplane’s distance from the ground. The Wall Street Journal reported that the FAA may tighten standards at dozens of airports where high-frequency cell towers are located near runways. That could slow air traffic or even lead to flight cancellations in bad weather.

The Air Line Pilots Association applauded the FAA announcement and urged the Federal Communications Commission (FCC) — the agency that regulates the allotment of radio spectrum and had approved the use of 5G — to work out a safe solution with the U.S. cellular industry. Two congressional leaders, Reps. Peter DeFazio (D-OR), chairman of the House Committee on Transportation and Infrastructure, and Rick Larsen (D-WA), chairman of the Subcommittee on Aviation, have also urged the FCC to conduct a "robust risk assessment" before moving forward. "In aviation, we never roll the dice with safety," the members wrote in a letter to FCC Chairwoman Jessica Rosenworcel.                                                  

Major cell carriers Verizon and AT&T have already delayed their planned 5G expansion from early December to January in response to the FAA’s questions. Other carriers, including T-Mobile, aren’t as affected because most of their 5G service operates in a different spectrum that is of less concern to the FAA.

Assessing the risk

The cellular industry insists there’s no danger, and has even launched a website, 5GandAviation.com, to calm fears. It notes that 5G is being used in nearly 40 countries without reported problems, and has been studied for years by U.S. regulators and others around the world.

“5G networks using C-band spectrum operate safely and without causing harmful interference to aviation equipment,” Meredith Attwell Baker, president and CEO of CTIA, an organization representing the U.S. wireless communications industry, said in a statement. “Any delay in activating this spectrum risks America’s competitiveness and jeopardizes our ability to ensure global 5G leadership.”

However, engineers say the risk is real. “The lack of an accident does not mean safety,” says Al Secen, vice president for aviation technology at the Radio Technical Commission for Aeronautics, which develops standards for airline safety equipment and issued a report raising concerns about 5G interference. “This is a very serious thing.”

Ludovic Chung-Sao, who has worked on airline parts certification with the FAA and its European counterpart, agrees: “A safe flight depends on many flight instruments that also work with radio frequency communication. Wrong information on the flight instruments can lead to confusion in the cockpit, which can have a catastrophic impact. Would you risk it?”

Still, even if 5G rolls out, Secen says he would get on a plane in January, expecting he could be more likely to face weather delays and cancellations. “I would feel safe getting aboard,” he says. “The industry is built around safety, and it will do what it takes to maintain safety.”