European travelers will soon be able to chat it up over their 5G-enabled mobile devices on airplanes without fear of hearing, "Please place your phone in Airplane Mode" from a flight attendant.

A ruling by the European Commission will allow airlines to provide 5G voice calling and high-speed connectivity to the internet in 2023; the decision was quickly heralded as a business opportunity for European companies.

"The sky is no longer a limit when it comes to possibilities offered by super-fast, high-capacity connectivity," Thierry Breton, Eurppean commissioner for the internal market, said in a statement.

The ruling prompted questions about when US airlines might allow 5G connectivity on board their commercial aircraft for voice calls and entertainment.

The US Federal Aviation Administration (FAA) does not prohibit the use of personal electronic devices (including cell phones) on planes. Instead, the US Federal Communication Commission (FCC) leaves the decision up to individual airlines.

In fact, FCC rules allow "any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used."

Therein lies the problem.

Last year, new 5G networks caused interference with older cockpit instruments such as altimeters. Altimeters are critical, especially for landing in low-visibility conditions; they operate at frequencies of around 4.4 GHz.

In the US, 5G networks are rolling out using the C-band - with frequencies between 3.7GHz and 3.98GHz - at the lower-end of the 5G spectrum; that leaves very little gap between the frequencies used by cockpit instruments and has in the past caused interference. In Europe, 5G uses frequencies of 5GHz or above, which is a sufficient buffer between cellular communications and inflight instruments.

That said, with either relatively simple filtering technology or instrument upgrades, C-band 5G transmissions would no longer pose a problem, according to Dan Bieler, a principal analyst with Forrester Research.

"It is up to the airlines to 5G-enable their aircraft. For this purpose, the European Commission has designated certain frequencies for in-flight 5G," Bieler said.

Tom Wheeler, former FCC chairman and now a visiting fellow at the Brookings Institution, told the Washington Post last week that concerns over cockpit instrument interference are largely overblown.

"The reality is that the vast, vast majority of aircraft have altimeters that are shielded from the signals," Wheeler said, and older models are being replaced or shielded.

The International Air Transport Association (IATA), a trade association representing 290 airlines around the globe, believes the "introduction of 5G mobile devices in the aircraft cabin environment is not expected to have an impact in terms of interference with onboard systems."

"In terms of whether use of such devices for voice calling should be permitted, this should be a decision for each individual airline," a spokesman said in an email reply toComputerworld.

Airline passengers cannot make normal 5G calls or surf the Web on a commercial airliner as they fly too high, too fast and over too many remote areas for uninterrupted, quality 5G connectivity.

Over the past two decades, dozens of major airlines began offering paid in-flight Wi-Fi through high-performance air-to-ground antennas located on the base of the aircraft fuselage. The aircraft essentially becomes a Wi-Fi hotspot as the signal is spread throughout the aircraft using a series of access points (routers).

Passengers paying for in-flight Wi-Fi can do everything they would normally would when connected to the Internet, including sending emails,and streaming movies. But that connectivity was based on slower data speeds. Another flaw: the system doesn't work over large bodies of water unless the signal is relayed to a satellite communications system.

Gogo Inflight is one of the most prolific provider of in-flight internet connectivity. The Broomfield, CO-based company supplies more than 2,500 commercial aircraft and 6,600 business aircraft with its on-board Wi-Fi services for entertainment and wireless connectivity.

Gogo's customers include American Airlines, Alaska Airlines, Air Canada, British Airways, Delta Air Lines, United Airlines, and Virgin Atlantic. In October, Gogo announced it had completed its rollout of 5G towers throughout the US.

But airlines operating in the US remain reticent to enable aircraft for 5G communications.

"That's why airlines currently ask you to put the phone in Airplane Mode, which still enables Wi-Fi connectivity, but not cellular," said Bill Menezes, a director advisor at Gartner research.

Without 5G interference issues, there are only two reasons US airlines would be opposed to cell phone use on planes: airlines want to continue selling the exclusive right to Wi-Fi connectivity and entertainment and/or they don't want passengers chit-chatting throughout a flight.

"You get someone who wants to do work and has a cell-enabled tablet or they want to do teams call or something like that, and they can't," said Menezes, who was attending a conference in Las Vegas. "I have people out here who flew out from the East Coast and that's a four- to five-hour flight. That's a lot of time to sit twiddling your thumbs."

There are also benefits to greenlighting the use of 5G communications for the airlines themselves. They can reduce the weight of aircraft, for instance, by removing the entertainment screens on headrests. Some carriers, such as Alaska Airlines, offer brackets on the backs of headrests where passengers can affix their tablets for use with Wi-Fi.

"At this stage, it is uncertain how many airlines will implement 5G connectivity on their airplanes" Bieler said. "After all, an airplane is one of the last few places where one can escape the babbling of many smartphone users.

"Airlines will need to decide what customer experience means for their passengers: the freedom and relative tranquility of a connectivity-free zone or the freedom to remain connected at all times," Beiler said. "If they opt for the latter, airlines might want to consider providing basic rules of smartphone use etiquette."

In December 2021, the FCC proposed access to in-flight mobile services for all fliers, but the decision to let consumers access their mobile devices while in the air will be at the sole discretion of each airline.

In June, the FAA updated its guidance to say  "mainline commercial" fleets should be retrofitted with upgraded altimeters or 5G filters by July 2023, after which the wireless companies are expected to continue rollout of 5G networks near most airports "with minimal restrictions."

The FCC, in an FAQ, noted: "If adopted, ...new rules could give airlines the ability to install an Airborne Access System that would provide the connection between passenger's wireless devices and commercial wireless networks, much like Wi-Fi service is provided today aboard aircraft to provide connections to the Internet and safely manage connections," the agency said.