As regulatory agencies in Europe and North America grapple with whether to permit the use of personal mobile phones in flight, the companies that intend to sell and market the services not surprisingly are trying to convince the world that the concept is perfectly safe, will not foster air rage as some have claimed and that the concerns in general have been overblown.

A number of newspaper and magazine articles in the general press have focused on the social aspects of cellphone use in the cabin, touting the results of various surveys that show passengers by and large want current bans on this type of activity to remain in place. What these articles rarely point out, however, is that the surveys in many cases were commissioned by flight attendants’ unions, which don’t want their members to have to deal with angry cellphone-wielding passengers.

A recent FCC notice calling for comments on proposed rulemaking received thousands of comments in support of the current cellphone ban, but fewer than 100 were technical in nature. Many of the rest appear to have been solicited directly by flight attendant unions whose members are demanding the restrictions remain in place, said Timothy Shaver, an FAA transportation analyst in Washington.

Interestingly, he said the FAA agrees with flight attendants who worry about the potential for cellphone-related incidents to detract from their ability to do their jobs, saying it’s an area that has been getting a lot of attention lately. “The social issues of allowing cellphone use are much harder to address than the technical issues and might ultimately be the deciding factor on this issue,” he said.

Echoing that sentiment, the FAA’s associate administrator for safety, Nicholas Sabatini, recently told a House aviation subcommittee that the agency is concerned that flight attendants will be distracted from their “critical safety duties” if they have to deal with passengers irate over the fact that their call didn’t go through, or that the passenger sitting next to them placed a call that did go through.

Among business jet travelers the social issues shouldn’t factor into the discussion much since the only person whose opinion normally matters is the CEO or other VIP on board. But there continue to be important technical questions about cellphone use after takeoff, and the debate is heating up. AIN ran a front-page article in May that discussed the findings of a Carnegie Mellon study that found cellphones can pose a danger to onboard electronics.

Coming to a Cabin Near You

The FAA has commissioned the RTCA to study the technical issues surrounding such activity in flight, work that is scheduled to be completed by the end of this year. In Europe, where experts say the telecommunication regulatory framework is simpler, Air France will soon begin trials of airborne mobile phone service aboard an Airbus A318. Depending on your viewpoint, it’s a serious issue complicated by countless unknowns or it’s misguided hysteria based on hype rather than the facts.

OnAir, a joint company owned by Airbus and SITA, is behind the effort to bring mobile calling capability to Air France airplanes. (In addition to OnAir, a company called AeroMobile formed by Telenor and Arinc is developing the technology.) George Cooper, OnAir’s CEO, said Europe is the company’s initial target but that it plans to extend the service around the globe. As a result, OnAir pico cell technology must be able to manage almost a dozen different cellphone standards. The first version of the technology, however, will manage the three ground-network standards in Europe, two of them being GSM-based and one a variant of CDMA.

“This will be sufficient in our view to prevent interference with ground networks, which is what then triggers the potential problem on the aircraft for avionics,” Cooper said. “As long as we’re controlling the networks that are present we won’t have any problem with networks that are not.”

A passenger trying to use a cellphone on an airplane will be successful placing
a call only if the phone is capable of operating over a network within range. If
the phone operates in European GSM or CDMA, the onboard pico cell will manage its power level, telling the phone to go to its lowest setting to prevent interference with onboard systems.

If the phone uses some other standard, say North American CDMA, it won’t detect any usable networks and will quickly revert to low power, Cooper said. He conceded that such a phone would broadcast at relatively high power if the passenger continued trying to use it, but said passenger education will be part of the process of bringing the technology to commercial airplanes.

“The incidence of non-European devices on the aircraft and the chance that all of those people would be switching them on at the same time is reckoned to be extremely low based on the research that’s been done,” he said. “Given that today up to 10 percent of devices carried onto aircraft are in fact left switched on in any case–sometimes deliberately, sometimes inadvertently–this is a situation that will be no worse, and indeed will be better because of the control of the vast majority of
the devices on board.”

But what if the pico cell technology on the airplane fails, unbeknownst to the crew? Such a possibility is of major concern to regulators, who must grapple with the chance, however remote, that failure of the system tasked with managing call traffic could create a dangerous situation.

In December 2004 the FCC issued an NPRM that would effectively lift the ban on cellphones and other personal electronic devices, as long as they operate under the control of a pico cell installed in the aircraft. A pico cell is a special, smoke-detector-sized transmitter designed to collect wireless signals from airborne cellphone calls and transmit them directly to a specialized ground-based cellular network or a satellite network.

Pico cell systems are equipped with a control panel that would allow the flight crew to control the type of communication services allowed. Flight attendants will be able to disable calls during certain phases of flight, such as on takeoff and landing or at night, and will likely ask passengers to keep their phones in vibrate mode at other times.

Without a pico cell, airborne cellphones would normally operate at their highest power setting in an attempt to reach base stations located far away on the ground, potentially causing interference to ground-based cellular networks. For example, signals received from an airborne cellphone at 100 miles from a ground-based cellular base station (assuming line-of-sight) will generally be 100 to 10,000 times stronger than signals received from a ground-based handset 100 miles away, research shows.

Installation of a pico cell on the aircraft would alleviate the problem of cellphone callers connecting directly with towers on the ground. But let’s say the system fails without warning and passengers continue trying to place calls. Flight attendants normally should receive a warning that the pico cell system is not functioning properly, but they might not in every conceivable instance.

Cooper said passengers flying aboard aircraft in the en route phase would likely not be able to place a call if the pico cell were to fail and so they would give up trying. During approach and landing phones must be switched off whether the pico cell is functioning or not, meaning the danger would be no more real than it is now on airplanes that aren’t equipped with pico cell technology. In any case, the aircraft manufacturer has already performed hundreds of hours of testing to ensure the concept is safe and is satisfied with the results, he said.

“Airbus [with its fly-by-wire flight control systems] well understands the issues about electronic emissions on and out of its aircraft,” Cooper said. “It has had to deal with it for decades, and so we’re in the hands of real experts who do know what they’re doing. I would say it is highly unlikely that Airbus would be prepared to put a system on its aircraft on the production line if it wasn’t completely happy that this is a completely safe thing to do.”