In-flight electronics get the OK

The regulator now accepts that most commercial aeroplanes can tolerate radio interference signals from devices such as e-books, tablets handheld gaming systems and wireless keyboards. The majority, we suspect, will be relieved that voice communication using mobile phones will continue to be banned during a flight but, in truth, the advisory group established last August by the FAA and which reported on the last day of September was never going to change that restriction. Not least because the use of cellular frequencies is the domain of another US regulator – the Federal Communications Commission. The upshot is that passengers with PEDs – even smartphones – will be able view from 'gate to gate' any book, film or clip downloaded before the flight. Previously, PEDs could only be operated once the plane reached 10,000ft – but they will still need to be operated in 'flight mode'. Passengers could potentially have Internet access during the entire flight, but only through the carrier's (usually very expensive) Wi-Fi service and not via their cellular network. However, not all in-flight Internet providers are optimised to offer the service beneath 10,000ft. Those relying on cellular services and towers will not, while satellite based providers, who have, to date, not been allowed to switch the service on, will now be able to do so. Most will ask why this decision took so long? And why all the inconsistencies? There is no smoking gun here: there is no definitive proof that an air accident has ever been caused by, or attributed directly to, a passenger's use of a PED. Some sceptics are likely continue to argue that we must not rule out the possibility of EMI altogether, but those who have for years ignored the rules – wilfully or accidentally – will feel vindicated. Surprisingly, the normally ultra cautious FAA took just four weeks to accept the bulk of the recommendations made by the 28 member PED Aviation Rulemaking Committee (ARC). However, the FAA has left it to individual airlines to determine when to implement the changes, once they have proved to the FAA that their fleet can tolerate PEDs' potential EMI. Most are expected to achieve this by the end of the year, but two – Delta and the smaller JetBlue – took just hours to submit plans to comply with the new regulations. One complication for international passengers is the lack of harmonised regulation, but regulators in other countries have started to scrutinise the FAA's rules and assess the knock on impacts. "We will be discussing the FAA's recommendations with the European Aviation Safety Agency (EASA), which has oversight throughout the continent, and expect to reach a unified response," Richard Taylor, a spokesman at the UK's Civil Aviation Authority (CAA) told New Electronics. "We hope to reach a final decision as quickly as we can," said Taylor, adding that each airline will still need to make a safety case. In an e-mail, a spokesman for the Cologne based EASA noted 'the position the FAA announced is actually a step in the direction of how it works in Europe: there is, per se, no ban on the use of PEDs … if the airline can demonstrate that aircraft systems are not affected'. Just days before the FAA's announcement, in an e-mail exchange, the CAA told New Electronics 'it would possibly not be prudent for us to carry out a similar consultation, due to the possibility of divergent recommendations which (would) exacerbate the problems experienced by passengers today'. Like other European regulators, the CAA has not done any significant testing since 2003 to ascertain how RF emitted by a device such as a mobile phone could interfere with an aeroplane's avionics or navigation systems. But work has been done with industry committees to understand the issue better; organisations such as Eurocae (in Europe) and the US Radio Technical Commission for Aeronautics (RTCA) have formed working groups to look at the issues caused by PEDs and to establish means by which the threat of interference can be characterised and processes developed to test aircraft, should an operator wish to determine if their aircraft is tolerant to the threat ...'. The CAA added: "Airlines and regulators need evidence that the simultaneous use of numerous PEDs during take off and landing will not endanger an aircraft and that the processes to prove 'safe use' or identify areas of susceptibility that then need to be addressed are now in place." More activity in the US In the US, there has been more recent activity. From 2003 to 2006, the RTCA considered the potential impact of EMI from intentionally transmitting PEDs, including Wi-Fi built into laptops, but concluded there was not sufficient evidence to change the FAA's guidelines introduced in the 1990s. It did, however, come up with recommendations as to how the industry could assess the risk of interference, as well as guidelines for certification of PEDs. One of these, dubbed DO-307, provides the test methods deemed necessary to verify both avionic system RF immunity for intentional transmitting PEDs and the interference path loss for PED spurious RF emission. Speaking to New Electronics just days before the FAA's ruling, Dave Carson, an associate technical fellow at Boeing focusing on EMC tolerance in aircraft and cochair of one of the RTCA's key subcommittees (SC-202), said: "The FAA will probably have to do something and relax the rules. It is under huge pressure now, but this troubles me. With airline safety, you should err on the side of caution." He added that, even if an aircraft passes the rigorous criteria of DO-307 –including tests on all signals that can get into the avionics and wiring and establishing immunity through all the doors and the results indicate the aircraft's systems and operations are tolerant to PEDs through all phases of flight – there are still other reasons to turn these devices off during take off and landing, for instance paying attention to safety announcements. Emissions from PEDs leak out of planes through windows, doors and hatches and could degrade the signals being received by the antennae mounted on the aircraft's fuselage, added Carson. And the danger is not just emissions from transmitting PEDs, but also from the clocks and oscillators in PEDs and mobile phones that may be poorly shielded and allowed to radiate – something that may be more of a problem with devices from manufacturers at the very low cost end of the market. DO-307, and its European equivalent ED-130, specify test methods to verify avionics system RF immunity for intentional transmitting PEDs and to verify interference path loss for PED spurious RF emissions. Carson emphasises that engineers at Boeing's test facilities in Seattle have put a variety of PEDs and mobiles through their paces in an anechoic chamber 'and have certainly found that some have the potential to interfere and that some hidden signals were more than what we would consider to be an acceptable limit for some older type of aircraft'. The worst offender was a popular tablet, although some top of the range mobile phones also exceeded prescribed limits. "Modern planes are, of course, built with portable electronics in mind and are hardened against EMI," said Carson, "but I remain on the cautious side." To be fair, there have been cases of pilots reporting electronic devices interfering with flight systems – and, in most cases, the navigational or operational anomalies subsequently disappeared when the culprit was located on the flight. Meanwhile, NASA has been compiling data and continues to publish reports on PEDs alleged to have had 'critical' effects on systems on board. But – and here is the crunch – these happened during critical stages of a flight, specifically take off and landing. The NASA database, based on voluntary submissions by carriers of safety incident reports, covers not only avionics and navigation systems, but yaw dampers, engine fuel controllers, speed brakes and auto throttles. In all cases, the systems checked out fine once on the tarmac. It's likely that would not have been much of a surprise to engineers at EMT Labs, the Californian EMC test house. "PDAs just don't generate sufficient interference to cause problems on a modern plane. We tested a Kindle being used and it emitted just 30µV/m of electrical interference. Other devices we test generally show 80mV/m," Jay Gandhi, EMT's ceo told New Electronics. FAA regulations specify a plane must be able to withstand 100V/m and most planes these days are immune to 200V/m, he added. He also refuted suggestions by the FAA and some airlines that hundreds of PEDs would have a multiplying effect. Gandhi stressed electromagnetic energy does not add up like that: for instance, five Kindles will not emit five times the energy of one Kindle. Amazon itself says it has tested a plane load of online Kindles in flight and pronounced there were no interference issues. Drew Herdener, a company spokesman, told New Electronics: "We have been fighting this issue for years. This is a big win for customers and, frankly, it's about time." Clearly, it is a big win for Amazon as well. His colleague Paul Misener, Amazon's vice president of global public policy and chairman of the ARC technical subcommittee, said that because they are now so resilient to EMI, 'the vast majority of aircraft are going to be just fine' from a safety standpoint. Misener also suggested the FAA's proposed system for testing PEDs would, to a great extent, be based on reassessing earlier test results, rather than having to conduct a battery of new tests against new specifications. He is also quoted as suggesting the industry can 'rest assured' that gate to gate use will pose no threat to passenger safety. Talking with New Electronics, Carson's riposte was 'people who comment with that degree of certainty are obviously talking from their own perspective, do not know how aeroplanes operate and do the general public a disservice. It is presumptuous to say that all new planes in all circumstances will be fine – it is just too broad a statement'. So the long and heated debate is likely to continue, at least amongst those in the industry. As for passengers, the focus can now shift from occasional bust ups with air crew regarding PEDs to those other gripes amongst air travellers: lost luggage and the quality or existence of in flight meals.