Updated to include comment from Honeywell.
Imagine you are playing on your iPad or using your smart phone whilst seated in an aircraft that is barrelling down the runway at 130-155 knots. Suddenly the takeoff is aborted, and the aircraft comes to a screeching halt. Your iPad, as well as the personal electronic devices (PEDs) in use by all the other passengers on board the aircraft, could become projectiles.
“Plastic water bottles, magazines and paperback books flying around the cabin during a rejected takeoff can certainly cause damage but not serious damage. Now consider what happens when you add hardened devices, like iPhones, iPads, and laptops; they are more ruggedised and have more mass so that presents a greater danger,” says inflight connectivity expert Michael Planey.
This is one of the key issues that the US Federal Aviation Administration (FAA) will have to consider when it convenes a working group to determine if passengers really need to turn off their PEDs during takeoff and landing, and should it ultimately decide to provide guidance to airlines on how to approve PEDs to run during those periods. “There is a certain amount of risk in letting these things be used during takeoff in particular,” says Planey.
But PEDs-as-projectiles is not the only consideration for the FAA. The agency has long recognised that PEDs have the potential for causing electro magnetic interference (EMI) with aircraft navigation or communication systems on board aircraft. The issue has received heightened attention in recent years because a certain type of avionics, specifically Honeywell Phase 3 Display Units – which are present on various Boeing 737NG and 777 aircraft – proved susceptible to blanking during EMI certification testing of wireless broadband systems.
As a result, operators of 737NG and 777 aircraft with Phase 3 DUs that wanted to offer inflight connectivity to passengers had to place placards in the flight deck saying that transmitting PEDs (T-PEDs) must be powered off. A bevy of airlines currently placard their cockpits as a condition for receiving supplemental type certification for inflight connectivity systems. Additionally, Boeing stopped linefitting connectivity systems to its widebody aircraft.
Resolving the Honeywell issue has taken far longer than anyone thought. Honeywell is understood to have tabled previous fixes that didn’t remedy the problem. But Bret Jensen of Boeing Commercial Airplanes’ engineering communications unit says Boeing and Honeywell have since “developed a change to the Phase 3 Display that addresses the susceptibility issue”.
The new ‘Phase 3A’ DU will be delivered on both 737 and 777 aircraft by the end of this month. And Boeing and Honeywell service bulletins for retrofit will be released soon after production incorporation, he says. Asked why the process took so long, Jensen says: “We have to be thorough in the testing and assure that all criteria are met in order to ensure certification. Sometimes schedule is compromised.”
Honeywell director of worldwide external communications Christopher Barker says: “Flight safety is a top priority for Honeywell. To clarify, one cockpit display screen in a 737 blanked during an STC ground test in late 2010 when exposed to several times more power than it would experience in normal operation. The development test occurred on the ground and was intended to measure wireless device impact in the cockpit. No display units have ever blanked in flight since these displays entered service more than two years ago. We will be releasing the new version of the Phase 3 DU hardware in 2012 and will field the new units in early 2013.”
It’s somewhat ironic, perhaps, that T-PED testing on many older aircraft show virtually no EMI issues, whilst new-design avionics have encountered problems. “It’s true that as the cockpit avionics become more sophisticated, more digital in nature, we’re having to pay more attention to EMI,” says Thales Avionics VP marketing and customer proposition Stuart Dunleavy.
But, when it comes to EMI, the susceptibility of onboard systems is not the only concern. “One of the big issues that [the FAA working group is] going to have to tackle is that passengers could come aboard with modified PEDs,” says Rich Salter, chief technical officer at inflight entertainment firm Lumexis, and a member of the Airline Passenger Experience Association (APEX) technology committee.
“So, for instance, let’s say the FAA issues guidance on how to approve PEDs to be used during this period below 10,000ft and the airline goes out and tells passengers that certain devices are approved. How do they know if devices have been repaired and if the repair technician has put the EMI shield back on correctly? The whole idea of modified passenger devices – devices that have been opened up and repaired – opens up the question of whether the device has been put back together correctly. To me that’s the real tough nut. Even dropping some devices can jar the EMI shield loose; you can visualize how things like that could happen,” says Salter.
Some industry observers suggest that if EMI with avionics was a serious problem the FAA would not have started allowing pilots to turn on their iPads during takeoff and landing as part of airline electronic flight bag programmes, and flight attendants would be expected to check each and every passenger PED before takeoff. This inconsistency received national attention after actor Alec Baldwin was kicked off of an aircraft for refusing to shut down his device before takeoff.
What gives Planey pause, however, is the fact that new PEDs with Wi-Fi, WiMax, “and all different connections to the world” are being rolled out at an astonishing rate, and he doesn’t know “if it is possible for all authorities to keep up with whether or not adequate testing has been done”.
“Is any one individual device in its manufactured form likely to cause a ton of interference or danger? The answer is no. But there is a multipliable effect of having 75 devices at one time, even in their lowest power settings, and it’s somewhat difficult to replicate all of its possible iterations. You can end up with combinations of things in the real world you don’t necessarily come up with in the lab.”
Beyond the issue of EMI, there may be justification to having people put their devices away, particularly before takeoff during safety announcements. However, theoretically, airlines could allow passengers to turn on their PEDs directly after the safety announcement, “which would be especially useful to passengers who are stuck on a runway, or on climb out to 10,000ft. It would be nice to be able to use PEDs during that time,” says Lumexis’ Salter.
If the FAA lifts its current ban, the move could prove to be beneficial to inflight connectivity companies. Recovering the time spent below 10,000ft would allow for greater revenue generating potential, especially on short- and medium-haul flights.
The FAA is accepting comments from the public about the use of PEDs on board aircraft for a 60-day period, which began on 27 August. JetBlue Airways, which is readying to fit its fleet with a LiveTV/ViaSat Ka-band satellite-supported inflight connectivity system, and Virgin America, which offers the Gogo air-to-ground connectivity system, say they are pleased the FAA is initiating this study, as reported by The New York times.
After all comments have been collected, the FAA intends to establish the working group – called the Aviation Rulemaking Committee (ARC) – to review the comments and provide recommendations that might permit the more widespread use of PEDs during flight. The FAA says the FCC will be a key partner in this activity, working collaboratively with the FAA, airlines and the manufacturers.
To wit, the APEX TC committee has already agreed to support the FAA study. Rich Salter and well-known industry consultant Michael Childers will serve as liaisons from the TC, and other APEX members are likely to be involved as well, most especially because many are sitting on a vast amount of T-PED test data after implementing inflight entertainment and connectivity programmes with airlines.
“We’ve got the expertise of all the supplier companies in our group, and the airline expertise as well, and so I think the TC is uniquely positioned to bring some of the information that the FAA needs to this working group,” agree Salter and Childers.
However, even with these studies, Planey is not convinced the FAA will instigate dramatic changes to onboard PED usage in the near term. “I don’t expect this to be a particularly speedy process. The FAA moves at the speed that is understood and established in the industry and I don’t think this issue will make them move out of their normal pace.”
“The FAA is perfectly justified in erring on the side of caution,” he adds.