May 23rd, 2013
We all usually have had to shutdown our electronics devices when flying. This is usually limited to takeoff and landing when instrumentation is key. Not to touch on the technical nature too much but radiofrequency (RF) signals are used in many aspects of flight and pilots use instrumentation that use these signals to operate the aircraft in a safe manner. The operator (airline) is in charge of allowing/denying Personal Electronics Device (PED) use [14 CFR 91.21] except cellphones which are prohibited [47 CFR 22.925]. Most airlines restrict PED use during takeoff and landing. Currently the FAA is looking at relaxing that regulation [FAA-2012-0752]. Prompting this could be any number of things: passenger complaints about not being able to use their devices or PED manufacturers that want their equipment used more etc.
Electromagnetic Compatibility (EMC) is the study and regulation of both what is called susceptibility/immunity (how sensitive something is to electromagnetic interference) and interference (what a device produces electromagnetically). There are all kinds of standards like FCC (USA) CE (Europe), RTCA (Aircraft), MIL-STD-461 and many more. These standard set levels of electromagnetic interference that a device like a PED are allowed to put out and how much interference aircraft equipment can take before disrupting it’s operation. These standards are discussed and revisited constantly based on many criteria such as FAA incidents, new technologies, new aircraft type (i.e. the new Boeing 787 prompted a new standard because of the carbon composite fuselage) etc. And PEDs are not the only items which standards are addressed. For example, as a passenger, your plane may be hit by lighting. So there are tests and standards to see if equipment is susceptible to a lightning strike to a certain level. None of the testing ensures 100% safety but the standards attempt to address issues that can affect safety and changing technologies.
The increased desire for passengers to use PEDs is one of those changing technologies. It is a difficult problem. There are some documented instances where PEDs cause issues on planes which jeopardizes the safety of the plane. But, you just do not know what harm they can cause and it is better to err on the side of safety. We can set equipment testing to a higher standard but some of the equipment uses frequencies and therefore there is really not much you can do about the susceptibility. One possibility is to require qualification of PEDs for airline use. That would be unpopular because it would increase the cost of the devices. Just taking the stance that PEDs should be allowed because of demand is not a valid approach, though. It should be investigated using scientific methodology. The FAA does a somewhat fair job trying to mediate demand with scientific principles. They take public comments, industry insights and more. The investigations will always continue as the types of wireless devices and pervasive use increase. Anything can happen, a device can break and operate abnormally, devices can interact with each other and much more that can jeopardize safety. Insurance should look at increasing the rates to airlines that allow PEDs to be used during takeoff and landing. You can even pass the cost off to the individual passenger that can not live for the ten minutes or so without their device.
Some other references
Ronald Kollman – RF Hardware Designer and President of Haynes-Bent, Inc.
Haynes-Bent, Inc. – Radiofrequency (RF) hardware design, EMC/EMI analysis and 3D Electromagnetic simulation. We also provide Technology advise for investors and executives.
Copyright © 2013 – All rights reserved. May not modify. May only link to the published page – Haynes-Bent, Inc & Ronald David Kollman