by Harold Green
In recent years, the advent of “Portable Electronic Devices” (PEDs), such as the iPad, have produced a wave of such devices in the cockpits of general aviation aircraft. These devices offer not only navigational information, but also can provide a link to radar weather and current AWOS/ASOS information. On some applications, flight gauges are also presented. Real-time positional tracking – accurate enough to show the aircraft’s position on sectional charts, approach plates and, even on airports with detail sufficient to provide taxi guidance – are all available. These devices can contain a directional and attitude gyro, and GPS receiver. In addition, they can include the aircraft Pilot Operating Handbook (POH), weight and balance data, etc., etc. Also, connection to the Internet is available through various means.
As might be expected, other new products are becoming available in competition with the iPad as their use, and therefore, the market, expands. The devices themselves are purchased for less than a one-year subscription to commercial full U.S. “paper” approach plates. Software subscriptions are available at very reasonable prices.
There is no question but what these devices provide a significant aid to pilots and to aviation safety if used properly. Integrating these devices into the regulatory environment is an interesting issue. We will discuss an overview of the situation and then go into some practical details.
Often questions arise as to whether or not a “paper backup” is required when the devices are in use. The answer is, No – a backup is not required! Remember the issue here is legality, not common sense. More to be said on this subject later. The most difficult question really is: Are these devices legal for use in aircraft? The answer is “Yes,” if you are flying VFR. If you are flying IFR, the answer is “Maybe.”
The cover regulation for this is FAR 91.21d. PEDs are legal under IFR if the operator has conducted appropriate testing of the device in use. If you are operating under FAR Part 91 (non-commercial), under most provisions you can conduct those tests yourself, providing you comply with the pertinent provisions of Advisory Circular 20-176 and document that fact. If you are a commercial operator, or are operating under FAR 91F or 91K, you must conduct those tests AND receive the blessings of the FAA. Later in this discussion, we will look at a few of the test subjects.
The question also arises as to the penalty for non-compliance with the provisions of 91.21 and AC 20-176. The answer is probably nothing from a legal standpoint, unless you are involved in a rules infraction or an accident. However, there is a broader issue involving flight safety due to equipment interference or, more likely, pilot distraction due to lack of training.
We will discuss only those operations conducted under allowable provisions of FAR 91. For those looking for further official guidance, reference should be made to FAR 91.21 91.103 and 91.23, as well as Advisory Circulars AC 91-21, AC 91-78 and AC 20-176. A quick call to your FAA Flight Standards District Office will produce a list of very helpful documents.
If you decide to explore this issue further, it would be useful to keep in mind that the customary route for approval of electronic equipment for flight is to ensure that the design has been tested to conform to FAA standards, and that quality control to rigorous aviation standards is applied to the manufacture of the device. Further, software development and quality control is covered by RTCA document DO-178. This document provides the FAA with assurance that the designs initially, and throughout manufacture, meet FAA standards, including the design and transfer of software. The devices under discussion herein have not been designed, nor are they manufactured in compliance with those standards. That does not mean they are of poor quality, either in design or manufacture. It simply means that the FAA – to perform its mission – must find other means to assure that its standards are met.
Now we will consider some of the requirements spelled out in AC 20-176. By no means is this a complete list. The subjects are some of those included in AC 20-176 and which I have found to be particularly relevant in day-to-day flight training operations involving the use of PEDs and Technically Advanced Aircraft (TAA), or glass cockpit-equipped aircraft.
Pilot training is an area of concern listed in AC 120-76. Working with a portable device somehow doesn’t receive the same attention that a panel-mounted unit does. Yet, all too often student pilots struggle with the proper sequence of events to load and view an approach.
There are two areas in which electronic devices – be they glass cockpits or PEDs – challenge pilots. First, the rapid loading and selection of initial fixes of an approach, and the selection of a different approach than that planned. With paper, the issue is simple: Just flip to a new page and/or select a new Omni Bearing Selector (OBS) setting. With the electronic devices, this is not so simple because several button pushes and decisions are required, and a mistake can create the need to start over. The airplane does not stop while you do this. For both the PED and the glass cockpit, pilots should train themselves to access and modify information rapidly and without error.
A very good test is to be executing an approach and, while in the missed approach segment, rapidly select a new airport and a new approach without disrupting the missed approach sequence being executed. While this is unusual, it is not unheard of and provides an excellent training sequence.
A Flight Training Device (FTD) is an acceptable means of accomplishing this, provided the exercise is under the guidance of an instructor. In short, pilots should be competent in the operation of the PED in all foreseeable circumstances before betting their life, and those of their passengers, on the outcome. Remember, for Technically Advanced Aircraft, if the need for the PED as a backup materializes, the pilot is already in a stressful situation.
Flight crew workload deals with the positioning and use of the PED to reduce pilot workload. In most cases, we operate as a single-pilot crew. Turning your head back and forth while simultaneously reading the flight gauges and operating the PED produces an increased probability of “vertigo.” It behooves us to place the PED in a position where it can be viewed readily, with a minimum of head movement, particularly from side to side. Further, minimizing the eye movement required to go from panel to PED should also be considered. As a final comment in this area, learning to dim the PED display for night flight prevents night vision from being impaired. It goes without saying that a mounting technique that eliminates the possibility of the device falling from its mount is a good thing!
Batteries: For devices that have no aircraft power source, a backup battery may be required. The FAA recommends a battery capacity of twice the flight time. If battery capacity is less than this, a backup battery is recommended. A second PED can be considered as a backup, provided it has sufficient battery capacity. Lithium batteries require careful handling and it is strongly recommended that the provisions spelled out in AC 120-176b, 11. b, c, d, e-1 thru 7 be followed as these batteries have the potential to create fires, and even under some conditions, can explode.
If you leave the PED in the airplane out on the ramp, the temperature that your device is subjected to in an airplane may well be beyond the manufacturer’s design limits.
There is no requirement to have a backup except for battery capacity. But remember, there is a requirement to have up-to-date data available (i.e. non-expired approach plates). That means you must have the latest data revision loaded into the PED for all software elements contained in your PED. This means that if the POH is in your device, it must have the latest revisions also.
It should be obvious that some form of backup is a good idea. As equipment becomes more complex, it is also more prone to failure. We will all agree that the consequences of a failure in Instrument Meteorological Conditions (IMC) can be severe. Therefore, having a backup is only common sense.
If your aircraft is equipped with a glass cockpit, then your PED becomes a very viable backup because it is independent of the primary system. Of course you must check the batteries for life and charge. Whatever form your backup takes, it should be a) Independent of the primary device, and b) Preferably of dissimilar technology. While the PED and the glass cockpit are both electronic, they are of different manufacturers and source. If you have steam gauges, then it is suggested an excellent backup to the PED is “paper.”
Finally, how do we begin to comply with the test requirements? Basically, use it in VFR and watch for interference with the navigation systems of the aircraft as you turn the PED off and on. While the FAA has not blessed this, I suggest it would be reasonable to document your observations just like you do with the 30-day check on your VOR accuracy.
One standard set by the FAA Flight Standards District Office for commercial use is for 25 flights under VFR before the unit is approved for use in commercial operations. Also, note that the PED must contain the full information from the approach plate.
EDITOR’S NOTE: Harold Green is a CFII at Morey Airplane Company at Middleton Municipal Airport – Morey Field in Middleton, Wisconsin (www.MoreyAirport.com).