EFIS -- A Challenge for the FAA
© E. R. Martin1
NB: This was written in 2011. In the ensuing years FAA district offices changed their tune and adopted much of what is suggested here.

Fatalities due to loss of instruments in IMC could be avoided by installing "experimental" EFIS units2 ($2500 with over an hour of battery backup) on certified aircraft. But the FAA does not generally allow it3. I am considering an effort to get the FAA to examine these units and issue a blanket approval that would allow such installation for reference and backup purposes only. The draft letter below, intended to go across the chain of command of the FAA, makes the pitch. Any suggestions you might have would be most welcome.

Dear _______________:

Lives are lost every year when aircraft in instrument meteorological conditions (IMC) impact the ground after losing their instruments due to engine or electrical power failure. Now, breakthrough technology has resulted in inexpensive instruments which can save virtually all of these lives. With no downside. In a perfect world, the FAA should be encouraging such instruments aboard certified aircraft as backup units. Instead, because the instruments are for experimental aircraft (i.e., they are not certified), the FAA generally does not allow it.

I am seeking your help in reversing this. At this point, all I want is for you to look at this subject, not act on it. I believe that when you assess this matter, you will not only conclude that it is a no-brainer, but your conscience will urge you to act. Incidentally, I have worked on FAA programs (see footnote 1) and no one is suggesting that it will be easy.

First, you need to know that I have no financial interest in this. I'm an engineer with 30 years experience in satellites and aviation who sold his company, was able to retire early and then satisfied a life-long desire of becoming a private pilot. And my interest is not even personal, since I am a VFR-only pilot.

Second, you need to take a look at a harrowing IMC fatal accident to feel a great sense of despair. One such accident (click for details) occurred in November 2004. In it, the pilot of a single engine Cessna P210 in IMC starts losing the engine at 19,000 feet. Despite substantial and effective assistance from ATC for a prompt descent, the pilot loses all engine power, loses his instruments, reports "difficulty maintaining control of the airplane in this IMC" and soon loses his life when the aircraft impacts the ground. Without vacuum for his standard instruments, maintaining directional control in IMC was almost impossible. These types of accidents happen all the time. But they can be avoided.

Third, then, is to look for a solution inexpensive enough for general-aviation aircraft. And here we are fortunate. At least two companies (Blue Mountain Avionics and Dynon Avionics) make Electronic Flight Information Systems (EFIS) in the vicinity of $2,500 which are self-contained and provide an hour or more of operation on backup batteries. Using advanced but proven technology, these solid-state units have all components housed in a standard 3 1/8" round package. They connect only to the power bus and to the pitot/static plumbing, requiring no vacuum. And the wealth of information they provide is stunning, considering their small size, low power consumption and moderate cost. In the figure you can see that the unit gives attitude (both artificial horizon and bank angle), airspeed, altitude, vertical speed, compass heading and turn rate. It even provides turn coordination with lateral ball acceleration.

But there is a catch. The units are sold for experimental aircraft and are not certified. So our fourth task is to ask if there is any downside to allowing these instruments to be installed on certified aircraft solely for reference and backup purposes. When you consider the design of these units -- all solid-state, with no moving parts -- and the low power consumption (typically 8 watts, 20 watts if the internal battery is charging), it is immediately evident that inclusion of this instrument will not adversely affect an aircraft. Especially considering that the standard installation will be via a fuse or breaker.

Fifth, we need to ensure that pilots who install these "experimental" instruments on certified aircraft use them only as secondary instruments. One solution is to placard the instrument with a warning: "Reference and backup only". (If the FAA reverses its policy, manufacturers are willing to modify these units so the "reference and backup only" warning appears on all the screens, as shown in the first figure above, and to include a start-up sequence where the pilot has to accept these conditions of use before the unit will activate, as shown in the figure at right4. In this example, the start-up screen includes an indemnification and release statement to protect the manufacturer, which leads us to the point in the next paragraph.)

Sixth, getting the FAA to allow the use of these units on certified aircraft is not enough. We need to provide an environment where the units can continue to sell at these prices. We want to avoid the certification costs and liability concerns that in many instances force a manufacturer to increase the price of its units for certified aircraft by a factor of 4 to 10 times. The solution is to allow these units -- without certification, specifically labeled as "experimental" and modified only to incorporate the screen warning and start-up sequence described above -- to be installed in certified aircraft. Again, a review of the design and construction of these units, and their performance in many years of use in experimental aircraft, will show that they are reliable products which will not adversely affect aircraft and which can be approved for installation now, without certification. Retaining their "experimental" label has two advantages. First, it strengthens the "reference and backup only" condition of use. Second, it substantially relieves the liability concerns of manufacturers, with the users accepting that they, not the manufacturers, will be responsible for any damages and claims resulting from an accident.

Lastly, we want to suggest preferred and alternate approaches to convince the FAA. In the preferred approach the FAA recognizes that technology -- and common sense -- have outpaced its well-intended refusal to allow non-certified products on certified aircraft, and makes an exception in this case, permitting their installation. This approach allows the FAA to herald that it has entered the 21st century, that it is willing to change decades-old policy when technology and other factors warrant it. But if resistance within the agency threatens these goals, then there has to be another way. Perhaps a directive by the FAA identifying the units and leaving the matter to the District Offices (we assume here that the FAA inspectors will get the meaning of such a directive). Or perhaps using a scheme where the instruments plug into the cigarette lighter of aircraft, as used by sellers of traffic alert devices to circumvent the prohibition of using non-certified devices connected to the power bus of certified aircraft.

In any event, an effort must be found to achieve this life-saving objective.

In the end, the preferred solution is a single-sentence statement from the FAA identifying these units and stating "These experimental units may be installed per the manufacturers' directions in certified aircraft for reference and backup use only, via the standard Form 337 process."


1. Ernie Martin has Bachelor's and Master's of Science degrees in Engineering (the Master is from Caltech). He spent nearly 20 years in satellite communications and 10 years in the jet engine business. He has worked on FAA projects and for a time worked directly with John McLucas, former FAA administrator. He has also consulted for various companies, including GE, and currently heads ConsultResearch, Inc. Based in Miami, he frequently flies his 1973 Cessna 337G Skymaster over Caribbean waters and has flown his previous Skymaster on search-and-rescue (SAR) missions over the Florida Straits and on a trip across the United States. He may be reached at .

2. EFIS stands for Electronic Flight Information Systems. The EFIS features mentioned here are for a typical unit. Different manufacturers incorporate different features.

3. In several of the FAA Flight Standards District Offices (FSDOs), enlightened inspectors have approved such installation, often after extraordinary -- and costly -- efforts by the installing shop or a Designated Engineering Representative. In general, however, the FAA does not approve the installation of non-certified units in certified aircraft. The uncertainty of whether an FSDO will approve such installation, especially considering that it may run counter to FAA policy, effectively precludes it. Users are not going to purchase and install the equipment (including re-arranging the panel instruments) without assurances of approval.

4. Correspondence and telecon with Greg Richter, head of Blue Mountain Avionics, in January 2005.