Glass Avionics retrofitted into Aircraft


We all know what to do when we experience and engine failure. Aviate, Navigate and Communicate. But, when your avionics fail and you cannot navigate or communicate, what do you do?

I have a Centurion P 210 which I upgraded with an all glass cockpit. Of course, the wet compass, altimeter, vertical speed indicator as well as attitude indicator are still there. However, the only communications and navigation capabilities are in the glass section.

Recently, I experienced a problem where the battery, on start up, indicated green; however, none of the avionics would turn on. As well, the engine would not start.

The relay behind the battery was fried and no power could get to the starter or avionics.

After replacing the relay, the plane would still not perform. Then, we checked the battery. Although it held a charge, its polarity was off. As such, it had to be replaced. Now with the new battery, life is good again, or is it?

Just think about this problem popping up while in IMC! You would have no way of communicating or navigating (except for using a wet compass). In essence, you are DEAD.

While new aircraft with glass panels are equipped with a backup battery system, retrofits are not.

MY RECOMMENDATION - never fly without a fully charged portable transponder, preferably with VOR capability. There is the only alternative unless you want to become a statistic when your landing is into a mountain, tower or body of water.

I remember when, in 1986, the old time pilots with their cubs and the like felt imposed upon having to have radio communications. As well, I also remembered the screams from the same when Mode C was required.

This, however, is absolutely fatal unless you have some manner to communicate and, hopefully, navigate. To test the battery prior to takeoff only assures you that you might get into the air before all is lost.

Jim Downey N532CH


Good point Jim. Relays don’t normally just give up mid flight, but they can. Most light aircraft don’t have the space or excess weight capacity to carry a second battery dedicated to getting you on the ground. The main battery is supposed to give you 30 minutes but if you should have bought a new battery last month or fail to turn off all non-essential electrical goodies on or the wrong relay fails you are in deep trouble. I’m not sure a transponder would be on my “to carry” list but a good handheld with even a basic VOR indication and/or a portable GPS would be worth it’s weight in gold at that point.

John in Saudi