Non-Competing Operating Procedures For Avionics

by Michael Kaufman

If anyone had a new aviation product to introduce to the public, the two places to do it would be at EAA AirVenture in Oshkosh, Wisconsin, or Sun-n-Fun in Lakeland, Florida, depending on the time of year. I browsed the display areas at Oshkosh this year to find some interesting items to write about that dealt with avionics and instrument flying. I had previously written about a product that would bring FREE nextrad Wx to the cockpit. This was the Stratus system that worked with the Foreflight i-Pad application and available from Sporty’s Pilot Shop. Three other ADSB Wx boxes showed up at Oshkosh as well with some added features like adding ADSB traffic to the display. I hope to evaluate each of these units and discuss them in future columns.

I have been waiting anxiously to fly the new Avidyne IFD540 GPS unit that will be shipping the fourth quarter of this year (2012). At Oshkosh, there was an announcement that Avidyne will be producing a slide-in replacement for the Garmin 430 GPS – the IFD440 to complement the IFD 540 – which is a slide-in replacement for the Garmin 530. I am very anxious to get the opportunity to review these new GPS units while airborne.

As I continue to be active in flight training, I continue to see interfacing problems between GPS units, primary flight displays (PFDs) and autopilots. Some of these problems have existed since installation or a revised software or firmware update. The pilot/aircraft owner gets these words from his avionics shop: “This is the way it is supposed to work.” As most avionics technicians are non-pilots and the pilots are not avionics experts, this problem may exist for years before another pilot or technician sees and corrects it. Many avionics technicians are frightened to ride in an airplane with a pilot they do not know to diagnose an avionics problem in flight (and rightfully so), and in some cases, this is the only way to duplicate the problem situation. A bit of advice I will give to every pilot… “Do not take off in a strange airplane or one that has just come out of maintenance to fly in a demanding IFR situation.”

When I get into an airplane I have not flown before, I need to see how all of the avionics work together. In the early days of GPS, each FAA Flight Standards District Office (FSDO) set the standards of installation in their jurisdiction.

All GPS units installed by Wisconsin avionics shops that shared the CDI needle with the VOR/ILS indicator needed to auto-switch to ILS whenever the VOR/ILS radio had an ILS frequency selected by the pilot. I was inbound to Madison, Wisconsin (KMSN) flying a Mooney in instrument conditions and navigating with a King KL90B GPS and switched to the Madison ILS frequency on the Nav/Com. All seemed to work okay – the glideslope and localizer came alive and I turned inbound on the ILS. Madison Approach gave me a call that I was not established and I was confused; the needles showed me established. The conclusion to this error was that the glideslope needle was coming from the ILS frequency on the NAV/COM radio, but what I thought was the localizer course needle was actually the indication coming from the GPS which did not switch automatically. I learned that all GPS installations had not been mandated by the FAA to be done the same way.

Today, I still see many strange installations. For example, two GPS steering modules receiving GPS data and supplying data to the autopilot, one from the built-in module on an Aspen PFD, and the other from a previously installed Icarus (SAM Module). This can be confusing. The VOR/LOC indicator in my Bonanza is an electronic display, rather than mechanical needle. It has a reverse button to be used when flying a back course approach. If I also hit the reverse button on the autopilot when using this function on the localizer indicator, it will reverse the reverse and that does not work well when flying the back course.

I would like to give an example of a Garmin firmware update that has been around for some time, and most Garmin 430/530 boxes have it by now, before continuing on with some tips on flying and programming these boxes that I have done in previous columns. With the advent and popularity of GPSS, it became apparent that pilots elected to fly the digital GPS signal generated by the GPS on their autopilots, rather than the analogue signals from the proper source. This was especially true on localizer-only approaches, as those GPSS modules did such a superb job of tracking the GPS course. The intent of a localizer approach was to have the pilot follow the localizer signal when flying the localizer approach and a legality issue developed. Garmin (via firmware update) now disables the output of digital GPS signals to the autopilot at the final approach fix to keep pilots from using the GPSS module on the approach. If you are using the Icarus (SAM module), the digital input light will flash and the voice will indicate, “GPSS disengaged.” Once you know how your equipment interfaces, and there’s no new firmware update, it is safe to fly serious IFR in that airplane.

Every pilot has ideas on how he/she would like their Garmin 430/530 boxes set up, and there is no right or wrong way.  I have found these hints quite useful if you are fortunate enough to have a Garmin 430/530 stack or one of the Garmin portables (396/496 or 696).

Many times we have heard, “Cessna 2852F, we have an amendment to your routing. Advise when ready to copy.”

You have your previously assigned route in your primary navigator, the Garmin 530 (for example), and had auto cross-fill enabled on the 530, so your routing is also in the Garmin 430. You go to the flight plan page on the 430 and amend the flight plan – or if considerably different – build a whole new one. Here it is advisable not to have auto cross-fill enabled in the 430 as you can then update the route and check it prior to sending it to the 530 and autopilot using manual cross-fill. Another point to consider when using the cross-fill function requires that both GPS databases must be of the same revision to work.

If you would like to see your route from your primary in-panel GPS displayed on your portable GPS, that can also be done, but not by the cross-fill method. Your avionics shop can make a bridle cable to allow the flight plan to transfer to your portable unit. Whatever is in the panel mount GPS unit, will be auto transferred to the portable, (including waypoints that are not in the portable GPS database). Sometimes it may be desirable to build a flight plan in the portable unit to see how the route will take you around some weather that you have displayed on the portable GPS unit. This cannot be done with the bridal cable connected, so have your avionics shop install a simple toggle switch to break the transfer stream of data from the panel mount unit.

I will continue to share some of my operations and IFR flying techniques in future columns, and I would appreciate you sharing with me some of yours, as this makes us all safer pilots. You can e-mail me at or call 817-988-0174.

Fly safe, fly often, and stay current and proficient!

EDITOR’S NOTE: Michael “Mick” Kaufman is the manager for the Beechcraft Pilot Proficiency Program and a flight instructor operating out of Lone Rock (LNR) and Eagle River (EGV), Wisconsin. Kaufman was named “FAA’s Safety Team Representative of the Year for Wisconsin” in 2008. Email questions to

This entry was posted in Columns, Columns, Instrument Flight, October/November 2012 and tagged , , , , , , , , , , , , , , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published.