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THE MARCH OF AVIONICS TECHNOLOGY

THE MARCH OF AVIONICS TECHNOLOGY

Article appeared in Flying Magazine March 2020 by John King

My instructor was in the backseat behind me.  He was always yelling at me.  This time he was yelling that I needed more rudder when I used aileron.  I was a teenager.  I thought he was mad at me.  I know now he was just trying to be heard over the ambient airplane noise.  The airplane was an Aeronca 7AC Champion.  It had no electrical system or intercom system, and we had no headsets.

I didn’t think of the airplane as missing anything.  The other airplanes on the field were similar.  I just thought that was the way airplanes were made.  I had no idea of the march of avionics technology I was to witness in my flying future.

Of course, we also had no electronic navigation.  We used pilotage, comparing the chart to landmarks; and dead reckoning, holding a heading and speed and keeping track of time.  In ground school we learned to draw our proposed ground track on a chart.  We drew another line to the destination representing wind direction and speed.  We used the lines to plan our heading and time for the trip.

Pilotage, comparing the chart to landmarks; and dead reckoning in combination with this panel was how things were done back in the day.

In the early 50s, things became more complicated when the FAA mandated that pilots demonstrate emergency instrument skills for a private pilot certificate.  This required airplanes with electrical systems for the turn indicator, and vacuum systems for the attitude indicator and heading indicator.

I didn’t participate personally in this particular technological advance.  The airplanes with instruments cost more to fly.  I was saving up to go to college.  The $8 per hour that I was paying for airplane and instructor was all I felt I could afford.  After I soloed the Aeronca on my 16th birthday I decided to stop this outrageous expenditure, and quit flying.

The cockpit of the new King Schools Cessna 172 with Garmin G-1000 avionics. This airplane is featured in King Schools courses and videos and is often flown by King Schools employee pilots.

Years later, I resumed my flying in companionship with Martha.  We bought a Cherokee 140.  It, of course, had an electrical system.  It was also decked out with dual nav-com radios.  I was introduced to radio communications and navigation.  It was a big step up from my days of pilotage and dead reckoning.

When we got our Private Pilot certificates, we got the lust for something faster.  We bought a Piper Comanche and set out explore the rest of North America.  On our way to Barrow on the North Slope of Alaska we discovered in Fairbanks that we needed more than VOR navigation.  We needed ADF to navigate our way any further north.  By now I apparently had lost my pre-college frugality.  Martha and I laid out the money on the spot to have an ADF installed in our Comanche.  ADF had been around a long time and was not really an advance in technology.  But to us ADF was new technology that allowed us to go further north.

As we continued to fly the Comanche, we flew more and more IFR.  Since we were equally hooked on flying, we had no financially responsible partner when it came to spending for avionics.  When Martha and I wanted DME to support our IFR flying, we immediately laid out the funds to put a DME in our Comanche.

When the technology became available in 1978, we sprang to install a King KNS 80 in the Cessna 340 we owned by then.  The KNS 80 was referred to as a course line computer.  It would electronically move a VORTAC to a new location.  Using the signal from a VORTAC within reception, we could navigate to or from the computed position miles away as if the VORTAC were actually in the new position.  It was our first experience at being able to navigate by VHF in a straight line as far as 199 miles, without having to go from navaid to navaid.  The capability was referred to as area navigation.  The KNS 80 could store four preset waypoints so you could quickly switch from one waypoint to the next.

In 1990, Narco Avionics came out with a product for general aviation called StarNav.  It took navigation to the next level.  StarNav was a multisensor navigation system containing VOR, localizer, and glideslope receivers.  It had a database allowing it to automatically tune nearby navaids to provide a continuous navigation solution.  We installed StarNav in the old Citation that we had then.  As friends of Ed Zimmer, the owner of Narco Avionics, we were beta testers.  It was Martha who suggested the name “StarNav.”

In addition to utilizing its self-contained sensors, StarNav interfaced with other receivers including DME and loran.  Loran referred to long range navigation.  It was originally developed for marine navigation.  Loran allowed continued navigation even when we were out of range of VHF signals.   Eventually we replaced the loran in our Citation with GPS, which gave us improved position accuracy.  StarNav was our first experience with the combination of a database and area navigation for nation-wide automatic navigation.  Today, GPS systems combine that capability with a map to routinely provide simple, intuitive navigation.

In its early days GPS wasn’t as useful as it could be because the military dithered the signal for civilian users. This dithering deliberately added 50 meters of error horizontally and 100 meters vertically to GPS signals.  This was referred to as “selective availability.”  In May of 2000 selective availability was removed, making GPS vastly more precise and practical for civilian use.

On July 10, 2003, the Wide Area Augmentation System (WAAS) was activated for general aviation, covering 95% of the United States, and portions of Alaska.  This even further improved the precision of GPS.  WAAS works by having ground stations with known positions receive the GPS signal.  They then correct any errors and send the correction for the area back to satellites, which then send out the corrected signal.  WAAS allows a position fix within 10 feet, 95% of the time.

A WAAS receiver is required for ADS-B Out.  With ADS-B every airplane reports its very precise position to all the other aircraft in the vicinity, and to ground stations.  With WAAS we can now see the accurate location of every nearby airplane on our screen.  This has already proven to greatly reduce the collision rate and save lives.

It is hard to imagine how far avionics has come.  Navigation and situational awareness in the cockpit is vastly more precise and easier, and information is incredibly plentiful.  Plus, it’s all a lot more fun.  Our GTN 725 displays our position, weather and traffic information on the same screen.  It is wirelessly connected to our iPads which serve as additional multi-function displays, providing the information available from the panel navigator and displaying it very intuitively.  At home our pre-flight preparation supplies us with more copious current information with more immediacy and better detail than was available even to flight service station operators in our early days of flying.

It has been a great journey.  Even though I am no longer a sixteen-year old kid, I still have no idea what the future holds.  But with the accidental wisdom of experience, I can tell you that change will continue in increments, and that in a few decades we will have arrived in a marvelous new place.  I am looking forward to it.

8 Comments

  1. Paul Everitt

    Another great heart-felt article, thank you John!
    I learned to fly in a Cherokee 140 in 1975, loved that aircraft, esp. the overhead trim handle!
    Got my FAA Comm in 1976 and have held it current ever since.
    As you say it’s sure been an interesting ride, seeing how technology has totally transformed the way we fly.
    And yet jumping back into a no-electric no-radio 1940’s Cub on old straight Edo floats and hopping around a few lakes for the day, is still a huge blast of pure uncomplicated flying FUN!
    Watching King Schools grow and evolve through the years under your & Martha’s leadership, has been another joy to behold in General Aviation.
    Wishing you & Martha all the best, we all love you both, cheers!

  2. Sven

    Thank you for that article.
    I learned about flying from King CD-ROMs on Windows 98 before climbing into C172 cockpits – it was a lot of fun, and I admired back then already how you guys keep embracing and share your enthusiasm about new technologies!

  3. Richard Bailey

    In my many years of flying, often with students, I have experienced many alternator failures, a belt failure, a couple of voltage regulator becoming a voltage roadblock, and a short-circuited battery; all of which resulted in loss of electrical power. This and checkride demands are why I insist on a very thorough understanding of pilotage and dead reckoning.

    ForeFlight, in addition to being truly wonderful in multiple ways, is a great comfort when one of the above happens. One bright moonlit night I had alternator failure. With my handheld radio I advised center that I was shutting everything down to save power for the landing light at destination. I knew the route well but really felt safe with my brand new IPad and ForeFlight. Center noticed I was tracking a straight line and asked how without navigation. I told them Foreflight. It was so new they had never heard of Foreflight or an IPad.

  4. George Moomaw

    I enjoyed the trip down memory lane. After my father came home from WW II he learned to fly in an Aeronca Champ. My first experience flying was in that plane at age 5. For the next 60 years, while raising 4 kids, all I did was dream of flying.

    I earned my certificate at the age of 65 with King Private Pilot Course. (I’m a late bloomer). The video’s and materials were GREAT. My wife (Martha) enjoyed watching the videos too, but never cared about earning a certificate.

    Now at 73 I have to renew my medical to start actively flying again. Your reminiscing here reminded me of just how fast time goes by. I need to get going before I am no longer physically able to do it.

  5. Mike Stone

    John, I can appreciate your story. I began flying in 1946 Taylorcraft with no electrical system, I had a sectional and an E6-B, and I had no problems. Now it feels like cheating when I make a cross-country in my A36 Bonanza with a 750 GTN, ADS-B, Sirius X-M weather and radio, Strikefinder, and an iPad with Foreflight. It’s faster and easier, but I’m not sure it’s near as much fun as propping that Taylorcraft and flying at 1,500′ across Texas. Thanks for the reminder of those times. Mike (King student for 30 years, still have those VHS tapes but no player!)

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