Proficient Pilot: Avionics evolution

In the beginning, a flight instructor sat in the front seat of an open-cockpit biplane and communicated with his student in the rear using hand signals and occasionally yelling over wind and engine noise. At times he would have to throttle the engine to make himself understood.

The first intercom was the gosport speaking tube, named after the flight school in Gosport, England, where it was invented and first used (1917). The instructor spoke into a small metal funnel, and his voice carried through a rubber tube to the other cockpit. The single tube split into a pair of shorter tubes that led to both sides of the student’s helmet. The student listened to his instructor as a doctor listens with a stethoscope.

Many of us who learned to fly in the decade following World War II got to use general aviation’s first popular two-way radio. This was a Motorola low/medium-frequency receiver (complete with vacuum tubes) and a single-frequency HF transmitter. Range was limited—some believed that megaphones were more effective—and fine-tuning the “coffee grinder” receiver to the proper frequency often required the pilot to ask the tower to recite a “short count for tuning.”

There were no intercoms in those tube-and-fabric trainers, and the most common way for an instructor to communicate with his student was to shout through a rolled-up aeronautical chart. Sitting in the back seat, he also could express displeasure by swatting the back of a student’s head with said chart, a practice to which as a not-so-great student I served witness.

Avionics technology in general aviation took a leap forward in the early 1950s when Narco introduced its Superhomer. This box combined a coffee-grinder VHF receiver and a four-channel transmitter with the revolutionary omni (VOR) receiver and display.

Pilots really began to live high on the hog a few years later when Narco unveiled its Omnigator. It included 27 transmitting frequencies that were selected and installed at the discretion of the owner (depending on the frequencies he most commonly needed). The Omnigator also had whistle-stop tuning, a slick feature that assisted a pilot in tuning the receiver. Assume that a pilot was approaching an airport where the tower frequency was 118.1 megacycles. He would digitally select the proper transmitting crystal (frequency), activate the whistle-stop tuning feature, and then slowly crank the tuner until in the vicinity of the desired receiver frequency. As he neared that frequency, he would begin to hear a whistle in his headset. He would continue fine-tuning until the whistling reached a peak. He then turned off whistle-stop tuning and knew that he was tuned to the proper frequency. Whistle-stop tuning, however, soon became obsolete with the availability of 90-, 180-, 360-, and 720-channel transceivers. Then we changed from kilocycles (kc) and megacycles (mc) to kilohertz (kHz) and megahertz (MHz).

Despite the wide variety of navcom receivers from various manufacturers that saturated the market in ensuing years, they all had one thing in common: they were user-friendly and could be operated intuitively. A pilot could step from one airplane to another and not be concerned about knowing how to operate the avionics.

That began to change, however, in the early 1990s. This is when avionics manufactures began to develop and introduce integrated avionics units. These revolutionary systems combined moving-map displays, GPS and VOR navigation systems, sophisticated database access, and VHF communications in one box.

Although such systems were and are incredibly capable, they are neither intuitive nor user-friendly. In many cases, getting checked out in a new airplane can require spending more time learning to use the avionics than learning to fly the airplane. Add primary flight displays (PFDs) and multifunction displays (MFDs) to the mix, and you can appreciate why training in such airplanes emphasizes learning to use the electronics systems and deemphasizes the actual flying of the airplane.

Consider a pilot that is already checked out and current in a make and model of airplane equipped with steam gauges. At many flight schools he may not rent the identical airplane if equipped with a Garmin G1000 integrated flight deck without first undergoing significant additional training. Learning to use the avionics takes more time and study than getting checked out in the airplane in the first place.

Integrated flight displays and automated flight control systems obviously increase situational awareness and in-flight safety. Obtaining the proficiency and adapting to what can seem like an overwhelming amount of flight information, however, needs to be accomplished without sacrificing the airmanship needed to operate the airplane skillfully—a challenge that we need to spend more time addressing.

Web: www.barryschiff.com

Barry Schiff has held five world aviation records and four national records.