The 36-Pound Radio

Lightweight avionics are here

March 1, 2008

Answer: Despite navigation and communication radios becoming lighter and more reliable, and auto-pilots gaining traction among small aircraft operators, some pilots refused to come into the times and give up the plotter and flight computer.

Question: What is 1958?

Oh, I’m sorry, we were looking for 2008.

It may be surprising, but the truth remains. Radios and autopilots dominated the pages of The AOPA Pilot’s first issue in March 1958, much as they do today. Niche companies offering things such as plotters and E-6B wind-triangle (flight) computers filled the ranks of the advertisers. Funny how every pilot who learns to fly today is still taught how to use a plotter and flight computer, eh?

Of all the advertisements in the magazine’s first issue that dealt with gear (loosely defined as avionics and pilot supplies), roughly two-thirds were from radio and autopilot manufacturers, many of which are still in business today. Pilots with a little more life experience will recognize names such as Tactair, Globe, Sun Air, Nova-Tech, and of course Lear. Narco (National Aeronautical Corp.), and Mitchell (better known as Century) were on the pages and still proliferate in today’s airplanes. A sampling of other advertisers includes Safe Flight, which still produces scores of products for business and commercial aviation, float-maker Edo, Puritan Compressed Gas Corporation, and Weems, a name known worldwide for navigation products and education. Because the magazine had a small staff at the beginning, virtually all mention of gear was through advertising, unlike today’s balance of editorial and advertising.

Turning the pages of the magazine reveals a clear view of aviation’s past and tells us not only who was developing what gear, but what challenges they faced while doing it. The biggest problems? Weight, size, reliability, price, and market competition. Talk to an engineer at Garmin or S-Tec about challenges they face in developing new products today and chances are they will spout that list almost verbatim.

Things have changed somewhat with the expanded use of software, but many manufacturers face the same pressures. When an advertisement or a story is published today that lists weight, reliability, or size we’re often led to believe that these are new issues facing the manufacturer.

But the struggle to reduce weight, especially, is an issue that began in North Carolina in 1903. Well, chances are it was actually the first time someone jumped off a cliff with canvas “wings” tied to his back, only to learn the importance of the weight vector the hard way.

Whistle to tune

Of all the gear in the original issue and those in the following few months, the most recognizable name to most general aviation pilots is Narco. Sun Air, Nova-Tech, Skycrafters, and the Roscoe Turner Aeronautical Corp. all purchased spots in the first issue to market their radios, but the National Aeronautical Corp. had most of the market share then, and is still widely popular today.

Established in 1945, Narco claims to be the oldest GA avionics manufacturer in the world still in business, and the company’s whistle-stop tuning was both the dominating and revolutionary technology of the time. Prior to whistle-stop tuning, a radio user would have to select a crystal-controlled transmitting frequency to transmit and then tune a separate knob to set the desired receiving frequency. But the reception frequency was difficult to tune and the pilot had to tweak the dial, much like home or car radios before they recently went digital.

With whistle-stop, the user only had to rotate the tuner until they heard a whistle, at which point they would stop. Hence the expression whistle-stop tuning. Narco’s Omnigator Mk II was the subject of the company’s first advertisement in the magazine and it featured whistle-stop tuning. It could also receive localizer, VOR, and marker beacon frequencies. That was pretty impressive capability for a radio at the time.

But the Mk II also featured some-thing new to aviation radios just a year or two prior. Crystals tuned to exact frequencies were welded into the circuit, allowing the user to further pinpoint a frequency. This was the beginning of being able to simply select a frequency and forget about it.

All that capability came at a price. The Mk II weighed 18 pounds, a middleweight for its day. Sun Air’s five-channel radio (tunable to five possible transmitting frequencies) came in at a hefty 36 pounds, while Roscoe Turner’s radio came in at only 11 pounds. For sake of comparison, Garmin’s SL40 nav/com weighs only two pounds. Speaking of price, it was all over the map. Nova-Tech’s radio was only $189, plus $10 for each additional crystal, a real bargain for the time. Depending on who’s doing the calculations, that works out to $1,350 in today’s dollars, or roughly what a new nav/com costs today. At the high end, Sun Air was charging $1,095 for its transceiver, equivalent to a whopping $7,600 today.

Of course, weight and price weren’t the only issues. Space was a major consideration, as it is today in most panels. At least in Narco’s case, panel mounting wasn’t the only problem, however. The Mk II had a remote-mounted component filled with heavy vacuum tubes. The Sun Air radio had the same problem. The panel was an issue though. Many airplanes just weren’t built with the idea of putting in huge radios. Nova-Tech’s advertisement showed their Air-O-Ear mounted below the panel, almost like a CB radio in a 1975 sedan. Others were smart enough to photograph the radio on a table with no other references for size, leaving the pilot to infer, or at least hope, it was small. To compound the problem, each radio was a different size and shape as well. Radio sizes weren’t standardized until years later. Interestingly enough, that size is 6.25 inches wide, popularly known today as a Mark Width after Narco’s Mark series of radios pioneered at this time.

Take it easy

Go relaxed! Arrive untaxed! Such was the mantra of Globe Industries. Autopilots are all about making life easier and safer for the pilot and the late 1950s saw the introduction of units that made it affordable for many GA owners to install one in their own aircraft. Up until that point, autopilots were reserved for the military and commercial airlines, and to a much smaller extent, for business aviation.

Lear’s L-2 autopilot reported to be the finest unit of the day and many pilots who flew behind one would likely agree. After Bill Lear made money off his F-5 autopilot for the military, he started to develop lighter, smaller, and cheaper units for GA, a market his advisors felt was a complete waste of time and money.

Lighter was relative of course. The L-2 came in at more than 40 pounds. But Lear’s autopilot could do it all. The company claimed it was fully three-axis with yaw damping (an option), automatic pitch trim, and even a sort of altitude pre-select. There were two areas where the L-2 really excelled, both thanks to the successful F-5. Because the F-5 was designed for fighter jets, it was fast. Very fast. As a result, the L-2 had a type of servo that allowed for more precise control. Lear’s autopilot also offered what appeared to be the only fully automatic approach coupling available at the time. What we take for granted with most autopilots today was an astounding development then.

Tactair’s autopilot was another option for pilots and owners. It was light, small, and reliable. However, it was less capable than the Lear L-2, something a lot of owners didn’t mind. In fact, many older Cessna 180s and 182s and Beechcraft Bonanzas still feature Tactair autopilots, and the company is still in business, although it no longer produces autopilots.

Owners can still even get service from Jeffery Noyes, who is based in Ohio and has been working on them since he was a kid. The Tactair T-3 was technically a two-axis unit, though it was mainly created to hold a heading, which it did quite well, according to Noyes. An interesting thing about Tactair was the way it approached the back-end design. Whereas Lear autopilots operated electrically via servos, the T-3 was based on pneumatics and ran off the airplane’s vacuum pump. One major advantage of the T-3 was weight savings. The small unit came in at less than eight pounds.

Prices of the units varied. Mitchell Industries, which was bought and sold a few times until finally producing autopilots under the Century name, advertised a three-axis unit in the first issue. Many Pipers still have an autopilot that owes its lineage to the autopilot on the pages of the March 1958 issue. Cost for three-axis control? $2,425, or roughly $17,000 in today’s dollars. A top-end S-Tec Fifty Five X will set you back by about that amount today.

Amelia should have taken it

Even though advertisements for autopilots and radios dominated the magazine in the beginning, many other companies offered gear that appealed to pilots. Weems is a name synonymous with navigation, and the company advertised in the first issue. Capt. Philip Van Horn Weems made numerous contributions to navigation, including the Weems System of Navigation and his associated training course.

Although the Weems system was based upon celestial navigation and used a sextant, it was designed to be faster than the traditional method, and was thus more practical for aviation. Many famous aviators took Weems’ course, including Charles Lindbergh and Fred Noonan, Amelia Earhart’s navigator. Weems even tried unsuccessfully to get Earhart to take the class on a number of occasions.

Despite the popularity of the Weems’ system, the captain’s most lasting invention was the Mark II plotter, which appeared in the Weems ad. Many pilots will recognize the plotter as one that can be purchased today from Jeppesen. That’s because Jeppesen purchased Weems in the late 1950s and the plotter has remained virtually unchanged since. In 1958, it cost $2 ($14 in today’s dollars) for the statute mile version. Jeppesen calls it the PN-1 and sells it for $11.49.

Safe Flight Instrument Corp. was another advertiser in the first issue that continues to prosper today. The company advertised the Speed Control, a device that measured the airplane’s proximity to the stalling angle of attack and instructed the pilot to slow down or speed up via a glareshield-mounted indicator. Although perhaps a bit crude by today’s standards, the instrument was the basis for Safe Flight’s popular and successful line of AutoPower automatic throttle technology, angle-of-attack gauges, stick shakers and other business and commercial aviation products.

The one editorial contribution to gear was at the end of the issue, a section called “What’s New.” Here the editors took one page to feature six products, resulting in something more akin to news hits than product reviews.

The section continued through the October 1978 issue in much of the same format. The section’s name changed to “New Pilot Products” and continues today as “Pilot Products.” The first issue featured some more obscure items such as a new hangar and an inspection scope for maintenance. But the editors also profiled a flight computer, classroom plotter, and a portable desk, or kneeboard. Sound familiar?

E-mail the author at ian.twombly@aopa.org.

Ian J. Twombly

Ian J. Twombly | "Flight Training" Editor

Flight Training Editor Ian J. Twombly joined AOPA in 2003 and is an instrument flight instructor.