Cirrus

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Written by Duane Wilson
Pushing the Pattern airplane envelope
As seen in the September 2021 issue of Model Aviation.
1962 world champion tom brett displays his original wing
1962 World Champion Tom Brett displays his (original wing) state-of-theart Cirrus and firstedition Quadruplex proportional radio before its initial flight. The colored ribbon designated the frequency and was also a handy wind direction guide.


It’s the summer of 1962, and after a dramatic flyoff with Britain’s Harry Brooks, you’ve been declared the second FAI World Champion, with the first having been the US’s Ed Kazmirski two years earlier ("Kaz," Model Aviation, August 2010). You are on top of the RC Aerobatics (Pattern) world. Your sleek, winning Perigee design (now in AMA’s National Model Aviation Museum), will be kitted by a top manufacturer, and the construction article that was written for American Modeler magazine will soon be out. As the days and weeks pass, euphoria and satisfaction lead to wondering, "Where do I go from here?"

Those of us who fly RC should have some knowledge of RC history—knowing how we got from where we were to where we are now. Let’s go back and explore a brief period of early RC Pattern history. We’ll need to mentally put the present and all of its technological advances aside, then use our combined imaginations to transport ourselves to early 1963, a year before the Beatles came to the US.

In 1963, many important advances in RC were just around the corner. These were the pioneering days of RC Pattern, and a promising, but undetermined, future lay ahead.

the cirrus lifts off for the first time in 57 years
The Cirrus lifts off for the first time in 57 years.


In the late 1950s, RC flying became more attainable with the development of the reed radio. There were toggle switches for each control surface, and servo operation was all or nothing. Before reeds, simply keeping airplanes aloft and flying in a semi-controlled way for a short period was considered successful flying. Early escapements and the Galloping Ghost (picture continuously fluttering control surfaces at full travel) radios didn’t prove to be attractive or reliable ways to fly.

Although reeds made controlled flight possible for a wider modeling public, operating the toggle switches felt neither natural nor intuitive. Flying multichannel reeds was a learned skill and challenging. Newcomers tried to keep their trainers in the air, while more experienced fliers tended to jerk their airplanes off the ground and around the sky. Only the most skilled could fly aerobatics smoothly with reeds. Tom Brett, the 1962 World Champion, proved to be the best that year.

There was rapid RC growth during the early 1960s, with the fledgling modeling industry following closely behind with an explosion of better radios, engines, and a variety of modeling accessories. Reed radios would rule the radio market until the mid-’60s, but a new era of flying was close at hand as the proportional radio, which had been the standard for more than 50 years, was about to come of age. The transition from reeds to proportional radios is central to this story.

As part of the US team in 1962, Don Brown competed with an improved, refined version of the Galloping Ghost—a fully proportional control system of his own design that he called Quadruplex. At one point, he led the competition before experiencing engine trouble, but his skill with the new radio was impressive enough for him to finish fifth overall despite that setback.

Although a dedicated reed flier, Tom was intrigued by the new radio and recognized that proportional could become the future of RC. Collaborating with Don, he decided that his next and most ambitious Pattern aircraft would be flown with Don’s proportional radio.

team brett member ed gonzalez gives the thumbs-up while fitting the new retracts
Team Brett member Ed Gonzalez gives the thumbs-up while fitting the new retracts. The wing had not yet been repainted.


Incorporating an extra "wow factor" into the design, Tom added something unheard of in Pattern models at that time—retractable landing gear that was introduced by fellow Pattern pioneer and manufacturer, Hal deBolt.

As World Champion, international interest was focused upon Tom’s upcoming 1963 project named Cirrus (after the fast-moving, wispy, upper-level cloud). The Cirrus would showcase the new technology for Pattern aircraft of the future and would prove to be several years ahead of its time. It was one of the first Pattern airplanes (if not the first) to use both proportional radio and retracts. (The tuned pipe would come later).

Whether or not he realized it at the time, Tom hit upon a successful formula that would set the standard for the next 25 years.

jerry black spa expert and test pilot extraordinaire
Jerry Black, SPA expert and "test pilot extraordinaire," poses with the Cirrus before the first test-flight.


In hindsight, we knew that proportional would largely replace reeds by 1965, with 74% of the top US competitors using them at that year’s Nats. Retracts also became customary at the highest levels of competition by the early 1970s, but in 1963, both were novelties and unproven technologies.

Tom lavished his engineering skills and time into designing and building the Cirrus. He paid careful attention to the smallest details, even engineering working doors for the retracts. Because of their bulk and weight, equipment placement was critical when planning the design.

The metal-encased radio components and retracts were huge and heavy compared with modern ones. Despite carefully selecting the airplane’s balsa, and the airframe itself weighing only 3 pounds, 2.6 ounces, the radio equipment (and particularly the retracts and required batteries) pushed the overall weight of the Cirrus to nearly 8 pounds—a formidable weight at the time.

With our current choices for glow and electric power, it’s hard to imagine the relatively anemic power choices that were available in early 1963. Breakthroughs in engine quality and power were on the horizon, with much stronger .61 two-stroke RC engines becoming the recognized standard within 3 years—but again, not in early 1963.

Tom determined that the best RC engine that was available was the .49 Merco made in Great Britain, but good performance in a heavy model was a lot to ask of any .49 engine. Predictably, vertical performance during aerobatics would be limited, but performance wasn’t the primary objective. The Cirrus was first and foremost a test platform.

When it was completed in March of that year, Tom’s sleek Cirrus was arguably the "coolest," most advanced Pattern model in existence. A superb builder, Tom’s blue-on-blue paint scheme, with stylish gold silk covering the wing’s open areas, created a strikingly handsome aircraft.

The visual impact of watching those wheels lift for the first time can’t be overemphasized; it was revolutionary. The wheels just looked better up, and smooth performance was the benefit.

helen brett proudly displays her scrapbook of toms rc career achievements
Helen Brett proudly displays her scrapbook of Tom’s RC career achievements.


Flying the Cirrus

The Cirrus made its maiden flight in the early spring of 1963. According to Helen, Tom’s wife who is still his biggest fan, "He did the preflight check and taxied around quite a bit, getting the feel of the controls. It moved out well on takeoff and lifted nicely. Tom was never one to rush a plane into the air. [He] liked a lot of ground speed."

Unfortunately, Tom’s early enthusiasm was short-lived because flying the Cirrus was plagued with problems and disappointments. Early on, he experienced intermittent radio problems, usually during critical times at low altitudes. After just a few flights, the Cirrus crashed on final approach, splitting the fuselage in half.

Although the Quadruplex system was touted in its ads as being the most reliable radio available, Tom’s prototype seemed to be jinxed. Throughout 1963 and 1964, the radio was returned three times and the transmitter was replaced at least once.

After that first major crash, Tom received the following apologetic letter from Don:

"Dear Tom:

"I’ve returned your system in good working order. You are absolutely correct about the transmitter not functioning properly. It had developed a problem in its blocking oscillator circuit. This is the first time I’ve seen this condition exist. The most expedient solution was to set it aside and send you a new transmitter. The outfit you have now has been thoroughly checked out and I’m sure will exhibit no peculiarities … Of all the outfits I wanted to work properly yours had to act up. Well, I guess the radio god got to it. Perhaps I’ll make a sacrificial offering to him by burning that transmitter."

After repairs, the Cirrus was back in the air. These are Helen’s brief comments: "After repairs to the broken [fuselage], he had some good flights, 5 to 10 minutes or more just getting used to the system. He made nice takeoffs and smooth landings, nothing fancy, had several short flights, no maneuvers or tricks, and safe landings."

During the build, Tom cut two sets of parts. After the crash and repair, he built the second fuselage, this time designing a larger 850 sq. in. wing (the original was 700). The new wing sported a new, lower AMA number that he received when he won the FAI world championship trophy.

The 850 sq. in. wing was huge for the time with a 74-inch wingspan. No specific explanation was given for the larger wing, but I can speculate that Tom wanted a lower wing loading and more lift for a nearly 8-pound airplane that flew on a .49 engine.

The completely new second airplane was ready by late in the season. It would be nice to say that the troubles were over, but the new airplane lasted only two days.

Helen said, "On day one, (he) did the preflight check, taxied around a bit, and made a short flight. On day two, he took off and flew a bit but made a cartwheel landing, totaling the second plane. We never discussed (the) cause of the crash, but we thought it was due to another equipment malfunction. We drove all the way home in complete silence. In October, after the crash of the new airplane, he flew the original again, did a series of rolls for the first time, still getting used to the response of the system. He never voiced concerns about handling or power."

That winter, Tom built a second 850 sq. in. wing for the upcoming 1964 Weak Signals Toledo Show that was held in late winter, proving that the new, larger wing was indeed an improvement, while reusing the original, repaired fuselage from the previous season. At Toledo, the deBolt retractable gear remained a real crowd-pleaser. It was still a novelty for most people, attracting lots of interest from the Toledo attendees and appearing in the national Radio Control News newsletter.

After Toledo ’64, the Cirrus was flown in a more aggressive way to test its capabilities. Asked about how well the aircraft performed maneuvers, Helen replied, "He did some loops, slow rolls, and Cuban 8s. I couldn’t judge if it was underperforming, and he didn’t say anything about being disappointed in the performance."

The Cirrus flew uneventfully for the rest of the 1964 season to see what it could do, but by late in the flying year, Tom’s interest was focused on his next project. He was already making pencil sketches of the futuristic, swept-wing TBX-1 that would compete in the 1965 Nats and win an award for best design ("Tom Brett’s TBX," Model Aviation, November 2016).

"He never regretted the time spent on the project. [He] found out he didn’t care for that system."

For Tom, the Cirrus proved to be a one-time experiment in early proportional radios. Already an expert with reeds, he was simply happier flying his trusty reed radio.

the cirrus was unveiled next to the first quadruplex
The Cirrus was unveiled next to the first Quadruplex, one of the first available proportional radios.


The Rest of the Story

Although it didn’t prove to be famous in terms of winning contests, the Cirrus was a significant step on the road to what Pattern would eventually become. At the end of the 1964 season, the Cirrus was retired.

Having already been a world champion, Tom’s interests evolved from top-level competition to innovative design projects such as the TBX. He and Helen would leave RC in 1966, moving on to fly full-scale airplanes together. Although proud of his achievements, all of Tom’s RC goals had been met. The models were carefully stored and remained untouched for decades.

In 2009, circumstances led me to meet Helen. I had been an admirer of her late husband, Tom, since I was a young teen, but they never knew me. With renewed interest, I studied Tom’s RC career and admired his models. When Helen downsized after Tom’s death in 1974, I was honored to be given four of Tom’s well-preserved airplanes. Two were well-known, historical aircraft and two were not. One of the latter was the Cirrus. Eventually I discovered Cirrus’s place in history, and being intrigued with its large size, I chose to refurbish and fly it with Helen’s blessing.

The Restoration

Only two of the original deBolt gear remained—the third was torn off in 1964. My first thought was to replace the ancient retracts with fixed gear and go flying, but then I remembered the 1985 movie Back to the Future. In the movie, the DeLorean time machine travels 30 years into the future, returning as a flying car that runs on nuclear fusion! I reasoned, why change Tom’s original concept? Why not give the Cirrus the Back to the Future DeLorean treatment?

In this case, the Cirrus required state-of-the-art retracts, a modern radio, and a similar size, but more powerful, O.S. 55AX engine. My primary goal was to determine how much better the Cirrus would perform, and how much weight could be saved just by making those equipment upgrades. Those changes alone would help the Cirrus fly better, more reliably, and with reduced weight.

Updating the original vintage retracts with modern ones proved easier said than done. The retract designs were radically different. Everything had to be reworked, particularly the nose wheel. Helen had told me earlier that the Cirrus was engineered around the radio and landing gear. This became immediately obvious when I took a good look at the original nose wheel. It was shoehorned into the structure, buried deep within the nose, and it used a different mounting method.

I needed help from Ed Gonzalez, a friend with retract experience. We put our heads together to solve the nose wheel retract problem. Just figuring out how to remove it required some study.

Ed was unfamiliar with Tom and his designs, but quickly turned from a neutral consultant to a committed team member. It was interesting to watch him as he developed a greater appreciation for Tom’s exquisite workmanship. Each alteration we made challenged us to work as though Tom was there supervising. Finally, the new nose wheel was adapted to Tom’s existing pull-pull setup, and it worked well.

the cirrus lifts its nose wheel as it rotates on takeoff in an early flight
The Cirrus lifts its nose wheel as it rotates on takeoff in an early flight.


I decided to reuse as much as possible of Tom’s original homemade hardware and pushrods. The rest of the upgrade was relatively straightforward because I closely adhered to Tom’s original installation but with smaller, more efficient replacements.

Tom had repaired the bottom of the Cirrus’ wing but hadn’t repainted it. The original dark blue dope was custom matched with Klass Kote and repainted, and a coat of clear protected the rest of the original finish.

The new and improved Cirrus, equipped with modern "goodies" from 50 years in the future, is a version of the Cirrus that Tom could only have dreamed of flying in 1963. Now his "dream machine" weighed only 7 pounds, 1 ounce—a full 13 ounces less, despite having to add 1.5 ounces of lead in the tail to balance the aircraft.

The Second "First Flight"

The 1963 Cirrus vision was hampered by the comparatively primitive technology that was available then. Now, after many decades of waiting, the "Back to the Future Cirrus" was ready to be tested. I asked the best Senior Pattern Association pilot that I know, Jerry Black, to make the first flight while I manned the camera.

Although the Cirrus appeared sound, when flying any 58-year-old aircraft, we could never be 100% certain. Jerry calmly taxied out to the runway for the Cirrus to again spread its wing. After liftoff, it proved to be everything we had hoped for. The reduced weight, plus a stronger engine, were a huge improvement over Tom’s 1963 version.

This is a vintage aircraft with design elements and flying characteristics that were common to the pioneering Pattern era. The early, semisymmetrical airfoil and raked-back rudder line would eventually be phased out by future designers to improve performance.

Jerry reported that the Cirrus flew gently and predictably. With a nearly 2-meter wingspan, it looks graceful and elegant. Although an ancestor of what would become the "ballistic" Pattern airplane, the Cirrus moves at a peppy but unhurried pace through the maneuvers. It can easily handle basic vertical maneuvers, such as loops at 3/4 throttle, and seems happiest at that level. Because of its overall flight characteristics, the Cirrus would make a great sport model today.

There is a certain feeling you get from flying a classic Pattern airplane, especially one sporting a built-up wing with open areas that show the structure. Tom’s distinctive golden silk areas glow as the Cirrus passes overhead. Just as when it first flew, there is a huge difference in the "cool factor" when those wheels are tucked up. The Cirrus takes on a decidedly different, more streamlined look, and performs noticeably better that way. You might want to build one yourself to own a little bit of history.

My heartfelt thanks to Helen for her time and patience in answering my questions. I couldn’t have written this without her remembrances and pictures from her extensive scrapbook of Tom’s RC career. Helen truly embodies the ideal of an enthusiastic RC wife.

SOURCES:

Model Aviation archives

http://library.modelaviation.com/ma

 

The Cirrus makes a slow, banking "beauty pass." The large, 74-inch wingspan looks impressive for a vintage Pattern design.
The Cirrus makes a slow, banking "beauty pass." The large, 74-inch wingspan looks impressive for a vintage Pattern design.
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