By Cresswell Walker
This article first appeared in RAA’s Recreation Flyer in March, 1993.
A change in personal fortunes resulted in a two-year commitment to work in the Canadian North. My pregnant wife and I were to spend a year in Rankin Inlet on the north shore of Hudson’s Bay and a year in Yellowknife in the Northwest Territories.
The very long, dark, cold winter months of the North are everything the rest of the world imagines them to be. And so, after the 33rd consecutive weekend in our apartment listening to the howling winter winds of Rankin Inlet, it was clear to me, that I needed a “project” and what better project than an airplane to wick up all my spare time (and cash!)?
Now, I was (and still am) a novice pilot. At the time I had about 60 hours of glider time and about 55 hours of power time. Clearly it had to be easy to fly. Also, I had about 0 hours of “airplane building time”, so it had to be easy to build. I didn’t have a shop to build in, so it had to be small enough to build in an apartment, and lastly, I didn’t have any money so it had to be cheap. Pretty tall order. I hadn’t gotten very far with this plan when I met in Rankin Inlet a fellow exile from Vancouver, who, without either wife or child, was even more desperate for a project than I. Considerably more experienced as both pilot and builder, he was just finishing up the “tail feathers” of a MiniMax. The rest of it was still in shipping crates in his living room, kitchen, bathroom and second bedroom. I could see this was a project to live with! He made a set of plans available to me and I was off.
On the ground, the MiniMax looks like an adult sized model airplane. Low wings and a traditional tail, give it a “real airplane” look uncommon amongst single seat ultralights. There is no rocket science here, the MiniMax is a “wood and fabric” aircraft, designed around long established wood engineering construction practices, modified for the use of modern epoxies, aircraft plywood and new covering systems. Except perhaps for the Rotax two cycle power plant, this is a low tech airplane. With the canopy on, it resembles some of the control line contest planes some of you may have flown as kids, but it flies much better than my models ever did!
This is a real airplane, capable of climb rates in excess of 1200 feet per minute (w/Rotax 447) and a comfortable cruise of 50 to 60 MPH. Conventional three axis controls to large control surfaces make it very comfortable. Full span ‘flaperons’ on “shoulder” mounted wings make for amazing roll rates, and it’s relatively short fuselage makes for very responsive pitch and yaw control. Most significantly, pilot positioning very close to the center of gravity makes the MiniMax an aircraft you ‘wear’ rather than ‘sit’ in. It is the most fun thing to fly this short time pilot has ever had the pleasure to get into. But more later.
The design of the MiniMax is simplicity itself. New wood construction techniques, using modern epoxy resins and epoxy fillers are combined with traditional wood engineering. Sitka spruce, specialized aircraft plywood and epoxy are easily fashioned into structural members that are strong and precise. For those with an affinity for working with wood, the MiniMax offers many hours of good ‘plane’ building enjoyment. All fittings are hand made by the builder from aircraft alloys and all fasteners, cables, etc. are aircraft quality.
The plans reflect this dedication to simplicity. Except for a full size rib pattern, the complete plans are contained in twenty-three 17″x11″ sheets stapled in a booklet. The plans are very clear, easy to “read” and un-cluttered with instructions. It’s all there, but it’s up to you to decide what to build when.
The wings are square, with constant cord sections to facilitate construction. Twelve identical truss ribs per side are made of º” square spruce stringers sandwiched between 1/16″ ply gussets. The ribs slide over leading and trailing web spars terminating with spar pins at the root and simple cover plates at the tip. Compression and diagonal bracing gives transverse rigidity. Leading edge 1/8″ nose ribs are 1/16″ ply covered and the trailing edge is trimmed off and re-attached with hinges to give full span ailerons/flaps. The fuselage is a simple tapered box girder of spruce stringers and plywood facing and gussets. I added a turtle deck for my own enclosure design and to clean up flow over the fin and stabilizer. Finally the whole business is covered with heat shrink aircraft fabric and painted. Once materials are dimensioned, as supplied in kit form, it can be constructed with a good hack saw and with some simple hand tools
Landing gear is rigid type with solid one piece axle. Wing struts from both leading and trailing spars attach to the axle protrusions beyond each wheel. With a pull of two pins and an axle bolt, and quick release of the aileron cables, the main wings are off.
The uncovered structure, especially the wings, are things of beauty. You’ll need an arm chair to sit in to enjoy the fruits of your labours, or perhaps like us, you’ll want to hang a wing on your living room wall as a conversation piece and shelf to place greeting cards and knick-knacks on. It is as much fun to build as fly. This “man sized” model is a home-builders dream.
Before I could get started on my “project”, Christmas intervened and so a holiday to the South (Toronto, that is) was arranged. A move to Yellowknife was also to occur over the festive season, so we left Rankin Inlet behind for the last time. Foolishly, I thought it would be possible to cut some cost corners and assemble the materials to build a MiniMax from scratch (first mistake). I prepared an inventory of materials from the plans and started phoning. Some hunting around southeastern Ontario uncovered a dusty pile of rough sawn sitka spruce in 1 inch thin planks, a source of aircraft plywood and a second hand Rotax 447 (second mistake). Three days in a friend’s pipe organ building shop reduced a precious 45 board feet of sitka spruce and 7 sheets of a/c plywood to a pile of sawdust and dimensioned materials.
Yellowknife, thankfully, is on a road. So a truck was bought and a trailer frame welded. The trailer frame was to hold a box large enough to contain and transport the MiniMax home from the North on that fateful date not too far off. With the trailer in tow (I would build the “box” in Yellowknife) and the truck loaded with airplane materials and nonessentials, such as a dishwasher and barbecue, we set off from Simcoe, Ontario for Yellowknife, 3000 miles away across Canada.
The trick in finding an apartment to build an airplane in is in not telling anybody you are eyeing up the living room for a 16 foot work bench. The apartment needs to be on the ground floor, have a patio door and have deaf, or very forgiving neighbours. Two sheets of plywood, end to end, on 2×6 joists on saw horses made a very adequate work table with a very important straight edge down the work table face. A large tarp covered the living room and kitchen dining furniture, carpet and sometimes the baby during construction. Wall decorations – designer wing hangings and body parts – were by TEAM Engineering, dust byÖÖÖ.
I would be a deserving homicide victim if I failed to mention the patience and endurance of my partner during this time. Can you imagine being held captive in a two bedroom, basement apartment, in Yellowknife, in the winter time, with a baby and a man crazed by his project? And the dust? It is not too much of an exaggeration to say the first words of our darling daughter growing in the midst of this madness were “dirty, dirty, dirtyÖ..”
The winter passed and spring arrived in “Bug City”. The basic structure was complete and covered, and we were all keen to get the “project” out of the livingroom. So, armed with bug juice that would melt the handle off a plastic power tool, I set to work on the trailer and box in the parking lot. The trailer box was constructed of º” ply and spruce 2×2’s bolted to the steel frame of 2×4 rectangular steel pipe. The box is a whistle over 16 feet long, 6 feet high and five feet wide. The wings go on either side wall and the “project” rolls front first on its own wheels up the rear doors (serving as ramps) into the box. The tail feathers fit into wing stubs on both sides of the trailer box.
Now, some of my more direct friends have uncharitably referred to my creation as the world’s ugliest trailer. This may be so. However, in the truest sense, beauty is only skin deep. With the trailer I can go anywhere and tie downs and storage are not a problem. Lastly, it is secure against weather and the cursed among us who would wantonly destroy another’s property. A trailer is highly recommended.
If any part of this project nearly defeated me, it was the painting. I could not rent paint shop space in town and the cost of paying a professional painter to do the work was prohibitive. So I waited for that fateful day they said I was free to go home, to go South. At last, in Victoria, under a plastic tarp, I finally got to painting. A rented compressor couldn’t keep up to the pressure demands of a standard paint gun, and without a respirator, I thought I would die of asphyxiation and brain damage. A word of advice, get a BIG compressor, large enough to run both a paint gun and a respirator.
But at last, my project was painted and ready for final assembly. A little over a year and a half had passed since I had started. Not bad for an airplane project, by most accounts. Certainly, even without even flying it, I had my money’s worth. Lots of building fun. I estimate about 450 hours for the basic airplane, another 250 for the modifications and another 150 hours for the trailer.
The prospect of flying the “MukTuk”, as I have affectionately come to call the “project” in honour of its Northern origins, kept me awake more than one evening. Reasonably believing more in the original designer’s design skill than in my own, I kept very close to the design specifications. My apprehension was more a general anxiety of having made some tragic blunder. (Was it really sitka spruce? It the fabric tight enough?) It was not unlike the fear before one’s first solo flight – prepared but aware of the consequences of error.
The first day on the field, was a day for “taxiing” trials. At a local (uncontrolled) airport, with permission of the airport manager, I taxied, first slowly, then more quickly, up and down the taxiways. First with the tail down, then with the tail up. Eventually, the inevitable happened – MukTuk, as airplanes are wont to do – took off. Before I knew it, I was just about 4 feet off a rather narrow taxiway in a slight cross wind, wondering whether to firewall the throttle and fly a proper landing approach, or to wrestle it down. Foolishly, I wrested it down. Thank you, instructor Bob, for your lessons in aggressive footwork in the Canuk. I am also embarrassed to report that during a “downwind” taxi run, I lost control of MukTuk and left the taxiway, but luckily without incident. Tsk, tsk, especially in taxi trails, don’t forget this is a tail dragger.
A couple of weeks later, MukTuk, having survived me and the taxi trials, was ready for the “Real Thing”. I chose Hope airport, British Columbia, for its two parallel 4000 foot grass strips. Despite its reputation for rough air, it is known to me from glider training and the two grass strips offered a very comfortable landing opportunity.
Early morning saw me on the field with the “world’s ugliest trailer”. After assembly and a very thorough pre-flight and run-up I taxied into position at the threshold of two seven left. Well. This was it. I had built it, now I had to fly it. No excuse now. I had mentally rehearsed this moment many times beforeÖÖ. Stick full back, centre runway, full throttle, tail up, straight down the runway until she lifts herself off, climb out at 40 MPH, watch altitude and plan for a flame out – right? Wrong. Ö
Full throttle, (holy smokes, this thing accelerates!)Ö start forward pressure on stick to lift tail, LIFTOFF, already!? In less than three seconds I was off, in probably less than a 100 foot ground roll. I didn’t even get the tail off the ground and I was climbing out at thirty degrees. Airspeed 40 MPH, temperature okay, wings still on, might as well sit back, enjoy the ride. Before I passed over the far runway threshold I was at 1200 feet AGL. It seemed seconds later, I was at 3000 feet AGL. I felt secure in a borrowed glider parachute so as I throttled down into cruise attitude and messed around a bit. 4300 RPM delivered 60 MPH and the controls felt like I was flying at a maximum maneuvering speed. I was flying with the cockpit configuration, so for the first time ever, I had the pleasure of open air flight. Stuck out my left arm, and MukTuk started a left turn (that’s interesting!). Slowed to 45 MPH and controls still very positive.
My first landing followed a power on approach. Dead easy. Chop power, round out, hold off, and “plop”, I was down to stay. I practiced the rest of the day doing circuits to 500 feet and power off landings. Flaps with side slip is a very effective way to get down if you are high on a short field, but if you are dead sticking, dump the flaps (watch the airspeed) well before round out and end up flying it on hard. As the designer says, flap landings require power on to give sufficient round out authority.
This is fun flying! I passed the flying summer without event, until the “music stopped” at 2000 feet AGL, over the Town of Hope one beautiful August morning. I made it back to the airport with 200 to 300 feet to spare on a straight approach. A broken ring seized the engine and now the engine is toast. Lesson learned – never fly out of range of a place you’re happy to land in and never buy a used 2 cycle engine.
Few things in life are as worthwhile as a “project”. While working oneself into a state of exhaustion while juggling “project”, work, family and other interests, a project gives the average working man’s mundane life meaning and accomplishment.
TEAM engineering in Bradyville, Tennessee, design and sell the Mini Max kit. This is a great project for the builder of overgrown model airplane kits or for the first time home builder of “real” airplanes. I understand TEAM have a two place machine under development. Check it out.
I made only a couple of embellishments to the original design. I have built the cockpit to afford either open flying behind an oversized windscreen or enclosed flying inside a canopy enclosure. The designer offers a similar kit add on. I added toe brakes by leading the brake cables to some hinged pads atop some “beefed up” rudder peddles. A trim tab was added to the elevator and the pull cord for the engine start is run between the rudder pedals into the cockpit. Instruments are an altimeter, airspeed, tachometer, CHT, EGT, compass and engine hour meter.
My next project is to build floats for “MukTuk”. In this regard, I wish to thank those that responded to my request in “The Recreation Flyer” for information on wooden float designs. Your assistance was much appreciated, but I am still looking for a design that uses epoxy and aircraft plywood. I’ll keep you posted.
To those of you out there at the 500 plus hour mark on your project, I can only offer you my encouragement (and sympathies). For those of you yet to begin your project, I can only ask, “what the heck are you waiting for?”