Airplane Pdq 4v2l19

(Photo by Jack Cox)

An Airplane That's

by Jack Cox

Instead of folding his tent and fading away into the night, Wayne fought back. In order to bring back the fun, close competition and low

>ACK IN THE heyday of the go-kart and micro midget mania, Wayne Ison (EAA 13187) was into the scene up to his ear lobes — just as much so as he is involved with homebuilt airplanes today. Somehow, between building, maintaining and racing his own karts at tracks all over the upper mid-west, he even found time to write the "how to" go-kart

articles for Science and Mechanics magazine. It was tremendous fun for a time, Wayne says today, but as competition grew hotter sophistication and its hand-maiden, added costs, started entering the picture . . . and soon the fun was evaporating at about the same rate as the blue smoke from those screaming little two cycle mills that propelled those just barely guided missiles. 50 JANUARY 1975

cost, he succeeded in forming the "West Bend Class - Bushings Only"

category. This gave the beginner a chance to get into kart racing at a level of mechanical sophistication that was easy on his wallet and simple enough so as to serve as a good starting point on the learning curve involved in successfully operating, tuning and overhauling the two cycle engined karts. Once a racer

had mastered the West Bend jobs and still wanted more, he could progress to the faster, more expensive hardware . . . and his basic training would not have cost him his life's savings. This experience made an indelible impression on Wayne Ison and was carried over to aviation once he became involved with EAA and home-

building. He restored a Rearwin Skyranger about ten years ago and started a Fly Baby but sold the fuselage before it was completed. Wayne enjoyed flying the Rearwin and found the crafting of the Fly Baby satisfying . . . but somehow all this just didn't fill the bill. While sorting out in his mind all the plusses and minuses of his aviation career up to that point, he took time off to do some REAL homebuilding — a new house for his family. Wayne is a mechanical engineer for Keltec in Elkhart, Indiana. His workaday activities involve deg industrial floor maintenance equipment — floor polishers, cleaners, rug shampooers and the like. He is comfortably settled in his job, his new home and the life of his community. Flying, for him, is strictly a recreational activity. Despite having learned to fly at Three Rivers, Michigan under the G.I. Bill quite a number of

years ago, he is still a low time pilot and it's rare he flies anything larger than a Cessna 150. In a word, Wayne Ison is a living, breathing stereotype of the typical EAA member . . . up to a point. He differs from many of us in that he has the self discipline to coolly analyze his dreams and his real needs and come up with a plan of action that contains a nice balance of both that he can live with. Some of his conclusions about himself were that he did not need a fast, expensive to maintain, cross country airplane. This ruled out most of the store bought fleet. What he really wanted was something that was fun, easy to fly and something that would satisfy his need to create, build and tinker with — this pretty well spelled "homebuilt." After a long look at the do-it-yourself world Wayne came to the further conclusion that what he had seen happen in go-karting was also happening in aircraft homebuilding — a lot of new designs were becoming more complicated, more expensive, thus making it harder for the average person, particularly a rank beginner, to break into the game. He had no quarrel with any design or designer — he thought the variety of designs available to builders was tremendous. It's just that he did not believe any of them started on a simple enough level. Characteristically, he set out to do something about the situation . . . he would design his own airplane. PDQ-1 Wayne's first effort might be described as an attempt at the absolute minimum powered airplane, a VW powered machine with nothing more than a couple of lengths of aluminum channel bolted together like a bed frame to serve as a fuselage; to this were attached his left over Fly Baby wings and a rudimentary tail section, all strung together by a cobweb of aircraft cable. The pilot's seat was suspended from the bed frame fuselage and the VW engine was quite literally sitting in his lap. Named the PDQ — because it was — this sort of un-Sanforized Bleriot was flown up and down a runway in ground effect a number of times, but its greatest contribution was as a trial horse for Wayne's ideas. He learned a lot from building the PDQ and came to realize the direction in which he would proceed from it. The engine from the PDQ was later used to power an experimental Parafoil, but was returned and bolted back on the original airframe in time for it to be brought to Oshkosh '74. The plane was displayed as the PDQ-1 — because now there was a PDQ-2. (Continued on Next Page)

(Photo by Dick Stouffer)

The PDQ-1 at Oshkosh 74.

Designer Wayne Ison holds up the tail of his PDQ-2 so EAA photographer Lee Fray can shoot a close-up of the two cycle Rockwell JLO engine. SPORT AVIATION 51

PDQ . . . (Continued from Preceding Page)

PDQ-2

Started during the Christmas holidays before the 1973 Oshkosh Fly-In, the PDQ-2 was completed in just four months of steady evening and weekend work. About the only thing around with a simpler fuselage than the PDQ-1 was the Bensen Gyrocopter — so, the fuselage of the PDQ-2 was modeled after it to a great extent; in fact, the 2 inch square, 1/8 inch wall thickness 6061-T6 main fuselage were purchased from a Bensen dealer. One 41" length was laid out as a keel and a second piece 40" long was cut to serve as a vertical mast rising at a 3° rearward angle from the keel. 13 inches up the keel a 74 inch tail boom was made to extend straight aft, braced with two lengths of 1 inch O.D. x .065 6061T6 aluminum tubing, one from the top of the mast down to the boom and the other from the aft end of the keel up to the lower side of the tail boom. And that, by golly, was it — everything else, like wings, engine, seat, wheels, tail, fuel tank, etc., attaches to this super simple frame. A professional welder was paid $20 to heliarc the 5 pieces of aluminum together after Wayne ran a little cost/weight analysis which revealed that the aircraft bolts, 4130 gusset plates and the time necessary to measure for and drill bolt holes would cause the frame to be heavier, more costly and time consuming to build as a bolt together unit. The weight increase would have been especially critical. The fuselage frame was designed in such a way that two go to every stress point, so that one can fail without a resulting catastrophe. It was built during one weekend and the only power tools used were a drill press and a Sears belt sander . . . plus the welder's outfit, of course. For a landing gear Wayne stretched Steve Wittman's 40 year old leaf spring idea to it's ultimate limits — not only does the tri-cycle set up use a leaf for the mains, but even the nose gear is mounted on a leaf that sticks straight out to the front like spear at the ready. It's nothing more than a piece of 2024-T4 aluminum 30 inches long, two inches wide and 1/2 inch thick. This leaf is attached to the top side of the front of the keel with one lousy bolt and a couple of spring clamps. In keeping with Wayne's desire to make each component serve as many purposes as is practical, the rudder bar is even attached 11 1/2" out on the leaf, with a steering pushpull tube extending from the rudder bar out to the nose gear — which is nothing more than a 6 inch aircraft 52 JANUARY 1975

tailwheel or a suitable, similarly sized industrial unit. You stand there and look at that whole ridiculous rig and

then sanded. Any low spots are filled with automotive spot putty, a final sanding and priming is done and the

it's enough to make you sick to your stomach . . . that you didn't think of

color coat is applied. Throughout the

something so beautifully simple yourself! Wayne's prototype PDQ-2 is equipped with 5 inch go-kart wheels with 3.40/3.00-5 two-ply tires. Originally, the plane was not equipped with brakes, but they were added for its 1974 appearance at Oshkosh.

of the really troublesome areas. An amazing amount of weight is added to homebuilts by many builders who too enthusiastically strive for super

If plans-built versions are to be flown off pavement, the lightest kart or mini

bike brakes one can find are recommended. I'm sure more than one smart alec has already suggested to Wayne that he apply a layer of brake lining

material to the soles of his shoes so he can simply drag his feet on roll out

— and that by dragging just one at a time, he can have the advantage of differential braking. Deliver us, Lord, from our tormentors! One thing Wayne wanted to to do with the PDQ-2 was incorporate some new materials and building techniques in its construction, because from the beginning he had not only

the EAAer but also high school students in mind as builders. He wanted the aircraft to be a teaching tool for schools and a first stepping stone for those who would later go on to more sophisticated designs. After seeing Ken Rand's foam and Dynel KR-1, the old PDQ-1 Fly Baby wings were forgotten and the foam began to fly (ouch!). The PDQ-2 wing s are four spar affairs with plywood former ribs at the inboard and outboard ends, interspersed with 7 foam ribs (on the original 16' 6" wing). The spars are solid spruce boards consisting of a 1/4" thick leading edge spar, a 1/2" main spar, a 1/2" rear spar and a 1/4" aileron spar. 3/4" thick 4' x 8' sheets of ordinary 2 pound density Styrofoam or Urethane foam are bonded over the ribs. Numerous spanwise saw-cuts are made about halfway through the foam sheet on the bottom side to facilitate bending the sheet to the contour of the rib without breaking it. Solid strips of foam are bonded to the leading edge spar and are

PDQ-2 plans Wayne cautions builders again and again to watch the weight build up, and finishing the wing is one

smooth finishes — and on an ultraultra-light like the PDQ-2, you just

can't do this if you expect it to climb beyond ground effect. Wayne's finish on the prototype looks great, proving you don't have to overdo it. The PDQ-2 has full span ailerons and they are nothing more than a 1/4" thick spruce spar with an inboard plywood rib and ply gusset — the rest, including the outboard tip rib, consists of shaped foam and Dynel. The rakishly swept fin and rudder and "T" mounted horizontal stabilizer and elevator are built up just like those on the KR-1, W.A.R. Fw. 190 — and how every other foam and Dynel tail surface will undoubtedly be made. The single-spar-and-foam system can't be improved upon. Once you get to the pilot's . . . well, I was going to say "cockpit", but

somehow that hoary old aviation term seems competely inappropriate when it comes to identifying the area in which the pilot does his work in something like a Breezy or, in this case, the PDQ-2. It's certainly anything but a pit. Perhaps "pilot's precipice" would more accurately describe the view one has between his knees from a thousand feet in a PDQ-2. So, as I was saying, once you get to the pilot's precipice, things are both spartan and clever. A small instrument inclines forward between the pilot's legs containing an airspeed indicator, altimeter, a little Westach electric tach and the master switch. The rumor is unconfirmed that

of applying his Dynel and epoxy than

the PDQ crew gets around the com requirement by wearing a hunter's wrist watch-type com while flying. The edge of the precipice over which the pilot dangles his legs out to the rudder bar is a wide tray which doubles as a seat and the mount for the fuel tank. Originally, fuel tanks were built-up foam and Dynel cavities in each wing root, but they proved to be leaky so an off-the-shelf

does Ken Rand, War Replica Aircraft, etc. Rather than just laying up the

been incorporated. A tiny motorcycle

cut down to conform to the shape of

the NASA 63 2A 615 airfoil. Wayne has a little different method

Dynel over the foam and squeegeeing

epoxy through the weave, Wayne first bonds the edges, then shrinks the cloth taut with an iron. Thin resin is squeegeed into the cloth and lightly

sanded after it has cured. A second coat containing micro spheres is the squeegeed in, allowed to cure and

6 gallon outboard motor tank has battery is mounted just under the pilot's right knee. Anytime you ed the PDQ-2 at

Oshkosh there was a little semicircle of suppliants on their knees around

the seat of the aircraft apparently seeking wisdom of some sort. The unique sidewinder stick/throttle was

the object of their supplication. Attached to the keel just behind the vertical mast, by a clever sort of gimbal arrangement, the stick curves out and around the seat, falling right to hand as they say in sports car circles. The arcs inscribed by the stick as one moves it up and down and from side

to side result in a rather odd feeling, but Lowell Farrand, the pilot who has the most time in the prototype, says this monkey motion is easy to adjust to. The stick's handgrip is a motorcycle twist-type throttle, spring loaded to return the engine to idle if the grip is released . . . still another component serving a double function. And now, up the mast to the engine. Initial calculations indicated 90 pounds was the absolute limit that could be tolerated on top of the mast and less would be highly desirable. A McCulloch could have been used, but Wayne was looking for something smaller. The eventual choice was a two cylinder, two cycle JLO of GOOcc capacity imported from Europe by Rockwell. This particular engine had a singular advantage over others considered in that having been developed specifically for a ground effects machine, it came equipped with a propeller hub and the proper thrust bearings — no major modifications were necessary for aircraft use. The complete engine installation, including the propeller, weighs 70 pounds. The JLO develops 45 hp at

two cycle engines. However, tests revealed the JLO was turning up to rated power, measured thrust seemed adequate and initial acceleration and lift-off were sprightly enough — but it just didn't want to climb. Then one wintery day they found out why. Flying in a snow shower, Lowell

tain the turbulent wake caused by the pilot's head and the mast. It worked like a charm — now the little bird would accelerate, rotate and climb right out. Unfortunately, these modifications were significant enough that a new test time was assigned so that, combined also with some down

happened to look out across the wing

time for re-license, once again the

and noticed that he could actually see the pattern of the air flow over the airfoil —just like in a smoke tunnel except here snowflakes were taking the place of the smoke. The dark blue wing was a perfect background for viewing this phenomonon. Lowell very quickly saw that his head and the engine mast were forming a Vshaped wake that spread back and outward over both wing s very effectively spoiling the lift over a great percentage of the wing. Further, increasing the angle of attack — as when climbing — created a larger and larger wake, in effect reducing the effective aspect ratio to almost nothing. No wonder

PDQ-2 was grounded (except for their Indiana test area) when Oshkosh '74

it wouldn't climb. A little more experimenting in the world's largest and least expensive wind tunnel, as Wayne likes to say, resulted in some modification to the airplane. First, the wing was lengthened from 16 feet 6 inches to 18 feet 6 inches, Cessna type wing tips were added and a couple of fairly large plywood flow fences were installed near the wing roots to con-

rolled around.

The little bird was at Oshkosh, nevertheless, and Wayne had plans for sale for $20.00 a set and was doing a brisk business — particularly among the large Australian group that came to Oshkosh. They consist of nine 24" x 36" sheets and are quite complete. Especially helpful to the builder are the addresses of all the sources Wayne is aware of for materials to build the airplane—JLO engines from Venture Aero-Marine, P.O. Box 5273, Akron, Ohio 44313 and PDQ-2 materials kits from Aircraft Spruce and Specialty Co., Box 424, Fullerton, California 92632 and Rotor-Hawk, Inc., 9007 Henderson Rd., Goodrich, Michigan 48438. It was good to see that the plans contained such items as control system details, a complete bill of material and even a layout showing how to cut ribs, fin, rudder and aileron material from 4' x 8' sheets of foam with the least amount of wastage. A lot of (Continued on Next Page)

5500 rpm's (it is direct drive) with two

carburetors and 35 hp at 5000 rpm's. The only problem with the engine is that as of Fly-In week at Oshkosh, Rockwell was no longer producing it

— which means that when stocks are sold, PDQ-2 builders will have to come up with a suitable substitute. Wayne carved his own propeller, a 44" x 17" unit that produces 175 to 180 pounds of static thrust. Lowell Farrand (EAA 35370) of Goshen, Indiana, a good friend of Wayne's and an experienced pilot, did the initial test flying. The first flights were runs in ground effect up

and down a local grass runway. The required test time (75 hours) was not flown off in time to allow flying at the 1973 Oshkosh Fly-In, so the plane was a static display there. Upon returning home, more testing was done, with the first flights around the pattern being made during early fall. Lowell and Wayne were having so much fun that, despite the lack of even a windshield up front, flying continued on into the winter . . . and this

proved to be a fortunate thing. Initially, some aspects of the PDQ's

performance were not up to expectations, mainly rate of climb. This latter deficiency was first laid to the engine — despite Wayne's expertise with

(Photo by Jack Cox)

A Bensen gyrocopter pilot would feel right at home here.

PDQ . . . (Continued from Preceding Page)

building tips are also written right on the plans sheets. Although Oshkosh Convention goers have yet to see the PDQ-2 fly, it is a familiar sight to EAAers in the Elkhart area, buzzing around like a big blue bumblebee. Minneapolis EAAers get to see the first plans built PDQ-2 in action. This one belongs to Gene Louismet (EAA 1490), 8718 West River Rd., Minneapolis, Minnesota 55444, who at the time of the 1974 Oshkosh Fly-In was starting a second one. Hopefully, all of us will be treated to perhaps a couple of PDQ-2s flying at Oshkosh '75. Now, let's step back from the nuts and bolts examination of the PDQ-2 and consider its position in the overall sport aviation scheme of things. Ever since that day in March of 1909 when Alberto Santos-Dumont sputtered aloft in his floppy-winged little Demoiselle, tiny, low powered airplanes have been an enduring fixture of the worldwide aviation scene. Super lightweights such as the Italian Pegna-Bonmartini Rondine of 1923 and the English Electric Wren, a star of the famous 1923 Lympne lightplane trials, actually flew on 7 and 8 hp engines. During the bread line and apple stand days of our Great Depression here in the U. S., pilot's had to forego their beloved but gas-guzzling Travel Airs and Wacos for little put-puts like the 36 hp Aeronca C-3s and 37 hp E-2 Cubs. Today, the EAA movement is focusing worldwide attention on tiny, personal airplanes. It is possible, however, that we are seeing the beginnings of something new with the PDQ-2. Most of the low powered aircraft of the past have been born of economic necessity — except for those homebuilders who are simply fascinated with tiny airplanes. Most were actually substitutes for the big, powerful aircraft owners really wanted but couldn't afford. Today we are seeing a situation that is about 180° out — a guy who owns a Baron for business, a Pitts for serious fooling around and when he sees a PDQ2, thinks, "What a blast! I gotta have me one of those toys!". By way of analogy, these people are just like their neighbors who own a Continental, a Porsche and a trail bike for roaring into the woods to terrorize the local wildlife. The PDQ-2, then, may be the harbinger of a "third level" type aircraft, a true recreational vehicle of the air. Most aircraft, and particularly most homebuilts, have always been used almost entirely for recreation but they have been in what we might term the "second level" — or in the "sports 54 JANUARY 1975

car" category to use our analogy again. The PDQ-2 is to aviation what the trail bike, snowmobile and allterrain vehicles are to land transportation. Of course, you can't so conveniently pigeon-hole airplanes anymore than you can land vehicles or people . . . especially people. There are those whose only vehicle is a sports car just as there are pilots whose only plane is a Pitts — and by the same token there will be many who by choice or necessity will own only a PDQ-2. At any rate, there is definitely a place in aviation for the properly designed super lightweight recreational vehicle of the air. There always has been. The only reason we have not always had large numbers of this type of aircraft is the lack of a reliable, inexpensive and, very significantly, lightweight engine (for weight and balance considerations). With what we know today about structures and new materials, think what our designers could come up with given a 40 hp engine weighing about 50-55 pounds or so and small enough to fit in the proverbial bread box. Jim Bede has proven there is a very large market for relatively low cost, high perfor-

mance sport planes. Think of the possibilities of an even less expensive trail bike or snowmobile of the air. Such aircraft could have a redeeming social virtue, also, in the fuel savings realized by pilots who could do their late evening fun flying in their PDQ-2, or such, instead of in their Bonanza. You can get in on the ground floor of this new phase of fun flying with Wayne Ison's PDQ-2. PDQ-2 SPECIFICATIONS

Span . . . . . . . . . . . . . . . . . . . . . . . 18' 6" Chord . . . . . . . . . . . . . . . . . . . . . . . . 42' Airfoil . . . . . . . . . . . NASA 63 2A 615 Wing Area . . . . . . . . . . . . 64.75 sq. ft. Wing Loading . . . . 6.5 lbs. per sq. ft. Span Loading . . . . . . . . . . . . 22.7 lbs. Empty Weight . . . . . . . . . . . . 218 lbs. Gross Weight . . . . . . . . . . . . . 421 lbs. Top Speed . . . . . . . . . . . . . . . . . 80 mph Cruise . . . . . . . . . . . . . . . . . . . . 70 mph Rate of Climb . . . . . . . . . . . 400 fpm + Stall Speed . . . . . . . . . . . . . . . . 46 mph Engine - Rockwell - JLO - LB-600-2 Source: Wayne Ison No. 7 Alpine Lane Elkhart, Indiana 46514

(Photo by Jack Cox)

Lowell Farrand and the PDQ-2.

Why is the PDQ-2 quick? The stark simplicity of the basic fuselage is perhaps the most succinct answer — just five pieces of aluminum, plus a few brackets and fittings.