Photos and story by Jack Cox
Voted the best Low Wing homebuilt and the one with the Best Interior at Sun 'N Fun this past March, Brian Henneman's mildly modified KR-2 obviously qualifies as a candidate for coverage here on the pages of SPORT AVIATION ... as does Brian, himself. Still another of you amazing EAAers who manage to come up with a trophy winner on your very first try at building an airplane, he is most deserving of your figurative applause as you read this article and in actual fact when you meet him at flyins this summer.
Brian began building his KR-2 just before Oshkosh '80 and could have flown it to the next year's Convention. The first flight was on July 23, 1981 and FAA lifted its restrictions on August 6 -- still time for the final weekend of Oshkosh '81. He was sorely tempted, but after a lot of soul searching, decided not to risk a 450 mile cross country until he had acquired the experience with the airplane, its engine and systems he felt he should have. There was Sun 'N Fun the following March and Oshkosh '82 -- reasonably far enough down the road to allow him to work out any bugs that might develop, yet close enough to provide incentive to keep his test program in high gear.
When Brian and his wife, Debbie, touched down at Lakeland in March, they were some 1300 miles from their home in Clarinda, Iowa -- their longest cross-country flight to date. The KR had 112 hours in its logs ... and Brian had about 250 in his, most of which had been in a Cessna 150. A few hours in a Cub and a Super Cub had been his only tail dragging experience prior to strapping into the KR-2. He had done a lot of taxiing and some lift offs into ground effect before attempting his first out-of-the-pattern excursion, however, so when it happened, there were no surprises and no problems. The first flight lasted 30 minutes and several more flights were made that day. The airplane had been built so carefully and so accurately that, to this day, no trim adjustments in any axis have been necessary.
It had also been beautifully built ... which was what initially caught everyone's eye at Sun 'N Fun. The finish was outstanding, the trim scheme was tasteful and the interior, as certified by the judges, was the best on the airport. I've long since learned that an airplane like Brian's is no mere cosmetic job. Start peeling off cowlings, canopies and inspection covers and invariably you'll find the superior craftsmanship running right down to the very first whack the builder put in a piece of spruce or whatever. In fact, it's much easier to get builders to talk about the insides of their airplanes than the shiny exteriors. Brian was no exception.
The KR-2 airframe was built pretty closely to the Rand-Robinson plans -- with the obvious exception of the canopy. The stock R-R canopy is a one piece bubble -- simple, light and perfectly adequate for pilots up to average height. Taller persons, however, often find themselves having to lean their heads inward toward the center of the bubble for a good margin of noggin clearance. This was Brian's problem, and he solved it by ordering a cut down version of the Sidewinder canopy, which he utilized to make a fixed windshield and a left side swing-up hatch, a la Barracuda, Glasair, etc. As you can see in the photos, Brian did an exceptionally good job of blending the flatter style canopy into the lines of the KR-2 fuselage. Look at it for a few minutes and you find yourself forgetting how the original one looks.
N4263Q is powered with an 1835cc HAPI VW conversion, swinging a 52" x 47" Great American prop. This particular engine was the one HAPI owner Rex Taylor brought to Oshkosh in 1980 for display in his booth. Brian came to the Convention with the expressed purpose of buying an engine for his KR, so when he saw this slicked-up showpiece, his quest was over. It is equipped with HAPI's full line of goodies -- starter, alternator, HAPI Headers, engine mount and Super Carb, a Posa modified to include mixture control. (HAPI now owns the Posa carb.) As mounted on the KR-2, it has heat muffs to supply both carb and cabin heat and is plumbed and probed to provide cockpit info on the usual temperatures and pressures, plus CHT and EGT.
The engine derives its sustenance from a fuel system consisting of a 5 gallon tank in each wing, from which gasoline is transferred via an electric pump mounted under the right seat to the 20 gallon fuselage tank. Fuel from the main tank is gravity fed to the engine. Now, with a normal cruise power setting, 150 mph at 4 gph, we are talking about a bladder busting endurance of seven hours (with a half hour reserve, if all fuel is useable) and a still air range of 1050 miles! At $1.20 per gallon for, say, AMOCO unleaded auto gas, that's roughly Chicago to Houston on $36.00 ...which is why efficient homebuilts are now inheriting the sky.
Moving back into the award winning cockpit, one immediately notices the fancy upholstery and dual controls. A "stock" KR-2 has a center stick which either occupant can use, but Brian wanted a dual stick arrangement and heel brgkes (instead of the stock "grab cable"). He also built in flaps and Rex Taylor's modification of the gear latching system -- each of which contributes another handle in the cockpit. The flaps, incidentally have 3 positions -- down to 45 degrees at full extension.
The baggage compartment behind the seats holds up to 20 pounds ... IF the rest of your load is light and properly distributed in the cockpit. The form fitting seats, the fuselage sidewalls and the bottom of the baggage compartment are covered with an attractive Herculon fabric -- the very same pattern and material found on the Henneman's sofa and love seat at home. The seats, themselves, are form fitting ... Brian's form, that is ... and are made of foam and glass. Padding and upholstery cover the top sides, of course. The seats are not fastened to the airframe - they just lie in place, held there by the strapped in pilot and passenger. They are easily lifted out for inspedion and/or maintenance of the control system, fuel pump, etc. Since the seats were molded to Brian's torso, they were terribly uncomfortable for Debbie at first. Some strategically placed foam padding solved that, however.
The instrument panel is pretty well stocked, as you can see in an accompanying photograph ... to the extent that with the taxi, landing, position and strobe light package, the KR-2 has been approved for night flying. Refer to the pictures again and you'll see that the landing and taxi lights are built neatly into the leading edges of the wings, with Plexiglas covers.
The main landing gear is straight off Rand-Robinson's shelves -- gear leg castings, spring bar, hardware, etc. Motorcycle cables were used, however, to actuate the brakes via the heel pedals. N4263Q's tailwheel is an industrial supply wheel, drilled and bored out for installation of ball bearings. Has worked perfectly, Brian says.
One of the few changes made elsewhere in the airframe involved the cowling. The first one, a foam core composite sandwich, was built as per the plans. It developed some bubbles from the engine's heat, however, so Brian built a new one, using the original as a male mold. It is simply layers of fiberglas, with no foam core, and he says he is a lot happier with it.
The engine is very carefully baffled and is fitted with an oil cooler (mounted on the right side) -- with the result that the HAPI runs nicely in the green on both the CHT and oil temperature gauges.
When I asked about the KR's superb finish, Brian said he wanted to preface his remarks with a recommendation that everyone building ... or contemplating building ... a composite aircraft of any type read Bob Waiters' article, "Finishing Composite Aircraft" in the February 1982 issue (page 23) of SPORT AVIATION. "It's right to the T of what you have to do," Brian says. "It just depends on how much patience you can muster to get the finish you want."
Brian used a combination of Dynel and 6 ounce fiber glass cloth on his KR. The flying surfaces, the wings and tail surfaces, plus the nose cowl and main fuel tank are built up using fiber glass and Dow 330 epoxy and hardner (from Wicks). Dynel, which is stretchy and therefore easy to apply to compound shapes, was used on the turtle deck and places like the inside of the wheel wells.
The wingd have two layers of glass ...just because Brian wanted two layers. The foam underneath is methane, glued in place with Rand's 5 Minute Epoxy.
N4263Q tips the scales at 601 pounds (empty). With the prop currently in use, it indicates 150 mph at 3200 rpm and tops out at between 160 and 165 at 3600 rpm. With just himself aboard, it stalls at 45 mph and around 50 with a passenger. Solo, Brian climbs at 95 mph, which yields an initial 1000 fpm. With a passenger, the rate of climb drops to around 500 fpm. If that much of a decrease surprises you, consider the percentage of either the empty or gross weight of so light an airplane a passenger represents. This is a factor that must be kept in mind when flying any of our lighter, lower powered homebuilts.
Brian says he comes over the runway threshold indicating 70 mph and touches down between 55 and 60. He normally makes wheel landings and lets the airplane roll until the tail comes down on its own. Once down, he pins it there with full aft stick for taxiing. The wheel landing is used because you can't see ahead in the 3-point or full stall landing attitude. A KR-2 has a long, fairly flat nose and you sit (recline) quite low in the cockpit -- a combination that is going to sell a lot of tri-cycle gears for Jeannette Rand when she gets her new one on the market.
As I indicated in the beginning, the KR-2 was Brian's first homebuilt project ... his first homebuilt AIRPLANE project, that is. Unlike some of our EAAers who, incredibly enough, have never so much as built a foot stool before tackling an airplane, Brian did come to the task well prepared. He was, in fact, a TRUE homebuilder -- having built his home and a 24'x40' fully insulated, heated shop. Not only that, he built up a custom van that won a national award in 1975 ... and a 3 wheel, VW powered, fiber glass bodied.., er, vehicle "... before airplanes became the challenge in my life."
Brian was a turbine engine mechanic on helicopters in Viet Nam ... and out of sheer boredom often volunteered to fly as a door gunner. He had gone through all the army's training schools for both turbine and recip engines. Today, he is an electrical/maintenance supervisor and tool room supervisor at a large ball bear- ing manufacturing plant in Clarinda ... which in case you've never heard of it, is a town of about 5,500 souls located in southwestern Iowa (about 60 air miles SE of Omaha). I asked Brian a question I ask every builder I interview... "Why did you pick this particular design to build?" He answered, "I picked the KR-2 because of the VW engine. I had previous experience with them and I'm convinced it is a super engine. The airplane was fairly small, it was made out of materials I had worked with before and I liked the looks of it. Everyone I talked to said it was a nice flying airplane ... and this has proven to be true."
And since his track record of recent years showed the unmistakable symptoms of a confirmed buildaholic, I wanted to know what Brian's next project would be. I wasn't surprised at all when he revealed he was already at work on a Sidewinder.
I also won't be surprised if a couple of years from now I'm sitting in an audience at Sun 'N Fun or Oshkosh and hear Brian Henneman being called to the stage to receive still another armload of trophies.