I can't yet say whether all of the changes I made were for the better. The longer wing certainly was-but that's no surprise, since wingspan is almost always beneficial. The composite construction proved to be much more complicated and time-consuming than I anticipated. No doubt it's quicker for very simple airplanes and for prefabricated kits, but for a complex airplane like this one it's more difficult than metal. This airplane is, however, a little cleaner than the first, and it's likely that the credit belongs to the smooth, compound-curved surfaces and the lack of external antennas.
The fixed stabilizer seems fine; I won't know for certain until I've flown with a forward CG and full flaps. The sidestick, with its low mechanical advantage, is probably mainly to blame for the rather stiff-feeling ailerons. On the other hand, it leaves the floor completely clear, and with no console between the seats you can move your feet and legs about freely and stretch out on long flights. I expect that some day I might change the hinge points on the ailerons in order to provide them with some aerodynamic balance; but for the time being they're acceptable.
The updraft cooling is adequate, but it's not as good (at least not yet) as the downdraft was. I was surprised and disappointed that it wasn't immediately superior. I expected the placement of the cooling air exits near the front of the top cowl-a location that makes some people mistake them for inlets-to yield a powerful extraction effect, especially in climb. Maybe it does, but I still have work to do on the cooling; it's a complicated business.
The wing area, 106 square feet, which is the same as the old Melmoth's, is quite a bit less than the 170 or so typical of production four-seaters. John Roncz designed the low-drag laminar-flow airfoils, of which three are used, tapering from 18 percent thick at the root to 13 at the tip. They are similar to the ones on the Rutan Catbird, an airplane that mine in many ways resembles (by coincidence; neither of us was aware of the other's design). The tricky part of designing the airfoils was to avoid a premature tip stall on a strongly tapered wing with a very short tip chord (20 inches) and little twist or "washout." Roncz succeeded brilliantly; the stall begins at the root and progresses outward, as if the wing were rectangular.
The wing skins are principally of foam-cored sandwich, about three-tenths of an inch thick, with a load-bearing graphite inner skin and a just-along-for-the-ride outer skin of glass fiber. The spars are graphite. The entire wing, except for the flap cove and the extreme leading edge, is a fuel tank with a total capacity of 142 gallons. The outer panels bolt onto a central wing box that is integral with the cabin structure and protrudes two feet beyond the sides of the fuselage. The main landing gear is mounted in that box and the wheels retract under the seats-a feature that, combined with upright seating, obliges the cabin to be a couple of inches taller than it might otherwise be; but I could not get the 600 x 6 tires to disappear completely into the wing root.
I made the wing skins in four different female molds, and because of the lack of space in the garage I had to destroy each mold before making the next. Luckily, the parts fit together when I joined them. Other than the wings, cowling and canopy frames, however, I built the airframe without molds, by laying up glass- or graphite-epoxy over shaped plastic-foam cores. Two or three years into the project I discovered vacuum bagging-curing parts inside an evacuated plastic bag, so that excess epoxy is squeezed out by atmospheric pressure-and after that I vacuum bagged almost everything, whether it made sense to do so or not.
At Mojave, prior to first flight, the airplane weighed 1,397 pounds empty. By the time it's fully equipped, it will weigh about what the first Melmoth did-1,500 pounds. Proportionately, that's a reduction-remember, it's a bigger airplane, with heavier landing gear and canopy and a longer, more slender (and therefore theoretically heavier) wing. I hesitate to attribute the improvement to the composite structure-small composite airplanes usually turn out heavier, not lighter, than metal ones-but I don't know where else to put it.
People are often curious about the cost. I already had the engine, propeller, instruments and avionics from the previous Melmoth, and various friends were kind enough to donate materials, like graphite cloth, that would have been very expensive to buy. On average, I spent less than $1,000 a year on the project until it was close to flying and I started having to overhaul or repair long-stored items. I suppose I put about 500 hours a year of labor into it, some years more, some less.
It's still very much a work in progress, and will remain one for a couple of years to come. The flaps and speed brake, although built and installed, are not yet operable. The nosewheel doors are not installed, nor are the cowl flaps and wingtips. There are no nav lights or panel lights. Window seals, ventilation, heating, oxygen system, automatic fuel tank switching and intercom are among the functional amenities still missing.
As a project like this nears completion, the designer-builder finds less and less freedom of movement in it. A restless inner me, like some poor baffled mental patient who all day long repeats an abortive gesture, keeps wanting to return to the drafting table and the computer and to the thrilling, seductive first steps of design, when each line laid down is pregnant with new promise and beauty. But twice is enough; I don't think I'd better go around again.
Also read these related stories:
Melmoth Flies… Again!
Cleaning Up Melmoth
Five Years With Melmoth 2