Melmoth Flies? Again!

This is it: the end of a 21-year countdown. The 9,600-foot Mojave runway stretches out in front of me, the chase plane is coming up from behind. It's clear and calm this November 1st-the day when, as I heard someone explain yesterday on NPR, "the barrier between the living and the dead is thinnest."

"Go!"

Light at 1,800 pounds, and with 1,000 pounds of static thrust, Melmoth 2 pulls forward rapidly as the manifold pressure swells to 38 inches. Rotating at 80 knots, the airplane continues to accelerate and settles into a steady climb at 110.

"You're clean," says Mike Melvill, the chase pilot. Nothing falling off, no smoke, no black liquids running down the belly.

It's odd how these moments confound anticipation. In the weeks prior to this one I've mentally rehearsed every imaginable catastrophe-collapse of the landing gear … failure of the engine mount, wing spar, flight control system or empennage … flutter … engine fire. You name it, I've worried about it. I've examined my own possible death from every angle, including the effect it would have on my 14-year-old daughter's grades in biology. I've paid an unusual number of visits to the bathroom this morning. But now that I'm airborne it comes down to the familiar sensations of flying an airplane as I've been doing for the past 40 years. The moment of becoming airborne is not one of climactic excitement; instead, it releases the stored-up pressure of a sort of negative excitement, letting relative calm flow back in. In the first few seconds aloft most of my fears have evaporated. And so later when people ask, "Was it exciting?" I will have to say, honestly, that no, it was not exactly exciting-it was more just a great relief.

Some time before the first flight Burt Rutan visited the hangar, which is a couple of hundred yards away from his prototype shop, Scaled Composites. He observed that I should definitely have a chase plane for the first flight in order to get a video-which, he said, "your family would like to have, even if it goes well." Actually, he now says that it was I who added the "even if" clause. He and I are about the same age, an age at which who said what a couple of weeks ago begins to be less clear and, for that matter, less important. But whoever said it was right; it did go well, but I, at least, still haven't tired of watching that video.

To recapitulate the road that led here … After several years of false starts, between 1968 and 1973 I designed and built a two-seat airplane that I called Melmoth. I flew it a little over 2,000 hours in nine years, visiting some faraway places, including Europe and Japan. I believe it was, in 1976, the first homebuilt airplane to fly nonstop from the United States (Cold Bay, Alaska) to Japan. Melmoth was destroyed in 1982 when, while holding short of the runway, it was struck by a landing Centurion that was having problems of its own. A year before that I had started working on an all-composite four-seat fuselage for Melmoth; now that project became a completely new airplane. For some reason it took me 21 years to get it flyable-I won't say finished. This is the airplane-same name, same N-number as its precursor-that made its first flight on November 1, 2002.

The procedure for licensing an amateur-built airplane involves a single inspection by an FAA inspector or a Delegated Airworthiness Representative (DAR). (Periodic construction and "pre-closure" inspections are no longer required; a scrapbook of snapshots is enough.) The DAR is a qualified but non-governmental person enlisted to lighten the FAA's workload in a world increasingly swarming with amateur-built airplanes. He is entitled to charge a fee, usually a few hundred dollars, for his services

Having passed that inspection, whose purpose is mainly to catch discrepancies that the builder may have overlooked and make sure all the papers are in order, the airplane receives a certificate of airworthiness and a set of so-called Phase One flight restrictions limiting the area in which it may be flown. Phase One may require as little as 25 hours of flight testing (for airplanes with certified engines and propellers) or 40 or more for ones with uncertified propulsion systems.

On finishing Phase One, the builder makes a logbook entry to the effect that he has completed the required flight testing period and found the airplane to be safe. From then on he can operate the airplane more or less like any other, the principal limitation upon amateur-built airplanes being that they may not be used to carry passengers or cargo for hire. At the same time as the airplane is licensed, the builder receives a repairman's certificate that entitles him to perform and sign off annual "condition inspections" on that airplane only.

For the first three weeks of its flying career, Melmoth 2 made little progress toward flying off its 25-hour restriction. The first problem was excessively high induction air temperature. At least that seemed to be the problem, until I discovered that I had mislabeled the toggle switch that determines whether the gauge shows induction air temperature or oil temperature. The problem then suddenly ceased to be inexplicably high air temperature and became inexplicably high oil temperature.

In flight the oil would quickly heat up to its redline temperature of 240°F; but after I landed, I could put my hand on the oil cooler and the oil filter, which are in series with one another in the lubrication circuit, and they would be barely warm. It was evident that no hot oil was going through the cooler; it was less evident why this would be so. The most likely suspects would be the vernatherm valve, a thermostatic control that sends oil to the cooler only after the engine has warmed up, and the cooler itself, whose small passages could perhaps have become obstructed with some kind of polymerized gunk after sitting for more than 20 years. A third possibility was that the plumbing to the externally mounted oil filter was reversed, so that oil was attempting to flow through the filter, which is a one-way street, backwards. I satisfied myself, by careful inspection of the plumbing, that this third possibility was not, in fact, responsible.

Well, it was responsible, in fact, but I didn't find that out until I had removed the presumably clogged-up oil cooler from the engine. Its innards turned out to be pristine-no polymerized gunk in sight-but my misreading of the internal plumbing became obvious the moment the cooler came off.

On November 20th I was finally able to begin building time in earnest.

In flight testing, first impressions don't mean much. I've often noticed some characteristic or other the first time I flew an airplane, only to have it mysteriously vanish as my experience with the airplane grew. Only by patiently repeating maneuvers and recording data do you approach the real truth. By the time this reaches readers, I will probably have changed my mind about half of what I think now. But for the time being, first impressions will have to do.

Stick forces are on the firm side, but not unpleasant for a cruising airplane. Stability is very good; in the first-flight video Melmoth 2 looks as steady as an airliner. If there is any tendency to drop a wing, I haven't noticed it yet; but on the other hand a few gentle rudder pulses haven't shown much dihedral effect, as would be indicated by the advancing wing coming up when you yaw the airplane with rudder. It's desirable for an airplane to roll when yawed; that response is related to its tendency, when flown hands-off, to stay on heading rather than gradually roll into a bank. With unusual prudence, I left 10 inches off the end of each wing in order to be able to adjust the dihedral effect by tilting the wingtips; but more testing will be needed to see whether any such tilting will really be needed.

The first time I retracted the landing gear I had a nerve-racking 10 minutes trying to get it back down and locked. The aerodynamic drag of the nose gear is more than the lowering system, which has a poor mechanical advantage, can handle; I had to slow the airplane to 80 knots and reduce the power to idle in order to lock the gear down. The usual solution to this problem-mine is not the first airplane to experience it-is some kind of spring (for instance one of those gas springs that hold up the rear hatches and trunk lids on cars) to help push the nose strut down. Another, more complicated possibility is a supplementary hydraulic cylinder for the nosewheel-at present all three gears are mechanically interconnected and are operated by a single cylinder. In any case, it won't be hard to find a fix. For the time being, I drilled a hole in the nosewheel well and am carrying a four-foot-long aluminum pole in the cabin with which to poke the nose gear down if all else fails.

Another problem is the pitch trim. Initially, concerned about the stick forces in pitch that might arise from the combination of a fairly large elevator with a short sidestick, I designed the elevator trim tabs to do double duty as servo tabs. A servo tab is one that deflects oppositely to the main surface, reducing the effort required of the pilot. The problem is that servo tabs apparently don't make very effective trim tabs. It may be necessary to modify the tab linkage to eliminate or reduce the servo action; for the time being, however, I can live with limited trim authority.

The most troubling problem so far has been the engine cooling. Melmoth 2, which had updraft cooling, cools adequately, but when you consider that I'm flying at low weight and moderate OATs, adequately isn't good enough. Melmoth 1, which has a downdraft system, cooled perfectly even under the most adverse conditions of high power, low forward speed and high air temperature. Famously, if it ain't broke you shouldn't fix it; but I thought I could improve a good thing still further. The reasoning behind the redesign of the cooling system is too convoluted to go into here-you can read about it at length, if you wish to, at the website dedicated to the airplane, https://www.melmoth2.com/-but suffice it to say that although I still think the reasoning behind the updraft system is sound, a bunch of little details may collude to undermine it. I will simply have to attack the difficulties one at a time and see whether I can overcome them. Fortunately, I'm beginning the flight test program in late fall, and so can look forward to several months of cool weather in which to experiment.

If the first flight was not so much a thrill as a relief, it had nevertheless an emotional resonance that, like some face glimpsed in a crowd, I felt I knew but could not place. For several days after it-the feeling faded slowly, like the shimmering harmonics of a bell-I would at odd moments, with a mixture of incredulity and elation, breathe silently to myself, "It's flown!" It must have been the same after I flew the first Melmoth, but I've forgotten that. Still, I thought there was something else familiar about this feeling of gaiety and wonder-and finally I realized what it was. It was the feeling I had had after seeing each of my children born.

For video of the first flight, click here:

Also read these related stories:

Melmoth 2: A Personal Airplane

Cleaning Up Melmoth

Five Years With Melmoth 2