There used to be a Grumman Albatross — a 2,800 hp, 28,000-pound flying boat — at the airport where I keep my airplane. Its occasional takeoffs began with a growl echoing among the hangars and swelling to a smooth, leonine roar. I would gaze after the straining sound as it faded eastward. Nothing. I would always think, “There, finally, it’s happened; he put it down in the gravel pits.” And then at last the tip of the fin would appear, and the wing and finally the hull would rise slowly above the buildings in the middle distance. I never saw so much noise yield so little vertical motion.
Last week, when I was at the airport working on my airplane, I heard the sound of an airplane taking off and I turned to watch, as I always do, partly from curiosity and partly just in case. This time it was a Long-EZ that was taking off, and it was well above the trees and the hangars when I first saw it. But then its engine seemed to lose power, then regain it, then lose it again. The airplane was about 300 feet above the ground, I think, and not far past the departure end, when the pilot made the decision to turn back. He did a good job, banking steeply, keeping the nose down, rolling smoothly from a 230-degree right turn to a 50-degree left one. When he disappeared behind the hangars, it was evident that he would make the runway comfortably.
My first thought was that he was lucky to be flying one of those Rutan canards, because they won’t stall, and so the major danger of any turnback, a spin departure, was spared him. Also, he had some power; it was intermittent, but it never went away entirely. On the whole, it was a good thing to see — an emergency well and successfully disposed of.
It reminded me of something that happened to me many years ago, in the 1970s, also at this airport. I had made a couple of mufflers for my then airplane, the all-metal first Melmoth. They hung beneath the fuselage, each one a yard-long cylinder with a perforated inner liner, a packing of glass wool and an outer shell. Lengths of flexible stainless-steel ducting connected them to the exhaust pipes. They were made of aluminum, because someone whom I had confidence in had told me that the temperature of exhaust gas leaving the pipe is around 500 degrees. Of course, he had been thinking of an open pipe, not one with several feet of additional tubing downstream.
Whether because of the heat or the vibration or the force of the exhaust stream or all three in concert, I was about 200 feet in the air when I heard a muffled thud and the power fell off drastically. The engine did not sound good, and I was just able to maintain altitude at 90 knots. I knew enough not to try to turn back. The railroad tracks and power lines ahead of me did not look hospitable, and so I decided — not that I had much choice — to try to make it around the pattern.
I was in the middle of the downwind leg when smoke began rising from the cabin floor on the passenger’s side. On base, it filled the cockpit; it was becoming difficult to breathe and see as I turned final, touched down and opened the gull-wing door as I rolled off the runway.
Both mufflers had collapsed internally, completely blocking the exhaust. By luck, however, a circumferential crack had opened in one of the flexible ducts, and so the three cylinders on the right side of the engine continued to operate, though with greatly increased back pressure. The crack, as it happened, was on top of the pipe, and a narrow jet of exhaust gas, like a blowtorch flame, had melted its way through the cabin floor, which, for what I imagined at the time to be sound-deadening purposes, was a laminate of two aluminum sheets with dense foam rubber in between and a carpet on top. The smoke in the cockpit was from the burning rubber.
