/ aviation

Sputter

After a promising fall season, wherein I shamelessly gushed about aircraft ownership and looked forward to the months ahead, I was greeted by a particularly pissed off Old Man Winter. This curtailed all flying for months. In fact, my flying has suffered a bit of a crimp even these last few months, as my weblog content clearly shows. Lately, I haven’t seen an aviation article on this site at all, just a lot of bitching and ranting.

Well, these last several weeks have allowed at least a bi-weekly foray onto the skies, and as we set the clocks ahead and the temperatures have climbed in fits and starts, I felt that soon I would resemble a pilot again. Every couple weeks or so, the weather gods acquiesce and grant me a weekend day suitable for a rusty pilot to take to the air, and I’ve been going up and attempting to gain confidence and sharpen my skills.

But every other flight or so, niner three foxtrot decides to throw me a scare.

This started way back at the beginning of our relationship, the first episode happening when I was getting checked out in her with my friend who helped me buy this plane. It seems that every once in a while niner three fox likes to start sputtering and dropping RPMs; the Continental O-200 engine alternates between a steady and confidence-inspiring WHAAAAAA, and a more attention-getting nnnnn, or even a dugga-dugga-dugga. This pitch/tempo change has also had the annoying tendency to happen shortly after takeoff, when we’re both rather close to the ground.

My friend & I have discussed this phenomenon a few times now. Since he was with me the first time this happened, I had the benefit of his experience in identifying the problem. He feels it was water ingestion—water mixing with the fuel/air mixture spraying into the carburetor. Remember the last time you had water go down the wrong pipe? You coughed and sputtered. That’s why planes have drains on each gas tank and other strategic locations along the fuel system, so the pilot can drain out the heavier water that can sometimes accumulate in the fuel system before each flight.

At first, the thought was that I didn’t drain enough fuel, or that the plane wasn’t quite level when I did so, so water in the gas tank was escaping detection during the preflight inspection. So, I have since tried to be ever more diligent in my fuel sampling. But “it” kept happening. Sometimes “it” would be a brief cough, sometimes it would be prolonged. Back around Christmastime “it” happened for so long that it actually scared the crap out of me. And the thing that pissed me off was, I was on my way to deliver a well-earned case of Molson Ice to my friend (his taste, not mine).

I was just a few hundred feet above the ground, having taken off after getting fuel—and yes, I checked the fuel I just put in—and the engine said: “WHAAAAA-nnnnnn-AAAAA-dugga-dugga-dugga-AAAA-nnnn”. I did not like this, what the engine was saying to me. So I kept climbing, and stayed within gliding distance of the airport. After leveling off at 2,000 feet, I circled around for a while, listening carefully. Niner three fox sung a sweet, steady song. So, I climbed up a bit higher and headed west to my friend’s airport, my buttcheeks firmly clenched.

The flight ensued without incident, and the beer was delivered. But we talked about the latest occurrence of “it”[tm] and my friend pored over niner three fox. His theory, besides that I simply wasn’t dilligent enough about draining fair samples from the tanks, was that water was collecting in a bend in a SCAT tube by the engine air inlet. His theory is that the water pools there after a rainstorm, and sits there idly by while I taxi and start my takeoff roll, but shortly after I pitch the plane up to climb away from the earth, that water flows back into the carburetor and causes “it”[tm] to happen. The solution was to plug the opening to the SCAT tube while the plane is parked, which I did with a rag for a few weeks and then got fancy cowl plugs to do the same thing later. The next few flights ensued without incident, and I considered my friend’s advice to be the solution to the problem.

Today I learned we have not quite solved it yet.

After an uncharacteristically early awakening sans-alarm clock, and a decent weather briefing, I scooted to the airport this morning in hopes I could get in some airtime before the winds kicked up and the rains followed this evening. A leisurely preflight ensued, and then niner three fox started up easily. After a run-up check we were ready to go.

“Central Jersey traffic, Cessna’s departing runway two-five…” WAAAAAA… “Central Jersey traffic, Cessna’s departing the pattern to the west” ...nnnnn…sputter…dugga-dugga…nnnn…dugga-dugga-dugga.

Assuming this was the same water problem, I pitched forward and leveled off, and the engine eventually smoothed out. But I had no interest in leaving the general vicinity of the airport now, at 600 feet above ground level. I began a very shallow climb, which went well. Then to test my friend’s theory I went full power and pitched up again, and “it”[tm] happened again. So, a slow climb to 2,000 feet, and: “uh, Central Jersey, the Cessna just off is gonna cross midfield at two thousand, rough engine, gonna loiter east of the field.”

The runway slid underneath, looking like Linus’ security blanket. I climbed to 2,500’ and circled around for a spell, and of course in level flight niner three fox ran like a top. But I figured that since my plane is due for an annual inspection and some other work, I’d just head back and wait for my friend to have a look at her.

And here’s what really pissed me off. For the next five minutes, both plane and pilot performed flawlessly.

Still concerned about the rough-running engine, I wanted to stay as high as possible for the duration of the flight, but you really need to be at pattern altitude—generally one thousand above ground level—by the time you arrive at the traffic pattern. So I chopped the throttle, applied carb heat, and started spiraling down, keeping the airport in sight. After two 360s, I was at 1800’ and set up on a perfect 45 degree line for the downwind leg. I announced my approach. I hit pattern altitude about a quarter mile from the downwind leg, and slid right into the pattern. My approach was tighter than normal, again a nod to the idea that the engine may get annoyed at keeping us in the air and go on strike. The view on final approach was unusual, but I realized it was because it was the view I’m supposed to have all the time. My speed was dead on, the descent angle perfect, and the landing, oh lets talk about the landing:

Perfect. Just past the numbers, the main wheels started rolling, because they had just come in slight contact with the runway surface. The only clue that this thing that belongs in the air was now a ground vehicle was a slight vibration in the seat of my pants. I raised the flaps, leaned the mixture and shut off the carb heat all while holding the nosegear off the runway as long as possible. I coasted off the runway at the first turnoff, and listened to the engine purr.

I debated taking off again, to experience that kind of perfect flight one more time. I realized that not only is my engine being balky, there’s no way my next approach & landing would be anywhere as perfect. I chalked up the whole experience to another reason I love aviation: moments of excitement, beauty, satisfaction, uncertainty, and fun.

For example, as I flew around there near my airport, I managed to steal a few glances at the amazing view; from only 2,000 feet I could see Philadelphia and New York City simulataneously.