It was 11 years ago this September, and the weather at the Chester (Connecticut) Airport was beautiful — a typical late summer morning, complete with a bright sun rising over the lazy fog on the Connecticut River. The preflight inspection and runup of our 1966 Alon Aircoupe were completed for what was to be a short flight to New Haven for my wife and me.
On takeoff, the power came readily up to full. We lifted off, and the altimeter began winding up — 50 feet, 75 feet ... then silence. The engine quit.
If you have ever flown out of Chester Airport, you probably recall that it is surrounded by trees. It is built on a ridge that runs north to south and, at the time of the incident, had a runway approximately 2,600 feet long. (It has since been improved and extended.)
There was no convenient place to land an airplane in trouble. We were already past the halfway point on the runway, which left us no chance to get safely back down on the pavement.
When the engine went quiet, I pushed the nose down to level attitude and pulled back about halfway on the throttle knob. The engine suddenly came back to life with a burst of power. But before I could sense any relief, it quit again. The engine began to develop a cycle — three seconds of power, three seconds off — like a World War I-era rotary engine on approach.
The lowest point in the tree line was an area off to the left side of the runway where some trees had been removed to provide a site for a small factory. I headed that way, hoping that it might give a few additional seconds to think about what to do before we descended into the waiting trees. Luckily, the ridge upon which the airport had been built provided sloping hillsides in nearly all directions. We found ourselves burping along on these bursts of power, on the edge of a stall while gradually losing altitude.
Cedar Lake was about a half mile away, and we might have been able to reach it; but I don't swim. I began to search for a small field that I had seen before from the ground. I finally located it, but it was tiny and had a huge tree in the middle of it. All of the local roadways were too narrow and were lined with overhanging trees. Out of desperation, I asked my wife where the runway was. She pointed in the direction of the right wing tip. The shocker was that we were level with the runway. With the engine burping along, I didn't dare risk changing the throttle setting or applying carburetor heat, for fear that the engine would quit altogether.
Somehow, some way, that little airplane, at gross weight and developing some unknown partial power figure, was lifted up over the trees and completed the turn to the airport.
The next thing I recall is that we were dragging the landing gear through the trees as we approached the runway at an angle. The airplane dropped the remaining six feet to the edge of the airport. We landed on the mowed area alongside the trees and rebounded into the air almost as high as the six-foot drop. A few more sickening, bone-jarring bounces and we were sitting on the edge of the airport, in one piece, with the engine merrily ticking over, as though nothing had happened. I was in a state of shock over what had happened in the space of about a minute and a half.
My first reaction was disbelief. How could this have happened? Did I neglect to do something during the preflight — did I overlook a step in my mental checklist that might have become boringly routine? No, I reasoned; we had flown so many years from this airport on the same kind of trip, with the same type of preparations, that there must be some as yet undiscovered explanation for this terrifying incident.
We taxied back to our tiedown spot and shut down. As soon as we had climbed out, somewhat shakily, I was on the telephone to a mechanic, to see if he could help solve the mystery.
Together we checked everything imaginable — fuel tanks, lines, pump, float setting, fuel flow — until we ran out of things to check. After this exhaustive session, the mechanic was convinced that it had been carburetor ice. I was having trouble accepting this because the outside air temperature was about 70 degrees Farenheit. How could the engine have made that much ice in that short time? The more I argued, the more convinced the mechanic became, on the basis that everything we could think of had been checked and nothing had been found amiss. His theory also included the fact that the humidity was quite high — remember the fog on the nearby river? Sure enough, after a test flight later that day, all was normal with the airplane.
The mechanic researched the carburetor ice problem and provided me with reams of information and the results of many studies. I was amazed to learn that carb ice can form in temperatures as high as 92 degrees Farenheit, as long as the humidity is greater than 50 percent. And I had always held the belief that it formed at or slightly above freezing. This is one case in which what you don't know really can kill you.
Bud Chappell, AOPA 324113, is a retired Connecticut public transit inspector who holds a commercial pilot certificate. He still owns his Alon Aircoupe.
"Never Again" is presented to enhance safety by providing a forum for pilots to learn from others' experiences. Manuscripts should be typewritten, double-spaced, and sent to: Editor, AOPA Pilot, 421 Aviation Way, Frederick, Maryland 21701.
