The reduced throttle brought some relief to the vibration but not enough. I backed off the prop control and finally found a spot where the vibration didn’t threaten to tear the engine from its mount. At this power setting, the VSI showed we were losing altitude at less than 20 feet per minute as the altimeter hand almost imperceptibly unwound toward 400 feet msl. We were by then barely 200 feet above the treetops passing below.
With a quick scan over my shoulder I saw and heard Jerry calmly preparing the other four passengers for what he too expected would be an unscheduled meeting with Mother Earth. His military discipline was in full charge, which thankfully left me free to fly the airplane.
My mind was racing as I evaluated the options. I was in a stabilized slow descent, though, with no assurance it would continue. I didn’t have a clue as to what was wrong up front, but the oil pressure was steady and things weren’t getting any worse. The trees ahead were simply not a viable option for a forced landing, but there was a large cotton field 30 degrees and one-half mile to the right of our heading. I knew that I had to reach that cotton field to have a legitimate chance of any of us surviving the crash.
I gently banked the Cherokee to the right and was immediately met with an increasing rate of descent. I leveled the wings to preserve my altitude and nudged the right rudder. With each nudge of the rudder the nose moved a few degrees toward the cotton field with almost no increase in the rate of descent. The 30-second ride over the trees to the field felt like the longest hour of my life, but as the cotton plants passed beneath our wings, we were still holding 200 feet between us and the ground.
To the right of the field below us was another open field, and beyond that another, each of which would take us around in a big circle to the runway. With the luxury of plowed fields the entire way around, and no reason to choose one field over the other for a forced landing, I nudged the rudder and kept bringing the airplane in a circle back around to the airport.
It was probably a two-mile circuit back to the approach end of Runway 13. The trip seemed to take an eternity, but, with only one small patch of woods to cross right before the threshold, we made it. I cut the power over the numbers, made a silky-smooth landing and coasted to a stop just as the engine quit and the prop came to a silent halt.
We exited the airplane half laughing and half crying in amazement at our good fortune. I took the tow bar from the front baggage compartment, and we began pulling the airplane the half-mile to the hangar. Looking back, it’s funny that no one suggested going for the powered tug.
The next day, the local A&P called me to come out and see the damage. The Lycoming had swallowed a valve, which had embedded itself in the top of the piston as securely as if it had been welded there. The combination of the imbalance of the piston and the detonation within the open cylinder had set up a resonance of vibration that, well, you just had to experience to believe.
Today, the FAA training syllabus emphasizes the common human errors of aeronautical decision-making. My errors that day were multiple and compounded. I allowed myself to be pressured by circumstance to take some friends “around the field” knowing full well that the airplane would be at least 10 percent over gross weight in searing heat and humidity. An off-field “landing” was averted by the narrowest of margins. Had we been at the legal gross weight of the Cherokee, that margin would have significantly increased.
Of the five hazardous attitudes the FAA lists that negatively impact a pilot’s judgment, that day I was guilty in varying degrees of at least four: impulsivity, invulnerability, macho and resignation. Combined with the inevitable application of Murphy’s Law, it was a dangerous cocktail of poor decisions that almost cost six people their lives.