It was late on a bright August afternoon, and I was flying VFR westbound from my home airport in Ottawa, Ontario, Canada, in my V-tail Bonanza at 10,500 feet in clear blue skies. On the horizon ahead, I could see scattered cumulus clouds typical of daytime heating. The bases were at around 6,000 feet, with tops well above 10,000 feet. Because the clouds were scattered and miles apart, I thought it would be a cinch to fly between these fluffy buildups.
One odd cloud appeared to be darker than the others, and it became obvious that it was producing rain and maturing into a thunderhead. I altered course about 10 degrees to make certain that I kept well away from the darker, more menacing clouds.
Up to the point where I reached the edge of the first line of cumulus and proceeded to fly between them—keeping my eyes on the distant horizon, which was clear and sunny—the flight had been as smooth as silk. As I began to pass by the clouds that were now well off both wing tips, the aircraft danced on gentle updrafts and downdrafts. There was no need, just yet, to reduce speed. The outside air temperature was 38 degrees Fahrenheit. Then raindrops appeared on the windshield. It began to rain harder as I approached the midway point of clearing the first line of clouds. Suddenly, as if I was on an elevator, the aircraft began to rise rapidly. The vertical speed indicator pointed straight up. I reached for the throttle to reduce engine power and pointed the nose slightly downward to return to my cruising altitude. (I say slightly because the Bonanza picks up speed quickly; redline speed can be reached easily in a matter of seconds.)
Then something happened that had never occurred before in my 40 years and 10,000 hours of commercial flying. The rain on the windshield turned to solid ice because the updraft had carried the aircraft above the freezing level. At the same time the pitot tube froze and the airspeed needle dropped to zero (this Bonanza did not have pitot heat). I could not see where I was heading, and I had not the slightest idea what the aircraft was doing speedwise.
I immediately reduced the throttle to idle. A few seconds later, when I felt that the speed had slowed to 100 miles per hour (the gear-down speed), I dropped the gear to increase drag because I didn't want to gain altitude and didn't want my speed to build up. I was also in a hurry to get back down to warmer altitudes.
I instinctively did what I had told my students to do during my years of instructing—do a 180-degree turn to return to the good weather from whence you came. Even at idle speed, the engine-driven vacuum pump was maintaining more than four inches of suction, and so the artificial horizon indicator and directional gyro were still functioning, enabling me to do a one-eighty on the gauges. Without an airspeed indicator under such conditions, the natural reaction is to do a shallow turn to be sure not to stall the aircraft in a turn at an obviously slow airspeed (idle engine and gear down). But with the windshield iced over, I could not know that my shallow turn now took me right into the middle of the cloud that I had tried so hard to avoid.
It became as dark as night. And there was lightning. I swore that someone was shooting at me with a machine gun, the noise was so loud. With the engine fully at idle, the hail that was bouncing off the all-aluminum aircraft made an ungodly din.
All the while I kept my eyes on the artificial horizon indicator to keep the wings level, and when the adjacent directional gyro turned to 090 degrees, I held it there. Three or four times the horizontal bars in the attitude indicator went from top to bottom and back again, which showed that the aircraft was gently stalling. The nose was rising and falling. The aircraft stalled repeatedly as if on a shallow roller coaster.
I still had aileron control, and I was pleased with the indication that I was flying near the stall because it meant that the airframe was far from being overstressed. The stalling was obviously due to ice on the wings, but also I was purposely flying at a slow airspeed. I was keenly aware that most fatal accidents in thunderstorms occur when the pilot loses control of the aircraft and makes such abrupt movements on the controls at high speed that the wings come off. I was determined that such insanity would not happen to me.
Then the fun was all over. I broke out at about 6,000 feet near Bancroft, Canada. There was a big slurping sound as the warmer air thawed the pitot system, and the airspeed needle showed that I was descending at about 70 mph. I did a 180-degree turn again and this time proceeded on my original course—but at 4,500 feet—in the rough air one can usually expect when flying below clouds on hot August days.
I was lucky because I had lots of altitude. But my experience made me think of two pilots who were killed in Ottawa a couple of years earlier. They were flying not too far above the peaks in the northern Appalachian Mountains. I learned that they were flying in near-freezing temperatures and that it was raining on the ground at the time of their accident. Did they, like me, also get sucked up several hundred feet into below-freezing temperatures and, with the windshield iced over, try to make a descending 180-degree turn—and with no visibility through the iced windshield did not realize that a hilltop lay directly in their flight path?
Lesson learned. Thousands of responsible VFR pilots try to obey the good airmanship rules. When they encounter weather conditions that are below VFR minimums, they do a 180-degree turn. That is what I attempted to do in this case. I had no warning whatsoever that there was any rain ahead of me. It was certainly not visible (meteorologists say that this is because on many days it may be raining at altitude, but the rain evaporates before hitting the ground). As I proceeded to pass between the towering clouds, I had a clear sunny horizon ahead, with visibility of more than 50 miles. It was legal VFR all the way. I also could not have predicted that I would encounter an updraft that would take me above the freezing level in a matter of seconds and turn the rain into ice.
I hope that this account of my experience will help other pilots to be more wary of innocent-looking maturing clouds on those hot summer days when thermal activity is pronounced and the moisture-laden air is so unstable.
Bill Peppler is the International Council of Aircraft Owner and Pilot Associations representative to the International Civil Aviation Organization (ICAO). He is a 10,000-hour pilot and owns a Beech Bonanza and a Cessna 150. He lives in Ottawa, Ontario, Canada.
"Never Again" is presented to enhance safety by providing a forum for pilots to learn from the experiences of others. Manuscripts should be typewritten, double-spaced, and sent to: Editor, AOPA Pilot , 421 Aviation Way, Frederick, Maryland 21701.
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