Never Again: Wild ride

January 1, 2008

The day dawned bright and clear, with beautiful Arizona desert winter sunshine and a brisk breeze. I had stopped for the night in Yuma, Arizona, on my way back to Van Nuys, California.

Refreshed by a good night’s sleep, I walked into the Yuma Flight Service Station, VFR flight plan in hand, ready for a pleasant two-hour trip home in a rented Cessna 150. The weather report mentioned a strong northeasterly wind, but there were no pilot reports of turbulence. My route of flight would be over and near mountains, but I reasoned that a cruising altitude of 8,500 feet would allow more than adequate terrain clearance, even with a strong wind. I filed the flight plan accordingly.

After some light turbulence during the climbout, the air became eerily smooth. But nearing El Centro, I began to experience strong updrafts and downdrafts. In the updrafts—at idle power with an indicated airspeed of 90 mph and the Cessna’s nose pointing down—the aircraft ascended 500 feet per minute. Conversely, in the downdrafts—at full power and best-rate-of-climb airspeed—the aircraft descended 500 feet per minute! This cycle repeated several times, but the ride remained extremely smooth and then the up- and downdrafts stopped.

Shortly after passing the Julian VOR, which is situated on a prominent peak, a strong and smooth downdraft took the aircraft down to 6,500 feet before I could maintain level flight. By then, I was just west of Lake Henshaw.

At this point an inexplicable thing happened to my thought process. Looking ahead, the terrain was much lower than it had been on the route so far, except for Mount Palomar, which was off to the northeast and to the right of my flight path, with its highest point near the famous observatory at 5,710 feet. Tired of the roller-coaster ride, I decided not to claw back up to 8,500 feet, even though I’d be passing the length of Mount Palomar only a few miles southwest of its long ridge, less than 1,500 feet higher than its peak, and on the downwind side on a day with a strong northeasterly flow. I wonder to this day how I could have suffered such an egregious lapse in judgment.

The turbulence generated by the mountain hit without warning and with all the subtlety of a sledgehammer. The little Cessna shuddered and groaned in a terrifying manner. “Slow the airplane down, but not too slow, easy on the elevator,” I silently repeated as the stall horn wailed and the airspeed and vertical speed indicators wildly fluctuated.

Something, probably my backpack, hit me on the back of the head. Loose objects on the seat next to me bounced so hard against the overhead I could hear the impact. At one point with the airplane nearly upside down, I remember glancing at the tawny-colored granite terrain scarcely 2,000 feet below and wondering what it would be like to flutter down to my end there in a structurally crippled 150.
Lucid judgment returned in a flash. What on earth was I doing in this place under these conditions? Finally, having more or less regained control of the airplane, I gingerly turned southwest directly away from the mountain. It took only 30 or 40 seconds to be out of the violent turbulence. Shaken, my heart in my throat, and a record level of adrenaline pumping through my body, I managed to call San Diego FSS with a request to warn others to stay clear of the area. I gave the mountain a wide berth before continuing on my route.

The remainder of the trip was uneventful. Still dazed, but safely on the ground at Van Nuys, I reported the incident to the flying club. I suggested the aircraft undergo a structural evaluation before the next flight. Then I personally inspected the 150’s exterior for any obvious damage. I found none, no bulges or wrinkles or anything loose, and gave silent thanks to the manufacturer’s airframe engineers. The only damage was to my personal belongings. It took nearly 20 minutes to find all the items, large and small, from my flight bag—charts, checklists, pencils, flashlight, and extra batteries. This search led to a sobering thought: What if one of those small items had lodged in a location that rendered a flight control component inoperative? I vowed to secure everything, including seatbelts, on every flight from then on.

This experience has taught me firsthand to be cautious about flying in the mountains when strong winds are reported—I won’t again ignore the potentially devastating consequences of flying on the mountain’s lee side on a windy day. What I experienced has a name—it’s called mountain wave. The smooth up-and-down action of the air at altitude was produced by a wave of airflow generated between stable layers of air over the mountains. The severe turbulence I encountered was a hallmark of the rotor that exists where the trough of the wave creates interference with the terrain below. It was such a traumatic experience that it has taken me several flights to overcome tensing up—even in light turbulence.

Ronald F. Brusha, AOPA 2847459, is an instrument- and multiengine-rated commercial pilot who has accumulated more than 2,300 flight hours during 39 years.

Never Again Online: Gear glitch

Your aircraft’s retractable gear malfunctions. What are your options? How would you cope? While you carefully ponder these questions, read this pilot’s account on the subject in this new Never Again Online story.

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