Severe turbulence on a clear day…or what my glider rating should have taught me.
I fly a Cessna 340 mostly for business on the West Coast. The weather in southern California was fairly typical on this early June day, with fog along the coast and clear inland.
I hadnt flown for several weeks, so I thought I would fly up to Tehachapi from my home base of Palomar Airport near San Diego for my $400 hamburger. The instrument departure was uneventful as I canceled IFR and continued on the 35 minute flight VFR with flight following.
The air was smooth at 12,500 feet, even though the winds were reported at 25-30 knots almost directly on the nose. I started my descent for Tehachapi and only encountered light chop on the descent until I was within 4 miles of the airport.
I picked up a bit more turbulence on the approach to runway 29 but the landing was uneventful as the wind was almost directly down the runway. To my dismay there wasnt a hamburger to be found at Tehachapi Municipal Airport, so I took off again and headed for Mohave which is only a 10-minute flight to the east.
Being a glider-rated pilot, I should have known that when there is a glider port in the neighborhood (and there is a big one in Tehachapi) there probably is a good reason for it – like great mountain waves from time to time. This was one of those times. As I headed east I flew over the ridge and saw the power generating windmills there going max speed, I encountered a moderate updraft followed by the most severe turbulence I have ever experienced in my 23 years of flying.
My headphones flew off my head, while charts and other loose objects went flying around the cabin. The aircraft had momentarily been totally out of control. I was lucky enough to have been below maneuvering speed, so I wasnt so concerned with structural damage but I immediately departed the area. The Mohave burgers would have to wait.
All of the signs were there for me to recognize the potential threat, but I had ignored all of them. First there was a glider port, second a strong and consistent wind flowing down over the Sierra Nevada mountains, and third there were 500 spinning windmills going max speed.
How much more warning did I need? Sometimes beautiful skies and unlimited visibility can lull one into a false sense of security to think there are no gremlins in our path.
Mountain waves can be a killer to almost any aircraft, especially general aviation aircraft. I learned to take nothing for granted on this spritely spring day.
Had it been a dark and stormy night, I would not be relating this story. In retrospect the weather report provided several clues that what I was about to make was a questionable flight. The dewpoint and temperature were two degrees apart. But the skies were clear, so a gloomy weather report didnt really make much sense. Besides, Id flown this route dozens of times.
My friend and I launched for a local night flight for dinner, with the skies hazy but no clouds. We landed and had dinner and when we returned to the aircraft I noticed an unusual amount of dew on the plane. The sky was still clear, and a crescent moon hung in the western sky.
We took off for the return trip with the ground lights clearly visible. The first sign of trouble came when I leveled off for cruise flight. I did not recognize the ground lights.
I decided I was too far north of my intended track, so I made a hard left to the south until I found my familiar ground check, then I turned west to continue.
Again, the ground lights started to look unfamiliar. The hills and freeway I was expecting to cross never materialized. I shot a VOR to a nearby airport to get my bearings.
I was still uncomfortable with my position, and now the ground lights had disappeared under a cloud deck. I was in VMC above a solid overcast. I called Flight Watch and explained my predicament. I wanted vectors to my home field – or any VFR field. They gave me to SoCal approach and I contacted them.
SoCal issued a transponder code of 7700 and vectored me to my home field. A few minutes passed and SoCal advised me I was four miles east of my home field. I told them that I still did not have ground lights in sight.
Shortly afterward, SoCal called again to tell me that I was now directly over the airport. The weather gods must have decided they had had enough fun with me, because almost on cue the cloud deck parted over the runway. I informed SoCal that I had the runway in sight and requested permission to descend for landing.
They granted my request, and asked that I call them after landing. I did so with a truly heartfelt thank you. My home field never looked so good. Every flight should be a learning experience, but as it turns out some teach more than others.
Its a comfort to know that my training was valuable, and when called upon, pulled me through. I remembered the 4 Cs: climb, conserve, communicate and comply.
Stay calm and fly the plane and talk to someone. You are not alone.
Walk First, Fly Later
I can remember three times when a final walk-around before entering the cockpit to go flying would have prevented episodes that were personal embarrassments but could have been much more.
The first was during a rain shower. I had done the preflight inspection while awaiting a passenger, but elected to leave the pitot cover on due to the rain and the plague of spiders that had descended on the airport. The pitot tube was on the opposite side of the cabin from the door and under the wing.
When the passenger arrived, we ran to the plane through the deluge and clambered aboard. It was fortunate that the wind was blowing from behind the airplane because after engine start I noticed the tip of the red flag on the pitot cover as it momentarily blew up into view.
I shut the engine down and removed the cover to avoid the surprise of no airspeed indication on the takeoff roll.
The second time was after self-refueling. I made it a point to always attach the static line to the wing tiedown ring before fueling and, on this particular occasion, forgot to remove it afterwards. The ring was on the opposite side as the entrance door.
The startup and taxi back to the hangar seemed normal enough, but after I got out I discovered the static line attachment clamp hanging from the tie-down ring. Fortunately I had not taken part of the static line with me, as that may have resulted in prop entanglement or wing damage if Id gone flying.
The third time happened when boarding a passenger who, again, arrived after the preflight had been finished.
Id left a wheel chock in place since the airplane would be sitting on the ramp unmanned briefly. When the passenger arrived, we climbed aboard, lit the fire and started to taxi, only to have to shut down and climb out to remove the chock.
All of these errors could have led to a damaged airplane, but I was lucky that I got away with only red cheeks. A final walk-around before getting into the airplane would have caught these errors.