Error Chain

Prop governor failure-everything was wonderful, right up until it suddenly wasn't.


Myron Nelson completed his RV-10 after seven years of solo building. (Photo: David Zickl)

After considerable fidgeting, I finally got the oxygen cannula situated to its least uncomfortable position. It’s funny how these cannulas often seem to feel askew when you don’t wear them often and first put them on. I took a selfie just to make sure it was correctly positioned.

Mere moments before the prop governor failed, Myron took this selfie to see if his cannula was positioned correctly.

Abeam the Bryce Canyon area, I had climbed our RV-10 to 11,500 feet to clear the eastern Grand Canyon Special Flight Rules Area (SFRA) as we continued our scenic flight south toward our Arizona home after a wonderful trip in and around Utah. I have made numerous trips over this route, and my personal safety preference (now limit) was to be south of the San Francisco Peaks north of Flagstaff before dark. In this moment we were timed perfectly, and we were just a few minutes away from a wondrous view of the Grand Canyon, which would sure to be highlighted by a brilliant sunset.

I reclined the seat back a bit and had a glorious and cathartic moment of reflection. One of the most beautiful parts of one of my favorite Eagles songs was caressing me through my headset. It was one of those magic moments you dream about during the years of sanding and riveting that are part of the build.

The airplane was performing marvelously. I reflected back on how just in recent weeks I had enjoyed a wonderful trip in Baja Mexico with the Flying Samaritans. A week later, my wife Evie and I had a terrific getaway on Catalina Island, even stopping in Chino, California, on the way back to scratch Flo’s Caf off of the bucket list. Now we were on the last leg of a fantastic trip to Utah visiting family and friends, and taking full advantage of the freedom of aircraft ownership as I had always dreamed that I would someday be able to do.

The previous day, I had the opportunity to take an old friend and his wife for a beautiful sunset tour around their mountain home in the Heber valley and even view where my wife and I had celebrated our honeymoon 35 years ago. I reflected in immense satisfaction on how the airplane had performed admirably and flawlessly on all of these recent trips. I made special note in my mind on how, after all of these recent trips, I was going to return home without a single squawk or complaint on the airplane.

The scenery was beautiful, the airplane was beautiful, my wife was beautiful. I’m very serious here. I even thought of deleting these few paragraphs as fluff, but the reflexive moment really did happen as I have attempted to describe. That sublime experience was the singular most rewarding moment in the pilot seat outside of the very first flight. It was nirvana right up until…uh-oh…it suddenly wasn’t.

What Was That?

Imagine flying at a high cruise speed, full cruise power, and someone reaches up and yanks your propeller control all the way back. That was the sudden sound and sensation that ruined my sublime moment. I’ve tried to imitate the experience in print, but there aren’t enough consonants available. It was an immediate change in sound and sensation concurrent with a strange, but obvious change in the thrust vector of the aircraft. Unfortunately for me at the time, I had no clue as to what had just happened, other than something was obviously wrong, and my wife was looking to me to tell her what it was. I only wished I knew.

The first actions were 40ish years of muscle memory. All the engine controls went forward, the fuel tank selector switched over, and the fuel pump switched on. Those actions made zero difference, so I turned the fuel pump back off in case of fire.

Thirty years of airline flying had drilled it in: Fly the airplane. Analyze the situation. Take appropriate action. Maintain situational awareness. The airplane was doing fine on autopilot but was losing speed with lower thrust, so I set in a lower altitude and dialed in a slow V/S (vertical speed) descent, still continuing, for now, to our destination.

I started a more detailed scan of the engine instruments. Fuel flow was higher than normal, but I had just pushed it full rich. I brought it back to normal cruise setting with no change other than the resumption of normal fuel flow. Manifold pressure was also normal. My eyes dropped down to the oil temp and oil pressure, and they were both in the green and normal (and deceiving me by telling me the truth, as I will later explain). I pushed the EFIS alert button and no alerts were active. At this point, a proper native Utahn would say, “What the frick?”

Tuba City, Arizona, might be a bit off the beaten path, but it was located perfectly when the RV-10’s prop governor failed.

Finally, I looked at the tachometer. My rpm was significantly below normal. It had dropped from the 2400 I had set to down about 1600. Hello, that’s odd, I thought. I started rotating the Vernier propeller control back and nothing changed. Then quickly, fore and aft to the limits, but nothing changed. I had lost control of my propeller—but wait a minute—isn’t it supposed to go to fine pitch when that happens? Oh well, that’s for later, I thought.

Decision Time

The engine was still running reasonably smooth with all indications in the green, but obviously something was still wrong, and I didn’t have normal thrust.

This may have been one of the most beautiful areas in the world to find ourselves, but certainly not in this particular situation. Ahead of me lay Flagstaff. Its positives were a good full-service airport and closer to home, countered by the negatives of high terrain and very ugly plan B’s between our position at the time and the Flagstaff airport on the other side of the high terrain.

Behind me was Page, with fewer services, especially on a weekend, but also hostile terrain separating our position and the Page runway. Ahead and to my right was Grand Canyon airport, a tad closer than Flag, but the direct route to that runway was over a great big ditch. Finally, to my left was Tuba City, which I knew had little to offer except a runway; however, I couldn’t dismiss the fact that it was the closest runway to our position at the time.

One more look at the (deceiving) oil instruments, and I briefly leaned towards continuing on to Flagstaff, as there was comfort in getting closer to home. Lastly, I glanced to my left and could actually see the Tuba City airport beacon. That was all I needed to seal a decision. I yanked off the oxygen gear that was now a distraction and turned my wounded baby toward TBC, knowing I could make it, even if we ended up dead stick for some reason. “Make a decision and then make the decision that you made the right decision,” a beloved mentor used to say. Airstrip with the highest chance of safe arrival, here we come.

Coming quickly upon an extended base entry to the runway at TBC, I was both high and hot, which I kind of expected with a slick airplane, a nearly feathered prop, and a space-shuttle approach. Energy management was a key and something rarely practiced in the GA world. I really did not want to go around with an ailing aircraft or go four-wheeling off the end of the runway. Conversely, I wanted enough energy in the bank to still make it if the engine quit. Convinced that I had it made, yet still a little high, slipping the aircraft for a bit got me back to a relatively stabilized, albeit steep, approach. Even though I fully expected it, the lack of propeller drag through final and into the flare was still remarkably noticeable. I hit the touchdown zone perhaps 15 knots hot, but the runway and brakes were sufficient for a normal low-stress rollout. When I got it stopped, it was a little awkward with the propeller situation and Van’s castering nosewheel design to make a 180-degree turn on the runway and taxi back to the tie down ramp. But with some body English on the brakes, while trying to use as little power as possible, we got it done.

The pool of oil on the ramp was the first clue the problem wasn’t going to be fixed in 20 minutes. In about 6-7 minutes of flight time, the RV-10 had lost nearly half its oil.

Looking for Clues

Upon shutdown, I knew Evie was going to have questions, but bless her heart, she just gave me a reassuring smile and a silent look of confidence. My first thought (hope) was that the control cable had merely become disconnected from the prop governor, and with a nut and bolt from my field kit, we’d be on our way in 20 minutes tops. Wrong.

I ambled out of the aircraft, hoping for the best, but my heart sank as I rounded the wing—in less than a couple of minutes of being stationary, we had already accumulated a saucer plate sized pool of oil on the ramp, with continuing drips and streams out of the outlet duct and bottom gills.

By the time I got the upper cowling off, it was getting dark and the abandoned ramp was very dimly lit. Evie dutifully held a flashlight while I poked around for a clue.

And then, there it was, staring right at us. The side casing of my propeller governor had been forcibly breached open, allowing high-pressure oil to spew out. The offending chunk of steel that caused the breach was still visibly wedged into the laceration of the sidewall case. Like most pilots often do when something goes awry, I had a momentary thought of relief—well, at least it wasn’t my fault.

The moment was brief, however, and then stark reality quickly set back in. No offense to the fine folks of Tuba City, but you can definitely see the middle of nowhere from their ramp. The only aircraft on the field was mine, and the only structure within the fence boundary was a green plastic porta-potty (that was padlocked).

Back when I was going through the rote steps of dealing with an in-flight abnormality, unbeknownst to me, my engine was suffering from an arterial bleed of precious oil even while those lying by telling the truth oil gauges showed steady in the green. I had left Salt Lake with over eight quarts of oil; I now had less than four. In about 6-7 minutes of flight time, most of it at idle, I had lost nearly half of my oil. And I wouldn’t have even known it was spewing until mere moments before the engine seized. At that moment, the adrenalin rush gave way to a stress crush. Continuing to Flagstaff, turning back toward Page, or going direct for Grand Canyon Airport would have certainly been a short-notice off-airport landing in very inhospitable conditions in near-nighttime conditions, the latter almost certainly fatal.

Now my mind was racing and the brain RVR was dropping. Why was I so calm and relaxed in the airplane and so flummoxed now? Relax, breathe, stay strong for Evie, I thought to myself, while feeling every heartbeat in my head. Luckily the dark moments passed quickly and I was able to regroup and start thinking about what to do next.

With its side casing forcibly breached open, the propeller governor allowed high-pressure oil to spew out.

Calling the Cavalry

One of the things I have learned about aviation in general, and the Experimental world in particular, is that the main draw of participation isn’t about flying machines. It’s about the people we are blessed to associate with, who share our passion and interest. The flying machines, wonderful that they are, are merely nuclei that bind our kind of people together.

For independently minded people like we aviators tend to be, it is an awfully humbling experience to be AOG (aircraft on ground) and in a position of needing to call on someone for help. However, by the same token, there is tremendous comfort in being a part of a very special fraternity that swarms to the assistance of those of us in need. After a few one-bar-of-service phone calls, we arrived at the last hotel room left in Tuba City, with at least the comfort that help (and a loaner prop governor) would be meeting us the next morning.

The following day, we barely had the cowlings off when two of the finest flying men I’ve ever met, Jim Wethington and Scott Williamson, both revered retired Southwest Airlines captains, arrived almost simultaneously—Jim by Toyota and Scott by Bearhawk. Between them, they had the loaner governor plus sufficient oil, hardware, tools, paper towels, knowledge, compassion, and humor to field repair our stricken carriage. While we worked on the plane, Evie took Jim’s car into town and got the rest of what we needed to complete the job at Taco Bell.

Once everything was back together and working properly, Jim drove back to his airpark home, about halfway between Tuba City and my home, and Scott flew loose formation escort with us back to the Phoenix area in his Bearhawk.

Upon safe arrival, and even knowing that there was still a long and uncertain road ahead, I breathed a heavy sigh of relief pushing our airplane back into its home-base hangar. Little did I know at the time that there had been at least four fellow aviators who had encountered a similar failure of the exact same component, the most recent being exactly one week previously.


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