I just returned from a 5,300-nm cross-country flight in my Cessna 310.
I love trips like this. It’s one thing to FLY an airplane for fun or sport, and quite another to USE an airplane as a serious traveling machine. I’ve always been a USER, and typically fly at least one transcontinental trip per year, and sometimes two or three.
This was the first of three such trips that my partner Nona and I had planned for 2018. Our itinerary first took us from our home base in California to West Virginia to attend and speak at the Flying Physician’s Association annual meeting at The Greenbrier in White Sulphur Spings, West Virginia. Next stop was Rhode Island, where we spent a lovely week of sightseeing in the beautiful Ocean State. Then we headed westward to Montana, where I met up with my colleague Paul New to teach an all-day owner maintenance course at the AOPA Regional Fly-In in Missoula, Montana. Finally, after two-and-a-half weeks on the road, we returned home flying a somewhat circuitous route via Medford, Oregon, to avoid an area of convective weather developing in Nevada. What a fabulous trip.
This was Nona’s first long cross-country via GA. Most of her previous flights with me lasted an hour or two at the most. She was predictably a bit apprehensive about making a trip of this magnitude in a small plane, so I decided to plan the trip in a way that would hopefully minimize her stress level and physiological discomfort. I vowed to break up the trip into legs of no more than three hours duration (instead of the four- and five-hour legs I often fly when I’m solo), and to choose a route where the minimum IFR altitudes were no higher than 13,000 feet so Nona wouldn’t have to deal with supplemental oxygen (instead of crossing the Rockies in the low Flight Levels as I often do when I’m solo).
We decided to start off flying to Wichita, Kansas, and remain there overnight before continuing eastward. Although I’ve occasionally made it nonstop to Wichita from my home base—the plane carries six hours of fuel—I decided for Nona’s sake to stop for lunch, fuel and restrooms about halfway to Wichita in Show Low, Arizona. Here’s a bit of interesting trivia…
According to legend, the city’s unusual name resulted from a marathon poker game between Corydon E. Cooley and Marion Clark. The two men were equal partners in a 100,000-acre ranch; however, the partners determined that there was not enough room for both of them in their settlement, and agreed to settle the issue over a game of “Seven Up” (with the winner taking the ranch and the loser leaving). After the game seemed to have no winner in sight, Clark said, “If you can show low, you win.” In response, Cooley turned up the deuce of clubs (the lowest possible card) and replied, “Show low it is.” As a tribute to the legend, Show Low’s main street is named “Deuce of Clubs” in remembrance. —Wikipedia
What Are The Odds?
About two hours into the three-hour flight to Show Low, I heard Nona asking me over the plane’s intercom, “What this?” I glanced over and saw her pointing at the vacuum gauge on the extreme righthand edge of the instrument panel. One of the two red balls had popped out, signifying that one of the airplane’s vacuum pumps had failed. The other pump was working fine, and the vacuum reading remained at 5 in. hg., right in the middle of the green arc.
I explained this to Nona, quickly adding that there was nothing to worry about because the airplane has dual vacuum pumps—one mounted to each engine—so the loss of one vacuum pump was only a minor annoyance, and something I’d experienced quite a few times during the 31 years I’d owned the Cessna 310. I further explained that because these vacuum pumps always seem to fail during long trips, I always carry a spare pump in my wing locker, together with all the tools necessary to remove the failed pump and install the spare. I figured we’d do this at some convenient point during the trip, perhaps during our vacation week in Rhode Island.
Nona seemed slightly shaken by the pump failure but reassured by my explanation. Fifteen minutes passed. The GPS showed us less than 30 minutes out from SOW. Then Nona called my name over the intercom and once again pointed to the vacuum gauge. I looked at the gauge. Now both red balls were popped out and the needle read zero. I’d experienced a double vacuum pump failure!
What are the odds? I’d never before experienced the loss of both vacuum pumps during one trip, much less one leg. I believed the odds of this happening were close to infinitesimal. But it happened. Apparently, the Laws of Probability had been trumped by Murphy’s Law.
Truth and Consequences
I quickly sized up the situation. With no vacuum, the vacuum-driven attitude gyro would quickly spin down, roll over, and play dead. The attitude-based 400B autopilot would dutifully follow the dying attitude gyro and put the airplane into a graveyard spiral unless I disengaged the autopilot and hand-flew the airplane—which I promptly did. No big deal, since Show Low was now just minutes away and the weather was typical for Arizona: severe clear and windy.
However, the consequences for the rest of the trip were dire. My personal minimums say that a non-functioning autopilot is a no-go item for flights exceeding one hour. Furthermore, I was flying a VFR-only airplane on a trip where significant instrument weather was forecast in the eastern half of the country. Continuing the trip without pneumatics was infeasible. But canceling the trip was unthinkable. So clearly, I was going to have to replace one of the failed pumps at Show Low before launching for Wichita and points east.
The landing at SOW was turbulent. The surface winds were gusting to 25 knots. We parked the airplane close to the fuel trucks, went inside to place a fuel order, eat some lunch, and use the facilities (not necessarily in that order).
I asked the fueler if there was a maintenance shop on the field. He said no. I asked if there was some kind of maintenance hangar I could use for an hour or two. He said there wasn’t. I quickly concluded that I’d have to replace the pump myself on the tarmac in a howling 25-knot wind. Are we having fun yet?
I asked Nona if she was willing to help me, and warned that she would probably get her hands dirty. She was game. I pulled my traveling toolkit out of my wing locker and borrowed a small stepladder from the fueler. Nona and I gingerly removed the top cowling of the left engine, making sure the wind wouldn’t catch it and wrest it from our grasp. We carefully set the cowling on the tarmac under the wing, hoping it would stay put while we worked on the pump.
The pump transplant itself took us about three hours, twice as long as normal. We were working under battlefield conditions, the wind whistling in our faces, the sun in our eyes. Finally, with the sun low in the southwestern sky, we finished the job, secured the cowling, and started the left engine for the “smoke test” of the newly installed pump. It worked. The left red ball was sucked in, the vacuum gauge needle moved to the middle of the green, and the attitude gyro erected normally. We were back in business, albeit one pump shy of a full load. It was enough.
I couldn’t help but think how lucky I was. I was an A&P. I carried a spare pump. I had all the necessary tools to install it. Had any of those three things not been true, I’d have been in a real pickle and the whole trip might have been in serious jeopardy.
We took off for Wichita nearly four hours behind schedule. As a result, what was planned as a daytime flight wound up being a nighttime flight. That spooked Nona a little, as she’d never flown at night before, and much of the flight was over desolate terrain with very few lights to provide a visual reference. She was very relieved when we touched down at Wichita’s Dwight D. Eisenhower National Airport, were marshalled into the Signature Flight Support ramp, and quickly whisked to the DoubleTree by Hilton on the airport.
First thing the next morning, I went online and ordered two vacuum pumps from Aircraft Spruce, to be shipped from their Atlanta warehouse to The Greenbrier. One pump would be used to replace the still-failed pump on the right engine, while the other would become my new spare.
We flew our next three-hour leg to Lexington, Kentucky, in IMC conditions, rented a car, toured around the beautiful bluegrass horse country, and stayed overnight. The next morning we made the short but seriously IMC flight to Greenbrier Valley Airport. The vacuum pumps from Aircraft Spruce arrived during our Greenbrier stay. We considered installing one of the pumps on the right engine before departing West Virginia, but ultimately decided to defer that until we got to Rhode Island.
Nona and I also performed the second pump transplant on the tarmac at Quonset State Airport, but there wasn’t much wind and we got the job done in about one hour flat. Nona proved to be a terrific mechanic’s helper, handing me exactly the right part in exactly the right order like a top-notch surgical nurse.
The remainder of the trip to Montana and California went off without a hitch. After returning home, I researched my maintenance logs to find out when the previous vacuum pumps were installed and how long they lasted before failing. Turns out the left pump lasted for 8 years and 700 hours, while the right pump lasted for 9 years and 800 hours.
What were the chances they’d fail within 15 minutes of one another? Obviously greater than I thought. Hmmm…