Learning My Lessons
Once upon a time, we were all student pilots, struggling to learn the lessons in our training curriculum and obtain a certificate. Once we got that certificate, though, the learning didn't stop. As our confidence grew, we tried new things, learning by experience. AVweb contributor R. Scott Puddy went through the same process. Here's his story about lessons that combined an encounter with carbon monoxide poisoning and "get-there-itis."
The year was 1992 and my flying life was about to change forever — for the better. It could just as easily have ended.
I took my first flying lesson in the fall of 1978. It was a happy diversion from the life of a first-year law student. I was so enthralled that I bought Dad a flying lesson as a Christmas present. He fell for flying about as hard as I did. After a single lesson in a well-worn C-172, Dad put in an order for a factory-new Warrior. He picked up N2885B at Piper's Vero Beach facility in the spring of 1979 and (with more than a little help from his flight instructor) flew it home to Seattle.
Although flying was cheaper those days, I was an unemployed graduate student. The lessons cost around $30 each and I scheduled one whenever I looked into my wallet and found $30. My law school studies also interfered from time to time. Despite my somewhat haphazard training schedule, I was the proud holder of an FAA Private Pilot Certificate by the end of the school year. Dad likewise earned his license.
Over the next several years I finished law school, got married, took a job, and became a father, all of which diverted time and money away from flying. I had the privilege of flying N2885B during my occasional visits to the Pacific Northwest. Otherwise, I was a financially strapped renter pilot. During the twelve years that followed the issuance of my Private Pilot certificate, I logged a grand total of 178 hours, which included only three flights over three hours long.
It was Christmas 1991 when I received the fateful pronouncement from Seattle. Dad had racked up several hundred hours in N2885B and had earned his instrument rating. For safety's sake, he thought it essential that I should become instrument rated. His Christmas gift to me would be two months' use of N2885B to facilitate my training.
Wow. It was time to get serious about this flying stuff. I purchased my first-ever headset and, on March 8, 1992, I hopped a commercial flight to Seattle to pick up what would be (at least for a couple months) "my" plane. I couldn't stop beaming after Dad handed me the key. N2885B was fresh out of an annual and ready to go. This would be fantastic.
The flight from Seattle's Boeing Field (BFI) to Concord, Calif. (CCR), (5.4 hours with a fuel stop in Eugene, Ore.) would be the longest that I had ever attempted. The second leg of the flight started out at 11,500 MSL to clear the mountains southeast of Medford. It was cold and dark and I was running the heater off and on to keep my fingertips from turning blue. The new headset was giving me a headache. It spent as much time in my lap as on my head.
My discomfort increased steadily as time passed. By Red Bluff, about an hour and fifteen minutes from home, the pain was barely tolerable. In my rough-and-tumble formative years I had suffered the usual bumps and blows and had even suffered two concussions playing high school football. Never had my head pounded like this.
Throughout the final hour of the flight, I was fighting back tears. I was receiving flight following from Oakland Center and then Travis Approach. I did my best to retain my composure during my transmissions and thought I was doing an okay job of it. However, about 15 minutes from CCR, I lost radio communications with Travis. I tried at least half dozen times to raise the controller without success (I never did figure out why.) I keyed the mic on Travis's frequency and declared that I was switching to the CTAF for CCR. I announced my landing intentions over the CTAF and landed shortly before midnight at the desolate airport.
I held my head in my hands for about 45 minutes while I waited for a cab to arrive. My car was at Oakland airport, but it would have to wait there for me for at least another day. I had no intention of going anywhere but home.
The Plot Thickens
Within days, the memories of the agonizing flight were suppressed by my elation over having an airplane tied down ten minutes from my house and an airplane key in my pocket. I could fly whenever I wanted. No need to schedule a plane. No worries about returning on time. All I had to do was buy gas and oil, and N2885B didn't use much of either. I had big plans for that airplane.
I completed a dozen training flights during the next 30 days without any recurrence of headaches. On April 9, my CFII had me file a flight plan to Sacramento Executive (SAC) to practice ILS approaches. With my consent, another of his students was auditing my lesson from the rear seat. The usual routing to SAC was east then north via V108 and V6 at 3,000 MSL. This day, for some reason, we were assigned a radar vector to the north, directly over Travis AFB, at 5,000 feet, for the 20-minute flight to SAC.
We were leveling off and approaching Travis when our back seat passenger spotted trouble. "Look at the oil temp!" N2885B doesn't have cowl flaps and tends to run hot in a climb, but this instrument was pegged. The three of us stared at the dial for about five seconds without saying a word and then ... silence. The prop continued to spin but all the sounds that an engine makes when it is developing power abruptly ceased.
Following another pregnant pause, I suggested that we should run through the engine-out emergency checklist. That took about ten seconds. Still no noise from under the cowl.
If you were ever to have to choose a place to have an engine failure, our location would rank high on your list. Travis AFB has two military runways that support C-130s and KC-10s and the runways are staggered. We were looking straight down at some four miles of pavement dedicated to aviation use. We established the airplane's best-glide speed and reported our emergency to Travis Approach. The controller queried whether we could make the Nut Tree Airport (VCB) in Vacaville. Nut Tree is eight nautical miles to the north of Travis and has a single 3,800-foot runway. We advised that we would stay put and land at Travis.
As we circled in our descent, fear of injury was the furthest thing from my mind. The engine-out landing would be a piece of cake. I was much more concerned about the inconveniences that lay ahead. How would we get ourselves back home? How would I extricate N2885B from the hands of the military and get it up and running again so that I could complete my instrument training before having to return the plane?
Then, as abruptly as the silence had fallen, there suddenly was noise. We had touched nothing, but the engine inexplicably was once again running. We leveled off at about 3,000 feet and scanned the engine gauges. All readings were normal. We advised Travis that we would circle over the field while we assessed our situation.
After several minutes, all indications were that the engine intended to run indefinitely. From our location at or about the procedure turn for the LDA approach into CCR, we devised a plan to return home. A body of water was between us and CCR, so we climbed back to 5,000 feet while remaining over Travis. At that altitude, we would never be more than power-off gliding distance from a safe landing area. After the three of us concurred that the return was safe and prudent, we announced our intentions to Travis and turned toward CCR.
...And Some Insights
The remainder of the flight was uneventful. We stayed at 5,000 feet until we were practically over Concord and then circled down for a landing on the longest of the four runways. News of our situation had preceded us: Three emergency vehicles greeted us when we landed and provided an escort to the FBO. Almost instantly, there were a half dozen mechanics peering under and around the cowl in search of clues.
The problem was not difficult to identify. The carburetor for the Lycoming O-320 engine sits front-and-center under the engine ahead of the oil pan. It was discolored in the ashen hue of an overheated barbecue grill. A few inches in front of the carburetor sits the heater muff, a sheet-metal shroud that encircles the exhaust manifold and collects warm air for cabin heat and carburetor heat. Directly in line with the carburetor, the heater muff sported a one-inch by two-inch oblong hole that had been burned by the torch-hot exhaust gases escaping from a breach in the enclosed exhaust manifold. Next in the torch's path was the carburetor and the avgas therein. Suddenly, I felt nauseous.
Only then did I realize that I had narrowly skirted death twice in 30 days. My failure to detect that I was being poisoned by carbon monoxide during the cross-country flight was perhaps understandable. The effect of CO is to impede your mental processes. That is what makes carbon monoxide poisoning so insidious.
There are several lessons to be learned from this episode. The first is that my failure to follow up after the fact was a product of denial. I only had use of the plane for a few weeks and had scheduled a continuous stream of training flights for the entire period. There was no time in the schedule for the plane to be down for maintenance. Besides, it had just come out of annual. Therefore, there was no problem with the plane. Had I reflected at all on the possible causes of my symptoms, or discussed them with a more experienced pilot or my CFII, the possibility of an exhaust leak would certainly have been considered. A CO detector would have confirmed the problem and the incident over Travis would never have occurred.
The flight to and from Travis yields another lesson. A pilot's capability to assess and manage risks in an emergency is only as good as the available information concerning the specific cause of the problem. The engine had quit and then restarted on its own and we had no idea why. We never felt at risk because we assured ourselves that we would continuously be in a position to land. We had no idea that the O-320 was attempting suicide by immolation. We were considering only the risk of a power loss, not the risk of an engine fire.
A third lesson is that "just out of annual" doesn't tell you much about an aircraft's mechanical condition. The accident record is replete with instances of aircraft crashing right after having some maintenance performed. Whether the IA missed the hole in the exhaust or if it developed on the flight down from BFI, we'll never know. A more thorough pre-flight inspection would have found the problem.
...And Their Morals
The moral to lesson number one is that "get-there-itis" does not occur solely in connection with a single flight. It can infect an entire series of flights. The answer is the same. The desire to reach a destination or a goal cannot be permitted to overcome safety considerations.
The moral to lesson number two is that you have to identify what you do not know in order to assess and manage risks. If there are any unexplained facts, you have to presume the worst-case scenario. That just might be the situation you are in. The answer is usually to get the plane on the ground as soon as possible so you can determine what is really going on.
The moral to lesson number three is, to paraphrase Ronald Reagan, "Trust, but verify." While the exhaust leak was not in an area normally examined during a pre-flight inspection, it was relatively easy to spot. While marvelous in their reliability, general aviation aircraft are complicated machines with a lot of things that can gradually go wrong. Something more than a cursory walk-around is necessary every now and then, between regularly-scheduled maintenance.
To learn more about the insidious nature of carbon monoxide poisoning and what you can do about it, be sure to read AVweb Editor-in-Chief Mike Busch's review of electronic CO detectors.