A Dead-Stick Landing at Bozeman, MT
Over the years, in my daydreams on this subject–and I do daydream about this, it is how I mentally prepare myself for the possibility–the event always ends with an exhausted sigh of relief and the words: “We’re down safe, no damage, no injuries.”
This weekend trip began on Friday, October 26th, 2001. My employer, his wife and I began our flight to Harvey, North Dakota, from Pasco, Washington. Harvey is where all of my passengers grew up. My employer and his wife were remodeling a home there, so this was a working weekend for us.
At mid-day Saturday, my employer and I stopped work and went to the airport to refuel the plane, a Cessna 210. Since the temperature had dropped to the teens the night before, I wanted to see if it we would have any difficulty starting the engine in the cold. No problems there. After we were done refueling, I restarted the engine and taxied back to our parking spot. As I let go of the throttle in order to pull the mixture knob and kill the engine, the throttle rebounded forward about an inch and a half and the engine’s RPMs jumped up to about 1500. I grabbed the throttle again and pulled it back to idle, then let go of it. It moved forward again as if on springs. I wondered what might have gotten bent to cause this. And I wondered what else that could mean. I found it to be puzzling but not alarming, since it did not seem to effect the operation of the engine, except that it wouldn’t idle by itself below 1500 rpm.
Since there were no mechanics around and since this only seemed to be a minor nuisance, I decided that during Sunday’s takeoff, if I experienced anything unusual about the throttle or the engine’s full-power performance on the takeoff roll, I would abort the takeoff and we would stay another night until we could find a mechanic.
The takeoff at 11 a.m. central time on Sunday was uneventful. The engine attained maximum power and the throttle felt completely normal at the forward end of its travel. Although I still had some nagging reservations (and some guilt feelings) about departing with the undiagnosed “springy throttle” issue, I continued the takeoff roll and we started west.
I intended to follow the same route home across central Montana that we had used coming east and the flight went as expected. For over three hours I navigated mostly by dead reckoning (I didn’t have a GPS yet) and pilotage. Because of adverse weather, we flew low over some rather isolated grazing lands with the occasional ranch, cattle herd, water tank and missile silo for check points.
Eventually we got a solid lock on the Harlowton non-directional beacon and homed in to it on the 240-degree mag-bearing. As we approached Harlowton, I called flight service on the local remote outlet frequency, got an update on the weather, told them where I was, and that I had decided to land at Livingston to refuel.
About twenty minutes later we were circling to land on runway 4 at Livingston. The total flight time from Harvey to Livingston had been 3:38. During this landing, every time I let go of the throttle, the manifold pressure would jump back up to 22 or 23 inches. I put the landing gear down myself, but asked my right-seat passenger to push the propeller and mixture controls forward and to extend the flaps. That bothered me. What could be doing that, I wondered, and did it portend any other dangers?
At Livingston, there was no one around so we couldn’t refuel. We decided to continue to Bozeman for fuel and lunch. As we got back into the airplane I checked my kneeboard. We had used 67 gallons of fuel in just over three and a half hours. A glance at my scribbles on the board told me that the left tank had 20 gallons remaining and the right tank had 15 gallons. So I selected the left tank for takeoff.
Approaching Bozeman Airport, we were on a straight-in course for runway 30. The tower told me to report a 3-mile final, which I did, and received my clearance to land. Within a minute of that call, I reached up to the throttle, unlocked it, and reduced power a bit to begin a steeper final descent path and to slow the plane so I could extend the flaps. I then moved my right hand to the left, flipped the landing gear switch down, and returned my hand immediately to the throttle.
At that very moment, I felt an uncommanded movement in the throttle just as the engine power fell off. The springy throttle “something is bent in there” issue was still floating in the back of my mind, so I was immediately convinced that, somewhere, the throttle linkage had just broken and I had lost control of the engine.
I froze for just a moment, and then pushed the throttle in to see if I could add power. Nothing. Immediately, my training took command—and it is true, your training almost completely takes over. I stabbed the microphone button on the control wheel and told the tower: “Centurion Two Bravo Delta declaring an emergency, I have just lost my engine, we will be landing short.” The tower responded with a request for fuel and souls on board. I answered, and then focused on the job at hand.
Ahead of me was a farm field directly in line with the final approach path. But it seemed too short for my speed and altitude, and it was too uniformly brown. That implied to my mind that it had just been plowed (it had) and it would be too soft (it was). Landing there would risk flipping the airplane on its back and doing some expensive damage. The northern part of the field looked like it had some short vegetation in it. That implies a firmer footing. And it was longer. That field looked good.
I turned 45 degrees to the right and put the nose down to aim my glide path at a point about 50 to 100 feet short of where I wanted to touchdown, then I reached over to the flap handle and slapped it to full down. The timing for that action was perfect. With full flaps coming on, with their increase in drag, we were able to slow down and go down at the same time.
At the last moment on our glide down, my employer called out “Power lines!” I had seen them just at the same moment. He asked if we would be able to get over them. I said “No. We’re going under them.” That was not a conditional statement. I had decided years ago, that if power lines were ever an obstacle to an emergency landing, I would go under them. My recurring nightmare is to suddenly see wires in front of me and then find myself paralyzed with indecision, not knowing whether we should go up or down to avoid them.
Throughout the rest of the glide I remained focused on the power lines. We sailed under them and landed firmly 60 feet beyond. I was immediately relieved to feel that the soil was firm and not too bumpy. Without applying too much brake, we came to a stop in 700 feet.
As we rolled to a stop, the propeller was still turning at what looked like idle power. I reached to the mixture control, pulled it out and killed the engine. We were stopped, and we weren’t damaged. Then the tower called our N-number and asked how we were. I responded, “Tower, this is Two Bravo Delta. We are down safe, no damage, no injuries.” The tower controller responded with enthusiasm: “Bravo Zulu!” (…a Navy expression).
It took a little while, but soon Arlin Waas of Arlin’s Flying Service arrived on the scene with three of his employees. Arlin had his people tow the plane out of the field (gingerly), down the road (with the police stopping traffic for us at each end) and onto the airport property.
I told him what I had felt; about the springy throttle, and that I was sure the throttle linkage had let go. He removed the cowling and had a look. He asked me to get in the cockpit and move the throttle fully open and fully closed a number of times. He found that the throttle linkage was intact and working just fine. He did, however, find the reason for the springiness.
It turns out that another cable that is also connected to the throttle somehow seized up and got bent. This cable is connected to a box that activates the landing gear up-alarm. It is supposed to sound a horn anytime the throttle is closed and the wheels are in the up position. There was a 3-inch long Z-shaped bend in the wire, and that would account for the high idle problems.
Arlin asked me to open the throttle, prime the engine and start it. I did so, and it started, then quickly died. He then asked me to switch to the right main tank, prime and start. This time, the engine started normally, sustained itself, and I had speed control with the throttle. I was a little confused. It wasn’t the throttle linkage? Then what was that movement I felt? What about the springiness? How did that contribute to the problem–or did it?
Arlin walked over to my door and with a wry smile and a twinkle in his eye, quietly said, “You know, you can’t buy a good experience like this.” It will make you a better pilot, he implied. It all started to click in my mind. Had I really run the left tank out of fuel? But what about the engine as I rolled to a stop? Wasn’t it still running? Hadn’t I killed it with the mixture knob? The weight of it all hit me: No-o-o-o! I couldn’t have done that!! Running out of gas is something only stupid people do!
I grabbed my kneeboard and flight notes. When we were getting ready to leave Livingston, I had checked my fuel calculations. We had used 67 gallons of fuel in about three and a half hours, out of a total of 89 gallons in the mains, with another 30 gallons waiting in the tips tanks to be transferred.
At Livingston, my scribbles on the board told me that the left tank had 20 gallons remaining and the right tank had 15 gallons. So I had selected the left tank for takeoff. But, as it turns out, that wasn’t right.Those two figures for fuel remaining were written down when I last changed tanks at the 55-gallon point in the flight. Though I had recorded the final fuel burn tally on shutdown, I had failed to update the true fuel remaining in each tank after burning the last 12 gallons from the left tank during the last 35 or 40 minutes of the flight. Before landing at Livingston, I had switched to the right tank as part of the landing checklist and when I reviewed my fuel prior to takeoff, I moved the fuel selector knob from the right, back to the left. Its position, on the right tank, had been consistent with my flawed understanding of how much fuel was in each tank. I took off from Livingston assuming that I had 20 gallons in the left main tank when in fact I only had 8 gallons. Twenty minutes later the event began.
Lesson Learned? Besides the obvious: Familiarity breeds, if not contempt, then the complacency of routine. The danger in complacency is that it lowers our immunity to perceiving error by seducing us into dropping the guard that is found in wary skepticism.
Too much skepticism erodes the confidence we must have in our abilities as aviators and in the predictability of the machines we fly. Mild skepticism, however, whispers that we must continue to review our previous perceptions and conclusions–and take nothing for granted.
Aviators abhor uncertainty. We “Pilots in Command” like to think we know what is happening as we fly and that we are in control of all factors. (A dangerous conceit) As we go, we try to update our perceptions, establishing new expectations and alternatives, and setting and resetting the boundaries between the known and the unknown. But distractions and fixations can upset those efforts.
Conclusion? My principal mistake that set us up for the event was to glance at my kneeboard notes while starting up at Livingston. I should have checked my notes by reviewing the math and the logic by which they were derived. Instead I took for granted what I thought I saw and did not challenge my perceptions further.
Secondly, my fixation on the “springy throttle” issue overrode what should have been a knee-jerk reaction: When the engine lost power, the first thing I should have done was to change tanks, turn on the electric fuel pump, run the mixture forward a little and even move the throttle. I could have had the engine back in two seconds. But I failed to do that. At the time I had been certain the throttle linkage had separated and fuel was not the issue.
And yes, considering how it all turned out, I couldn’t buy a good experience like this. And it will make me a better pilot.