As a professional in underwater diving, and an amateur airman, I’ve been thinking a lot lately about the causes of accidents and “near-misses”. If you’re reading this in early 2014, you are no doubt aware of several recent incidents of commercial and military jets landing at the wrong airport. In the latest case there was a potential for massive casualties, but disaster was averted at the last possible moment.
As they say, to err is human. From my own experience, I know the truth of that adage in science, medicine, diving, and the subject of this posting, aviation. Pilot errors catch everyone’s attention because we, the public, know that such errors could personally inconvenience us, or worse. But lesser known are the sometimes subtle factors that cause human error.
I can honestly tell you exactly what I was doing and thinking that caused errors at the very end of long flights. Those errors, none of which were particularly dangerous or newsworthy, were nonetheless caused by the same elements that have been discovered in numerous fatal accidents. Namely, what I was seeing, was not at all what I thought I was seeing.
Long before the advent of GPS navigation, cell phones and electronic charts, I was flying myself and an Army friend (we had both been in Army ROTC at Georgia Tech) from Aberdeen Proving Ground, MD to Georgia. I was dropping him off in Atlanta at Peachtree-Dekalb Airport, and then I would fly down to Thomasville in Southwest Georgia where my young wife awaited me.
Since it was February most of the planned six hour flight was at night. We couldn’t take-off until we both got off duty on a Friday.
I had planned the flight meticulously, but I had not counted on the fuel pumps being shut down at our first planned refueling spot. After chatting with some local aviators about the closest source of fuel, we took off on a detour to an airport some thirty miles distant. That unplanned detour was stressful, as I was not entirely sure we’d find fuel when we arrived. Fortunately, we were able to tank up, and continue on our slow journey. We were flying in my 2-seat Cessna 150, and traveling no faster than about 120 mph, so the trip to Atlanta was a fatiguing and dark flight.
As we eventually neared Atlanta, I was reading the blue, yellow and green paper sectional charts under the glow of red light from the overhead cabin lamp. Lights of the Peachtree-Dekalb airport were seemingly close at hand, surrounded by a growing multitude of other city lights. Happy that I was finally reaching Atlanta, I called the tower and got no answer. No matter, it was late, and many towers shut down operations fairly early, about 10 PM or so. So I announced my position and intentions, and landed.
The runway was in the orientation I had expected, and my approach to landing was just as I had planned. However, as I taxied off the runway, I realized the runway environment was not as complex as it should have been. We taxied back and forth for awhile trying to sort things out, before I realized I’d landed 18 nautical miles short of my planned destination.
I had so much wanted that airport to be PDK, but in my weariness I had missed the signs that it was not. I had landed at Gwinnett County Airport, not Peachtree-Dekalb.
No harm was done, but my flight to Thomasville was seriously delayed by the two extra airport stops. It was after 1 AM before I was safe at the Thomasville, GA airport, calling my worried wife to pick me up.
She was not a happy young wife.
A few years later, I added an instrument ticket to my aviation credentials, and thought that the folly of my youth was far behind me. Now, advance quite a few decades, to a well-equipped, modern cross-country traveling machine, a Piper Arrow with redundant GPS navigation and on-board weather. I often fly in weather, and confidently descend through clouds to a waiting runway. So what could go wrong?
Wrong no. 2 happened when approaching Baltimore-Washington International airport after flying with passengers from the Florida Panhandle. Air Traffic Control was keeping me pretty far from the field as we circled Baltimore to approach from the west. I had my instrumentation set-up for an approach to the assigned runway, but after I saw a runway, big and bold in the distance, I was cleared to land, and no longer relied on the GPS as I turned final.
As luck would have it, just a minute before that final turn we saw President George W. Bush and his decoy helicopters flying in loose formation off our port side. I might have been a little distracted.
In the city haze it had been hard to see the smaller runway pointing in the same direction as the main runway. So I was lining up with the easy-to-see large runway, almost a mile away from where I should have been. It was the same airport of course, but the wrong parallel runway.
I was no doubt tired, and somewhat hurried by the high traffic flow coming into a major hub for Baltimore and Washington. Having seen what I wanted to see, a large runway pointed in the correct direction, I assumed it was the right one, and stopped referring to the GPS and ILS (Instrument Landing System) navigation which would have revealed my error.
The tower controller had apparently seen that error many times before and gently nudged me verbally back on course. The flight path was easily corrected and no harm done. But I had proven to myself once again that at the end of a long trip, you tend to see what you want to see.
Several years later I had been slogging through lots of cloud en-route to Dayton, Ohio. I had meetings to attend at Wright Patterson Air Force base. It was again a long flight, but I was relaxed and enjoying the scenery as I navigated with confidence via redundant GPS (three systems operating at the same time).
As I was approaching Dayton, Dayton Approach was vectoring me toward the field. They did a great job I thought as they set me up perfectly for the left downwind at the landing airport. But then I became a bit perturbed that they had vectored me almost on top of the airport and then apparently forgotten about me. So I let them know that I had the airport very much in sight. They switched me to tower, and I was given clearance to land.
As I began descending for a more normal pattern altitude, the Dayton Tower called and said I seemed to be maneuvering for the wrong airport. In fact, I was on top of Wright Patterson Airbase, not Dayton International.
Rats! Not again.
Well, the field was certainly large enough, but once again I had locked eyes on what seemed to be the landing destination, and in fact was being directed there by the authority of the airways, Air Traffic Control (ATC). And so I was convinced during a busy phase of flight that I was doing what I should have been doing, flying visually with great care and attention. However, I was so busy that my mind had tunnel vision. I had once again not double checked the GPS navigator to see that I was being vectored to a large landmark which happened to lie on the circuitous path to the landing airport. (I wish they’d told me that, but detailed explanations are rarely given over busy airwaves.)
Oddly enough, if I had been in the clouds making an instrument approach, these mind-bending errors could not have happened. But when flight conditions are visual, the mind can easily pick a target that meets many of the correct criteria like direction and proximity, and then fill in the blanks with what it expects to see. In other words, it is easy in the visual environment to focus with laser beam precision on the wrong target. With all the situational awareness tools at my disposal, they were of no use once my brain made the transition outside the cockpit.
To be fair, distracting your gaze from the outside world to check internal navigation once you’re in a critical visual phase of approach and landing can be dangerous. That’s why it’s good to have more than one pilot in the cockpit. But my cockpit crew that day was me, myself and I; in that respect I was handicapped.
Apparently, even multiple crew members in military and commercial airliners are occasionally lulled into the same trap. At least that’s what the newspaper headlines say.
My failings are in some ways eerily similar to reports from military and commercial incidents. Contributing factors in the above incidents are darkness, fatigue, and distraction. When all three of these factors are combined, the last factor that can cause the entire house of cards, and airplane, to come tumbling down, is the brain’s ability to morph reality into an image which the mind expects to see. Our ability to discern truth from fiction is not all that clear when encountering new and unexpected events and environments.
The saving grace that aviation has going for it is generally reliable communication. ATC saved me from major embarrassment on two of these three occasions.
I only wish that diving had as reliable a means for detecting and avoiding errors.