The Human Factor: Unstable Personalities
After my article on overcoming go-around hesitation was published in the November 2012 issue of Flying, I received a message from Dr. Martin Smith about a study he and his associates at Presage Group Inc. conducted in conjunction with the Flight Safety Foundation. The goal of the study was to try to determine how commercial pilots’ situational awareness affects their safety and compliance with procedures and why pilots disregard go-around decisions required by FARs and company regulations on both visual and instrument unstable approaches. The study is part of a larger effort by the Flight Safety Foundation to identify the risks associated with a go-around.
Failure to go around during an unstable approach is the leading factor in approach and landing accidents and is also the primary cause of runway excursions. It is estimated that 97 percent of aircrews that find themselves in an unstable approach condition continue the approach and land. While the study was conducted mostly with professional airline pilots from many different areas of the world, with a median of 10,000 hours total time, I believe the same results would be true for general aviation pilots.
While the Flight Safety Foundation’s project is ongoing, there have already been some interesting results. A major point of the study was to determine the differences, if any, between pilots who tended to go around and pilots who usually continued an unstable approach. As often happens, the researchers found a bell-shaped curve, with 27 percent of the pilots reporting they had done go-arounds in the last five years but had not continued an unstable approach, 52 percent who had flown both unstable approaches and go-arounds and 21 percent who reported flying unstable approaches but no go-arounds.
So it appears that while about a quarter of all pilots are like the individual who wrote to say he can’t remember ever hesitating to go around when his approach was not stable, most pilots are likely to continue some or all unstable approaches in the hopes they can get the airplane back into a stable condition, or at least salvage a passable landing out of the unstable approach. The simple fact is that most of the time we get away with it; otherwise, the accident rate would be astronomical. However, every once in a while someone pushes it a little too far, or is a little too tired, or the conditions are a little worse than predicted, and a runway excursion or crash is the result.
I would fit in the peak of the curve with the majority of pilots. I have written about one experience in which I declared a missed approach just outside the outer marker in a Learjet 55 when I realized we prepared for the wrong approach. However, I also had an unstable approach experience in a Learjet 35. We left early in the morning from Houston Hobby to Washington National (now Reagan National). Our passenger returned early and stated that instead of heading home to Houston, he wanted to fly to Atlanta’s DeKalb Peachtree Airport. When we landed there, he told us he would be back later and left.
We were both asleep when he returned at about 1 a.m., ready to head home. It was my turn to fly, and I was still so groggy that I was barely aware of how we got to Flight Level 410. As we approached Houston at about 4 a.m., we were the only airplane on the approach control frequency, but the controller, who was also probably half-asleep, turned us onto the localizer inside the outer marker. As I was descending rapidly to try to capture the glideslope, I had a growing sense of discomfort in my fatigued brain. I was finally starting to realize I should declare a missed approach when we broke out of the clouds and were able to land visually, but I had taken the unstable approach much further than was prudent or safe.
In my unstable approach experience, fatigue and a desire to just get on the ground, combined with unanticipated and surprisingly poor vectoring by the approach controller, were the major factors. Detailed responses from the pilots who were surveyed by Smith showed that on nine interrelated situational awareness factors, pilots who tended to continue an unstable approach had scores that indicated they had less situational awareness than pilots who tended to go around rather than try to land out of an unstable approach. For example:
• They were less likely to be aware of a gut feeling that the approach was not stable or how to react if they did feel uneasy about the approach.
• They were less able to anticipate risk.
• They had more confidence in their ability to compensate for an unstable approach.
• They were less in agreement with their company’s standard operating procedures, including the criteria for when to execute a go-around.