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Aviation accidents come in all shapes, sizes and colors. However, studies, research, safety articles, books, trend analyses and mishap reports all point to the fact that 80% to 90% of aviation accidents have human factors as the primary cause. We have met the enemy and it is us!
It would seem that our minds become overloaded in certain circumstances. When I read an accident report and see things such as fuel pumps being set in high boost when the POH clearly says that will flood the engine and kill it, or pressing on into deteriorating weather (including high winds) when we all know that is an extremely dangerous thing for pilots to do...
...or failing to extend the landing gear, or leaving flaps set in the landing configuration on a go-around, or shutting down the wrong engine in a twin, or any of a host of other things, I wonder sometimes if flight training is not emphasizing the wrong things — which is to say, the study of the human animal and how it relates to the flight environment.
Usually when an accident occurs, it doesn’t just “happen,” with the possible exception of some mechanical failures. There is instead a sequence of events that leads up to it. As we read accident reports (perhaps we knew the pilot involved), you and I say to ourselves, “We just don’t understand it. How could someone with all that experience get into such a fix? Why, if only the pilot had feathered the engine” or “… if only the clouds hadn’t moved in so fast” or “if only this or if only that …” the accident never would have happened.
Investigators look at the events leading up to the accident to see if there is a point at which, if the pilot had done something else, the outcome might have been different. Starting with the accident itself, they look backward in time to reconstruct what happened. Radar tracks, witness interviews, conversations with the pilot or passengers, reviews of the pilot and aircraft logs, recent experience and training and surveys of the accident scene itself — all of these provide clues to what happened. The hard part is determining the why.
This sequence of events culminating in the mishap is called an accident chain. One of the clues can be the pilot’s physical and mental states: were there problems at home or work; what was the reason for the flight — pleasure, training, travel, etc.; when and what had he last eaten; how much sleep had he had; and so forth. Investigators might go back a few days, a week or more to see how these events might have affected this accident.
Not too long ago, there was a fatal accident in the mountains east of San Diego involving a relatively high-time (more than 3,000 hours) pilot and flight instructor in a somewhat low-powered general aviation aircraft. I have no special information about the accident, just what was in the news accounts in the media. I am not trying to assess blame or fault here. As it happened, I knew the instructor pilot; along with nearly everyone else, I liked him and had a great deal of respect for him personally as well as for his flight instructing and piloting talents. He apparently encountered a severe downdraft from a mountain wave on the lee (east) side of the mountains which forced him into the terrain about 300 feet below the ridge line.
So let’s take a look at this accident and see what clues there may be. Again, I have no special information, only what was in the local news media; there is no way I can assign blame or fault. But if my friend’s death is to have any meaning, we must learn from the events.
As I understand it, the instructor had sent his student, flying a Cessna 172, on a long cross-country flight. At the time of dispatch, the weather was good and expected to remain so. The route of the flight took the student to the lower Colorado desert of southern California, the last stop being Desert Resorts International, aka Thermal, just north of the Salton Sea.
Once the flight had begun, the pilot encountered stronger westerly winds than were forecast. This meant that he had good tailwinds for the first part of the flight, getting him to near the Colorado River in good time. On the return, however, the winds had picked up, so now he had a strong headwind on the remaining two legs of the flight home. The winds increased enough, in fact, so that by the time the flight reached Thermal the sun had set. The student did what I would hope my students would do: he landed, called the flight school and talked to his instructor. They decided that since it now was night, but still good VFR weather, discretion indicated that the CFI fly over and come back with the student since he had to be back at work the next morning.
This is indeed what happened. It was on the return to home base that the flight encountered the downdraft and flew into the ridge. The accompanying airplane with another CFI was a couple of thousand feet higher and had no problems other than the headwind.
The question in everyone’s mind was this: when he encountered the downdraft, why didn’t he just turn around and fly out of it? There was time, apparently, since he had to descend several thousand feet. His experience level would have indicated that he knew about mountain waves, and they’re certainly not uncommon around here. So, indeed, why not just turn around?
What follows is conjecture, but it illustrates the point that a mindset or a “sense of mission” can be very subtle in the same way that hypoxia affects a person’s judgment.
Remember the scenario: (1) it was a student pilot who (2) had to be back at work the next day so that (3) remaining overnight was not an option (neither was renting a car or taking the bus). He called his instructor who (4) now has a mission to “rescue” his student and once it’s completed, the instructor will be something of a hero because he saved the day. (5) The instructor had a schedule the following day, too, by the way. So step back and take a look — the flight is going to come home, at least in everyone’s mind.
Now let’s get into the 172, be talking to approach control and encounter the downdraft. The visibility is good enough to see the beacon at the home ’drome about 40 miles away. We meet the downdraft and my gosh! What’s going on here? We can’t maintain altitude. Even with full power the airspeed is dropping. “Approach, we can’t maintain our assigned 8,000.” “Roger, you’re cleared to 7,000.” “Approach, 7,000 won’t work, either — we’ll try six.” “Roger, but absolutely do not descend below 6,000!” This was the conversation over some ten minutes; the ridge elevation was 5,700’. So what happened? Why not turn away from the ridge??
What would turning away require? Why, they’d have to turn around and go away from their destination, back the way they came! Remember the scenario — they were all primed to get home — so the option to turn around probably never even occurred to him.
Have I been there, where I’ve talked myself into continuing when I shouldn’t have? You bet. I’m here to remember my failures, but this brings up a question all pilots need to answer for themselves to keep their options open: What mission or destination is worth your life?
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Aviation Training