For the past two months I have concentrated on issues surrounding pitch attitude—what it does and how to trim for it. As promised, this month I plan to look at related issues: faith and magic. To start with, a little more on trim.
As I argued last month, you have to learn to trim to ensure a fighting chance in non-visual flight. There are two major goals: the first is to reduce workload and free up attention for chores other than altitude control, and the second is to permit brief periods of total diversion of attention away from the panel for chart review and ATC chores. Having learned how to trim, you must then invest the time—each time—necessary to make it work. Elevator trim is a process, not an event, and can seldom if ever be finished with a single whirl of the trim wheel.
Pilots who try to quit trimming early always end up having to come back over and over again, lost forever in a seemingly endless series of small under-and over-corrections. The escape from this treadmill, as I lectured last time, consists in the main of understanding that trim pressures never settle down until airspeed has stabilized. No matter how you try to hurry, every change in speed has the inevitable effect of changing trim. The value of this realization lies in two areas: first, once you understand the principle you won't be fooled into trying to quit early; second, you can avoid wasted time in attempts to fine-tune the trim setting before your airplane is fully ready to accept it.
LEARNING TO TRIM
Not surprisingly, the best place to learn the art of efficient and accurate pitch trim is in visual conditions: all mechanical flight skills are best tackled by assuring the greatest possible field of reference during the learning process. As a corollary, it is safe to conclude that every mechanical skill needs to be reliable and satisfactory in visual conditions before you attempt to transfer it to the world of instrument reference.
If you are having consistent problems in arriving at accurate instrument pitch trim settings, try removing the hood to concentrate briefly on your visual trim technique: you are likely find you have developed habits and techniques that you take for granted in visual conditions and then abandon on instruments. If this turns out to be the case, your problem is simplified: examine your techniques and find a way to transfer them to instrument reference—much easier than starting from scratch. If—and this is unlikely—you find you have just as much difficulty in visual conditions as in non-visual, you can take comfort in knowing you've found the right starting point: begin work on your visual trimming technique and make sure it is reliable before you re-enter the world of instrument reference.
Last month's column should prove helpful by adding to these observations some of the finer points in easing the job of finding and keeping a stable trim setting.
KEEPING THE FAITH
Once you have mastered techniques for establishing reliable pitch trim in basic hood work, you will probably find you continue to be plagued by trim issues unique to the instrument environment as you tackle more complex chores.
As an example, have you ever concentrated a bit too long on a puzzling ATC clearance or instruction, looked up at the panel only to find yourself 100 feet—or more—high? Most of us have at one time or another, and curiously, it's not always a matter of simply being out of trim. In fact, the situation often results from not really trusting the trim in the first place.
In my experience, many pilots, especially those at the start of their exposure to instrument flight, are not fully convinced that airplanes will really fly on their own when no one is watching. They might know it, they just don't believe it. The evidence of this lack of faith is the apparently unconscious effort to hold the plane up in the air with the left bicep when concentrating on other chores. After all, where's the harm? Sure, there are the wings and all of that, but a little added muscle might just make the difference between staying in the air and sliding uncontrollably down into terrain. This isn't just a nervous or incorrect control input: since the result is always a climb, you can conclude it is a deliberate, but not very well thought out, attempt to help the plane fly.
There is a corollary to this impulse that shows up in attempts to descend. Many students first learning to make approaches will cross a fix marking the start of an approach descent, reduce power and then mysteriously start to lose airspeed rather than altitude. What's wrong? It's that helpful left bicep again. With all those other issues to distract a pilot on the approach, it just seems reasonable to keep a helpful hand on the yoke to make sure the plane doesn't dive uncontrollably into the ground. Mind you, you don't want to stop the descent altogether, just ensure the process doesn't get out of hand. Left to its own, this impulse results in serious loss of speed and descents that lag significantly behind the demands of the procedure.
What is clearly at issue in both these situations is faith—faith your airplane really will maintain pitch attitude when properly trimmed, even if you aren't devoting 100% of your attention to it. If you find you are plagued by "unintentional" inputs of this sort, the cure is fairly straightforward—recognize the impulse for what it really is and move on.
MAGIC
At heart, the above situations actually have three root causes: lack of faith in the trim setting, an understandable reluctance to collide with terrain, and a general belief in magic, a description I reserve for all control inputs made while attention is diverted from the instruments. The term is appropriate: there is no other explanation for attempts to control an airplane in instrument conditions without instrument reference—it's not rational behavior.
As I said at the start, a major reason for instrument pilots to develop accurate and efficient trim techniques lies in the need to establish stable flight attitudes that can be relied on while attention is diverted from the panel for review of charts and other critical chores. It is during these moments of diverted attention that the temptation to make magical little inputs shows up.
If you ever make control inputs—aileron, rudder, or elevator—while looking away from the panel, the evidence is there: you believe in magic. It doesn't mean you are a bad person, it is just that you are clearly willing to rely on a source others can't perceive. In general, it is a big waste of time. Even if you are correct in your perception of the need to make an attitude change, there is no way to tell how much change you need to make. And worse, most often the perceived need is completely incorrect, a phantom created by random physical influences—momentum, acceleration, sound—that are inevitably targeted to fool the human sensory array.
In technical speak, the real issue is nothing more or less than "spatial disorientation." Although FAA and other expert publications are all aware of the issue, they seldom provide any advice except to "rely on the instruments." What I'm suggesting is a bit more primary: you should first look at the instruments. As an additional complication, the medical sounding "spatial disorientation" can lead you to expect spinning sensations and near-blackout. The reality is far more subtle—any time you come to believe your airplane is doing something it is not, you suffer from the ailment.
DISCIPLINE
When you become convinced your airplane is doing something undesirable with the instruments in view, the prescription is standard: make a disciplined crosscheck, then interpret and control. When the same thing happens at times you are not looking at the panel, discipline is again the key, but you must be sure to look back at the instruments before doing anything else. If you can bear a few more moments of unsupervised flight, continue with what you are doing. When you can't stand it any more, look up at the panel. One way or the other, the trick is not to do anything with your hands and feet that doesn't involve pencil and paper until you can see the instruments again.
That pretty well wraps up this series on pitch, power, trim and attitude control. In line with most elements of instrument flight, learning the theoretical data introduced at the outset, while important, turns out to be less useful for successful resolution of problems than developing appropriate pilot attitudes and thought patterns.
