To start, you fly straight and level and adjust the attitude indicator (AI) and power accordingly. I then cover the other flight instruments - airspeed indicator, altimeter, vertical speed indicator (VSI), heading indicator, and turn coordinator (TC) - leaving you with only the AI for reference. Now, you execute turns and use a deck angle corresponding to two bar-widths above or below the horizon on the attitude indicator for climbs and descents. You do this over and over until you accept the validity of the axiom, "Attitude plus power equals performance." During this exercise, I insist that you call the AI the "trap door," because if you don't give it the attention it deserves, you'll think that the bottom fell out of the airplane.
Next, I uncover the turn coordinator and VSI, and you fly straight and level with these additional references. As your eyes move between the AI, TC, and VSI, you are scanning the "inverted V," an easy-to-remember way to identify this instrument group.
Now, you fly straight and level, and when the TC's turn rate and the VSI's climb rate are both zero, you'll know that you're executing the maneuver perfectly because the airplane is not turning, climbing, or descending. The trend of movement is just where you want it.
Now you execute turns, climbs, and descents using only the inverted V for reference. To do this, you must think of the TC and VSI as trend indicators. I call them the "fine tuners" because they give you qualitative information and react more quickly than the heading indicator or altimeter. Select the desired attitude and power setting and then scan the TC and VSI to see if the airplane's trend of movement is what you desire.
Then validate the attitude indicator by using the fine tuners. This step is of grave importance. Most instructors tell students to keep their eyes moving at all times, but this is a mistake. When you are making continual attitude changes, flying in moderate turbulence, or trying to recover from vertigo - everyone gets it - you must concentrate on the AI. This works only if the you know how to validate the trap door - determine that it's working properly.
Validating the trap door for pitch and bank information is a critical skill. For bank, compare the AI and the TC. Both should agree. For pitch, compare the AI and the VSI. Both should agree.
If a disagreement in bank information occurs, freeze. Stop and think! The AI is powered by the vacuum system, the TC by the electrical system. You must use an independent system to resolve this conflict. The magnetic compass is influenced by the earth's magnetic field. Does the magnetic compass movement agree with the TC or the trap door? The instrument that disagrees has failed (odd man out).
If a disagreement in pitch information occurs, again stop and think. The VSI is powered by the static system, and you must use the alternate static system to resolve this conflict. A pitch disagreement is not that critical. If you release the yoke, the airplane will attempt to regain the airspeed that existed when the elevator was last trimmed and you will notice changes in airflow noise, engine sound, and control pressure when airspeed gets excessively high or low. The bank disagreement is the killer. This is the conflict that leads to a graveyard spiral.
You must validate the trap door with the fine tuners. This is your insurance for staying out of the headlines if you inadvertently encounter IFR conditions.
Accidents are rarely caused by one problem. They happen because two or more problems occur simultaneously. A system failure during inadvertent instrument flight is a perfect example. To an improperly trained pilot, this would be incredibly confusing.
Finally, I uncover the remaining instruments, and you scan the ones that have the numbers you must maintain to comply with controller instructions or your desires. Flying the correct altitude and heading is one example. Only the altimeter and heading indicator will reveal that information.
Most instrument training manuals call these primary instruments, a misleading term that should be banished. Nothing could be further from the truth. They are priority number three, not number one, as the name implies.
Fortunately, you don't need to make it that complicated. Just ask yourself, "What numbers am I trying to maintain?" Then look at the instruments that give you those numbers. It's that easy.
Remember and practice these steps: (1) Set attitude and power for performance, and rough trim the elevator; (2) Scan the fine tuners for trends and the inverted V to validate the AI; (3) Scan the "primary" instruments to insure compliance with the numbers; and (4) Fine trim the elevator for hands-off flight.
Now you too can fly smart and safe when instrument conditions are inadvertently encountered.
