Contents

Instrument Scan
There is a major difference between smooth air instrument scan and that necessary in turbulent conditions. A VFR pilot's minimum IFR skills are ability to fly by reference to attitude instruments to as to exit adverse weather. Inadvertent flight from VFR to IFR is still major cause of fatal accidents.

Scan
Music scan: One and two and …
Inverted V scan.

Pitch Altimeter
Power Manifold
Bank Heading

Scan Lessons
Trim for straight and level cruise. Cover all flight instruments except the AI. Do turns by using the 15-degree bank line below the horizon bar. Uncover other instruments one at a time. First comes the altimeter. Make small pitch changes up and down and then with turns always returning to the original altitude.

Cover the altimeter and uncover the HI. Use the AI to show how a wing low on the horizon bar will make little turns.
Practice 15-degree banks and coming out on headings using the 1/2 bank angle method.

Cover the HI and uncover the airspeed. Practice the power setting and pitch attitude needed for 90-knot climbs, descents and level as well as cruise flight. Practice the transitions using only the airspeed and the AI. Memorize the pitch, power, airspeeds and trim required in each case. Make a chart with drawings and numbers as required.

Final exercise is to leave only the TC and VSI covered. Repeat all exercises using this panel without TC and VSI.

Scan Method
The most common scan begins and ends with the AI. AI, altimeter, engine instruments, HI, AI. These are angular or oblique visual movements with the AI always peripherally in view. Partial panel scans tend to be more horizontal or vertical since they ignore the AI and HI.

Ready for IFR
FAA studies say that the amount of prior flight time has little effect on the acquisition and retention of instrument flight skills. Others believe that a certain amount of seasoning through independent flying is a good thing. No matter what kind of flying you do, you should be making improvements in your existing skills. There is no apparent advantage in waiting to get your instrument rating.

Regardless of how you plan to learn instrument flying, needle and ball, control and performance or primary and support, there are fundamentals that apply to all three. The flying of an approach is technique; the route, speed and altitudes are procedure. I would place the first requirement as aircraft control. You must be able to make the plane do as you want when you want. The mechanical operation of the aircraft power should be habitually ingrained into the pilot as to sound and throttle position. Likewise pitch can be preset for any flight condition by knowing the initial position and the amount of change required. Competence in these two flight skills considerably reduces the scan speed and changes required.

The pilot must be able to (1) fly the plane, (2) use the system, and (3) know where he is. The pilot must be able to fly, position, and operate the aircraft through a variety of configurations and performance parameters in such a way that flying does not get in the way of the other two elements above. There are at least ten distinctly different skills that must be mastered. The skills are inter-dependent and any weakness in one will be reflected in another. The smart pilot does everything possible to optimize the resources at his disposal. This necessitates standardization of procedures.

Pitch attitude, power settings, and trim position separately and/or in combination must be known to and achievable by the pilot. Being able to fly means being able to fly a heading, maintain an airspeed, remain on altitude, and make changes as required. The competent pilot is able to vary his attention to the proper place, on time and in sequence. He understands the principles of energy as it applies to flying. He uses his knowledge of instrument peculiarities as they interpret energy change.

Properly trimmed with wings level IFR is relatively simple as long as attention is paid and kept ahead of the aircraft. Use the rudder to keep things in order when you need both hands. Without rudder input holding headings and making heading corrections of less than 10 degrees is nearly impossible. Use the rudder to hold headings and make corrections of less than 5 degrees. It's quicker, more accurate, and less likely to induce a correction back in the other direction. Sure, it's a skid, just hold the wings level and kick the rudder as required. You can't begin to meet the scan requirements of IFR until you can fly your aircraft through all the required power settings and attitudes.

You must be able to make smooth rapid corrections that will average out the errors and keep the selected line of flight within limits. You should know approximate movements of yoke and throttle required. You will never exceed a standard rate bank. If a more rapid change is desired the movements may be made in excess for a few seconds but should then be normalized. Gentle wins every time. Pitch makes changes faster than power.

IFR is a complex combination of flight skills, cockpit management, communications, decisions and priorities. Of themselves any one choice is not difficult; it is in combination that difficulty rears its ugly head.

Scanning Scan
Successful instrument flying requires an ample supply of common sense and an understanding of the basic power and attitude give performance. Keep control input small and light but immediate. Scan in instrument flying depends on eye movement that are stopped just long enough on a given instrument to allow mental interpretation of what you see. The better you know the sounds of your aircraft from airflow and engine along with airspeed the better you will be able to sense changes in aircraft performance. You do not need to lose control just because one instrument fails.

When you are planning to redirect the aircraft into a change of attitude and power you can do well to move your eyes in a step series that moves every other time back to the AI while covering the other instruments in order. Once the aircraft is stabilized you can move around the panel in a rectangle. Only 2% of your flying will require any scan other than the rectangle. In turbulence you will revert to the V scan. When any one of the three legs of the V disagree with the other two, the single leg is in error. The bank V is the compass, AI and TC. You use the compass instead of the HI until you have confirmed that the vacuum system is working. The Pitch V is the AI, altimeter, and VSI.

Some pilots use the inverted V made up of the AI the TC and the VSI. From the AI you can set pitch bank attitude and angle. The VSI gives you trend and rate. The turn coordinator gives trend and rate of turn, coordination, and rate of roll. You can fine-tune your flying by using the turn coordinator and the vertical speed indicator. You will tend to over-control if you react to the VSI since it moves before the altimeter as does the TC to the roll before the AI.

Basic attitude instrument flying follows two paths, (1) primary and supporting instruments, and (2) attitude plus power equals performance. Regardless of the method you still must develop a set of performance numbers for each configuration of the airplane. The fewer numbers you have the better. For complex aircraft get the number(s) in the flap operating range. Use configuration to get down. Make a chart of performance and configuration for climbs, cruise, descents, and approach.

You want to know what your instruments are telling you. Knowing this, you need to make the instruments indicate the performance you are after.

The scan, or cross-check is probably best learned from a specialist. Some, like me, learned in a Link Trainer as my own teacher. What works for me is probably not desirable for you. Go to a simulator facility and take lessons specifically in cross-check skills. Even with the training you will put your own touch into how you scan.

Scan, done properly is the major fatigue factor of flying. You must move beyond looking, into seeing, and finally into understanding. (interpretation). The best illustration of this skill is one I used on rainy days while teaching elementary school. I would have a row of children put their heads down while I ‘hid' a coin in plain sight but in an unusual place. The children would then leave their seats and look for the coin.

The first one to see the coin would take their seat without revealing where the coin was. The coin would be looked at over and over but not seen. Some children always seemed to have better ‘seeing' skills than others. Some of the seers would grab at the coin instead of sitting down. Try it in the pilots lounge some time. Seeing is a developed skill. It can be taught.

Having a scan is not enough. Most any pilot can move his eyes in an ordered sequence as required for a particular maneuver. Doing the correct scan at the correct time at the correct speed is where the fatigue factor comes into play. A slow cross-check that suffices for level flight must shift gears when making a turn, shift still further when making a turning descent, and even further when making a timed turning descent to specific heading. Eye muscles can be trained for strength and rapid movement. Some opthamoligists/optometrists have a device to do this. The use of a computer generated panel may help but I question if the amount of movement meets actual cockpit requirements.

The competent basic instrument pilot must know the specific scan and speed required for every given situation. Steady state flight has a scan for level, descent, and climb. Turns add a new dimension and a new scan Different kinds of turns have still different cross-check requirements. You need to know and use the scan and cross-check required. A cross-check that lacks the proper speed, sequence, stop, and interpretation is going to break down. Fixing the results of an improper cross-check is much more difficult than getting it right and keeping it in the first place.

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