If you know the cross-check sequence you are going to be aware of the hazard of fixation. You are far more likely to fixate on a movement. If the movement is not where it is supposed to be fixation is even more likely. As you detect, by quick glances, the movement of instruments you should note that some movements are in the proper direction and proper amount. Your scan sequence is seeking out the distinctions between what should be and what is.

As a basic instrument pilot you can improve your scan, cross-check, and seeing skill and speed. To make the improvement you must deliberately push you speed. You can't push your speed well unless you know where your eyes are supposed to move. You should avoid going back to a single instrument twice in a row. Never, is a dirty word in flying but it this instance it applies. If you know the information required for a given maneuver you can keep your cross-check moving through the instruments that have and give that information. Knowing where to look lets you see change as it happens. Seeing something happen must conform to your mental picture of what is supposed to happen. If the pictures are in conflict you press controls to bring the mental picture desired/required into an overlay of what the instruments show. Easy to say, not so easy to do at first.

Power, Attitude, Configuration = Performance Scan
An alternate to the FAA primary-secondary flight instrument scan is the PAC where the power setting, attitude and configuration selection gives performance. The PAC technique classifies the attitude indicator and tachometer as control instruments. Performance instruments are the AI, altimeter, HI, TC, and VSI.

The PAC is used in the takeoff as applied power, rotate to Vy attitude and configure. The climb is made first with power adjustment, pitch attitude and configuration. Cruise begins with power setting, attitude set and configure (cowl flaps). Descent sets power, pitch, and possible configuration change. Holding sets power, attitude and configuration. The non-precision and precision approaches begin with power, attitude, configuration as required for descent and tracking. The go-around begins with power, attitude, configuration, which way, how far and communications.

I must admit that I self-taught the PAC method to myself while flying a Link Trainer during two months at the end of

When teaching instruments I teach aircraft control first. I let my students get rid of the power, pitch and configuration problems of the aircraft. What is left can be scanned by a variety of methods. Even instruction in scan ultimately is blended into very individualized pilot specific methods. The absence of the AI ceases to exercise supreme importance once PAC is mastered. By making and mastering a PAC chart of the seven flight phases you are home free.

Flying Problems
Instrument flying problems usually are from faulty scan. Instrument interpretation, fixation, selection and control reactions individually or in combination cause a flight problem. Fixation on an instrument, the AI, is an acceptable procedure when redirecting the airplane, reacting to vertigo and flying in turbulence.

The most important element of a standardized scan is knowing when to look for what. Scanning fatigue occurs when we are moving our eyes without purpose. Try moving your eyes side to side a few times (15) and see what I mean. Also note that while your eyes are moving you cannot see anything. You will see without fatigue when your eyes are stopped and have been moved for a purpose.

General Solutions
Trick to break habit of rushing from one instrument to the next is to say aloud the indication and its significance... "Airspeed 90, O.K." AI wings level centered, O.K.". Process keeps scan slow enough to understand what is being seen and what you want to see.

Problem: Chasing the VSI or using the slope needle for pitch changes is an early cause of vertical S's on the glide slope.
Solution: Pitch changes are made on the AI.

Problem: S-turns while tracking a needle. Student is probably trying to fly plane 'level' by reference to HI.
Solution: Use a reference heading on the HI but hold the heading by reference to the AI..

Problem: Small variations of altitude.
Solution: Use pitch (AI) to correct. Above 100' use both AI and power for correcting.

Every pilot will have some flight/scan problem in one form or another. Be prepared to tell the instructor where you are looking during the scan and what is making you react as you do. Because of cockpit limitations the instructor can only guess as probable causes.

Instruction:
Make No-Peeky stick. Tack No-Peeky to 2 foot rod.

Turns to Headings
Cover HI Have student get to straight and level. Allow student a quick look of HI to note heading and a selected heading 90-degrees right or left. Cover HI and have student initiate 90-degree level turn using AI as rate indicator. Every airspeed has a AI angle for standard rate turns. Remove no-peeky two or three times for quick HI look so student can plan rollout to 90-degree heading. Intent is to show student that HI is only used occasionally and briefly during turns. Know when to look where.

Getting a Scan
You are moving your eyes across each instrument for information. Move the eyes too fast and you will lower your ability to make interpretations correctly. A slow scan can cause fixation. Initially, don't try for accuracy. Visualize putting the airplane where you want it by watching the attitude indicator.
--Scan from the AI to the TC and VSI to see the trend.
--Verify that the AI, TC and VSI are in agreement.
--Go to the numbers, altimeter, power, and HI
--Trim and begin total scan.

Knowing Where to Look
The competent IFR pilot knows what to look for and when to expect a change. He knows when to do something and how much of it to do. The Practical Test Standards (PTS) give the objectives and skill level requirements but don't tell how easy or difficult the acquisition may be. Most IFR students have 60 hours or instrument time before taking their checkride. I have found that calling the 'sound' of the airplane to the attention of the student will make them more aware and sensitive to the value of sound as a supplement the IFR scan.

Pitch; AI, Altimeter, VSI, Airspeed indicator
Power: Airspeed, Manifold pressure, RPM
Bank: AI, HI, TC, and Magnetic compass
Rate: TC, VSI, Clock, AI

Decide what you want. Decide where to look for the performance you seek. Greatest area of misinterpretation is in making compass turns without the aid of the clock. A normal scan is clockwise beginning with the AI. For a rate turn the initial scan begins counterclockwise from the AI. No one instrument gives all the information. Each instrument must be scanned to obtain confirmation of information either sought or required.

Climb to Level
1. --AI set(#1), then to altimeter and heading indicator (numbers) adjust AI(#1) then back to Alt and HI.
2. --Check trend. If unacceptable redo #1.
If acceptable go to #2 & # 3.
3. --Check the numbers information
Bank information is AI/TC or HI for constant heading (wings level)
Pitch information is airspeed/power, altimeter, or VSI
Power information is tachometer or airspeed

Climb and Descent-Scan
When climbing and descending at constant power, airspeed is primary pitch. To maintain airspeed during descent, lower nose on AI only and immediately reduce power to predetermined setting to hold airspeed. Trading airspeed for altitude or altitude for airspeed may be preferable. If both airspeed and altitude are high or low you must adjust both pitch and power. With gear down anticipate initiating descent with glideslope is 1/4 dot above center. Where manifold pressure is used for power the descent causes an increase. Power must be regularly reduced to maintain airspeed. A rule of thumb for establishing a 3 degree slope descent is to multiply your ground speed by 5 and add 50. Not exact but good enough.

Examples:
Climb
--Set attitude on AI
--Climb power
--Primary is altimeter
--Supporting is airspeed and VSI

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