1. Attitude Indicator 

a. Adjust miniature aircraft for level flight at normal cruise. 

b. Demonstrate similarity between the natural horizon and the horizon bar by placing the nose of the aircraft first above the horizon, then below it. 

c. Discuss the limits of operation. 

d. Demonstrate why the attitude indicator must be caged and uncaged in level flight (if a caging device is available). Stress the importance of fully uncaging the instrument. 

e. Reliable pitch attitude is indicated within approximately 30° in climbs and dives. In excess of 30°, the horizon bar is no longer visible or may lag. The extreme limits vary with instrument design. 

f. Acceleration and deceleration error. 
(1) Increase power rapidly from low to high - show loss of altitude while maintaining a level attitude on the attitude indicator. 
(2) Reduce power rapidly from high to low - show gain of altitude while maintaining a level attitude on the attitude indicator. 
(3) Hold altitude during power changes - show that the bar moves down on acceleration and moves up on deceleration. 

g. Comparison of movement of the miniature aircraft and the nose of the aircraft. The instrument gives a direct indication of pitch. 
(1) Adjust the miniature aircraft with the wings exactly centered on the horizon bar. 
(2) Change pitch attitude to 1/2 bar climb - student compares the movement of the aircraft's nose to the actual horizon. 
(3) Change pitch attitude to 1/2 bar descent - student compares to actual horizon. 
(4) Emphasize smooth control pressures and that 1/2 bar is recommended for small corrections. 

h. Student practice. 
(1) Maintaining level flight, keeping wings centered on horizon bar. 
(2) Making small pitch changes not to exceed 1/2 bar width. 
(3) Place aircraft in moderate climbs and descents and have student return to level flight. 
(4) Stress importance of smoothness and of not overcontrolling. 

2. Altimeter 

a. Constant altitude. 
(1) Maintain straight and level flight at a constant power setting. Point out that pitch attitude must also remain constant. 
(2) Raise the nose of the aircraft until the altimeter indicates a climb - show the relationship between increased pitch attitude and gain of altitude. 
(3) Lower the nose of the aircraft until the altimeter indicates a descent show the relationship between decreased pitch and loss of altitude. 

b. Determining pitch attitude by the altimeter. 
(1) Place the miniature aircraft well above the horizon bar. Point out the rapid change of the altimeter and the large change of pitch attitude shown on the attitude indicator. 
(2) Make small changes in pitch attitude - show slow change in altitude. Visualize the approximate change in pitch attitude by interpolating the rate of altimeter movement. 

c. Lag in the altimeter. 
(1) Make an abrupt pitch change and point out the momentary lag in the altimeter. 
(2) Make small, smooth pitch changes and point out that the altimeter, for practical purposes, has no lag. 

d. Proper technique for correcting altimeter movement. 
(1) Change pitch attitude to stop altimeter. 
(2) Change pitch attitude to return smoothly to desired altitude. 

e. Cross-check (division of attention) between altimeter and attitude indicator. 
(1) The cross-check is simple. Maintain level flight on the attitude indicator with frequent reference to the altimeter to determine that the altitude is being maintained. If an error is noted, correct it by making an appropriate correction on the attitude indicator. Guard against over controlling. 
(2) During level flight, the altimeter is primary for pitch and all changes in pitch are made so as to maintain a constant altitude. 

f. Student practice. 
(1) Maintaining a constant altitude. 
(2) Maintaining level flight by use of the attitude indicator and altimeter. 
(3) Lose or gain 50 feet by changing pitch attitude not more than 1/2 bar (emphasize small pitch changes). 
(4) Return to the original altitude, using the above technique. 
(5) Repeat this exercise until the student has acquired the proper cross-check and control technique. 

3. Vertical-Speed Indicator - Point out that the instrument reads zero when a constant altitude is maintained. The vertical-speed indicator is used both as a trend and a rate instrument. 

a. Use of the vertical-speed indicator as a trend instrument. Observe the vertical-speed indicator and altimeter as small pitch changes are made. Note that the vertical-speed indicator shows a trend up or down before the altimeter shows a climb or descent. 

b. Use of the vertical-speed indicator as a rate instrument in climbs and descents. 
(1) Establish a small attitude change and allow the vertical-speed indicator to "settle down" on a rate. The attitude change will give a particular vertical speed which will vary with different aircraft. 
(2) Caution the student not to "chase the needle," but to make small pitch changes, then wait for the needle to settle down. As a demonstration, put the aircraft into a climb or descent. With the needle of the vertical-speed indicator in motion, apply control pressures in the opposite direction to stop the trend. Have the student note that when the altimeter stops, the aircraft is passing through level flight attitude, and that simultaneously, the needle of the vertical-speed indicator is stopping and reversing its direction of movement. 

c. Use of the vertical-speed indicator to correct for deviations in altitude. 
(1) Raise the nose 1/2 bar. With a pitch attitude change of this magnitude, the vertical-speed indicator indicates a climb of about 200 feet per minute in low speed flight. (Explain that the relation between the attitude-indicator and the vertical-speed indicator depends on airspeed.) 
(2) For altitude corrections of 100 feet or less, use no more than a 200 feet per minute rate of climb or descent. A vertical speed in excess of this indicates overcontrolling. 
(3) For altitude corrections of more than 100 feet, make a correspondingly larger correction. 
(4) Lower the nose 1/2 bar. Show that the vertical-speed indicator indicates a rate of descent of about 200 feet per minute. 

d. Cross-check of pitch instruments. 
(1) Resume level flight. Cross-check the attitude indicator, altimeter, and vertical-speed indicator to detect any change in pitch attitude. Any deviation from zero by the vertical speed indicator shows a need for a pitch change. 
(2) Descend 50 feet below the desired altitude, then enter a climb of 200 feet per minute and return to the desired altitude. 
(3) Climb 50 feet above the desired altitude, then enter a descent of 200 feet per minute and return to the desired altitude. 

e. Student practice. 
(1) Attitude control with the vertical-speed indicator only. 
(2) Attitude control with the attitude indicator and the vertical-speed indicator. 
(3) Attitude control with the attitude indicator, vertical-speed indicator, and the altimeter. 
(4) Have the student climb 100 feet at a rate of 200 feet per minute. 
(5) Have student resume level flight, then descend at 200 feet per minute to the desired altitude. 
(6) Cross-check altimeter, attitude indicator, and vertical-speed indicator to maintain level flight. 
(7) Stress proper corrective pressures when correcting altitude. 
(8) Emphasize precision (correct small errors). 

4. Airspeed Indicator 

a. Use of airspeed indicator to determine attitude. 
(1) At constant power in level flight, point out that when altitude is constant, airspeed remains constant. 
(2) Make small changes in pitch and point out slow changes in airspeed. 
(3) Make extreme changes in pitch and point out fast changes in airspeed. 
(4) At cruising airspeed in level flight, have student climb or dive aircraft. Point out apparent lag. Explain that lag is caused by the time required for the aircraft to accelerate or decelerate after pitch has been changed. 
(5) Explain that there is no appreciable lag incorporated in the design of the instrument. 

b. Cross-check the attitude indicator, vertical-speed indicator, and airspeed indicator. As each instrument is added to the cross-check, the speed of the cross-check must be increased to afford adequate coverage of all instruments. (NOTE: Encourage the use of peripheral vision.) 

c. Student practice. With a constant power setting, hold constant airspeed in level flight by use of: 
(1) The airspeed indicator alone. 
(2) All available pitch instruments. 

5. Elevator Trim 

a. Application of elevator trim in pitch control. 
(1) Place aircraft in level flight, out of trim. 
(2) Point out pressures required to maintain desired pitch attitude. 
(3) Adjust trim to relieve pressure - show that aircraft flies "hands off." 
(4) In level flight, change airspeed. Point out the necessity of first holding pressure and relieving pressure with elevator trim. 

b. Student practice. Use of elevator trim in level flight. 
(1) With all pitch instruments. 
(2) Without the attitude indicator. 

NOTE - The instructor should aid the student in rudder and bank control throughout this lesson.