Instrument Ground Training Module 2

Randy Schoephoersterwww.airtreknorth.com

Agenda

• Turns• Turn Rates• Climbs and Descents• Fundamental Instrument Skills• Appropriate Instruments for IFR• Unusual Attitudes• Inoperative Instruments• Turbulence & Wind Shear

CAUTION…………………..

• The sole purpose of this class is to expedite your passing the FAA

knowledge test. With that said, all extra material not directly tested

on the FAA knowledge test is omitted, even though much more

information and knowledge is necessary to fly safely. Consult the

FAR/AIM (CFR) and other FAA Handbooks for further information along

with a Flight Instruction course.

UNOS – Magnetic Compass Dip (Turn) error

• Undershoot on turns to the North– Compass turns

opposite your turn initially

• Overshoot on turns to the South– Compass turns in the

same direction as your turn but faster

2.1 TURNS

1. An airplane requires a sideward force to make it turn.a. When the airplane is banked, lift (which acts perpendicular to the wingspan) acts

not only upward but horizontally as well.b. The vertical component acts upward to oppose weight.c. The horizontal component acts sideward to turn the airplane, opposing centrifugal

force.d. The rate of turn (at a given airspeed) depends on the magnitude of the horizontal

lift component, which is determined by bank angle.

2. A turn is said to be coordinated when the horizontal lift component equals centrifugal force (the ball is centered).

a. Centrifugal force is greater than horizontal lift in skidding turns (the ball is on theoutside of the turn).

b. Centrifugal force is less than horizontal lift in slipping turns (the ball is on the inside of the turn).

Ball on OutsideBall on InsideBall is Centered

3. To coordinate a turn, you should center the ball on the turn-and-slip indicator or the turn coordinator.

a. Center the ball by applying rudder pressure on the side where the ball is (e.g., if the ball is on the left, use left rudder).

4. A standard-rate turn is indicated when the needle is on the "doghouse" (i.e., standard rate) mark on the turn-and-slip indicator.

5. The angle of attack must be increased in turns to maintain altitude because additional lift is required to maintain a constant amount of vertical lift.

a. Thus, load factor always increases in turns (assuming level flight).

6. If airspeed is increased in a turn, the angle of bank must be increased and/or the angle of attack decreased to maintain level flight.

a. Conversely, if airspeed is decreased in a turn, the angle of bank must be decreased and/or the angle of attack must be increased to maintain level flight.

SUBUNIT 2.1: TURNS DETAILED OUTLINE INFORMATION

1. The lift produced by an airplane's wings is used to turn the airplane. When the wings are banked, the lift is separated into two components known as the vertical and horizontal components of lift.

• When the airplane begins to turn, centrifugal force, or inertia, pulls the airplane awayfrom the turn, i.e., tends to make it fly straight ahead.

• The horizontal component of lift (in a bank) counteracts the centrifugal force.

1) Therefore, the greater the bank, the sharper the turn or the greater the rate of turn because more of the total lift goes into the horizontal component.

2) The horizontal component of lift is the force that pulls an airplane from a straight flight path to make it turn.

2.2 TURN RATES

1. The standard-rate turn is 360° in 2 min., i.e., 3°/sec.a. A half-standard-rate turn is 360° in 4 min., i.e., 1.5°/sec.b. EXAMPLE: A 150° heading change using a standard-rate turn would take 50 sec.

(150° * 3°/sec. = 50 sec.)c. Rule of Thumb: (Airspeed/10) +7 = Standard Rate Turn Bank Angle

2. A turn and slip indicator may be calibrated as 2 minute or 4 minute.a. On a 2 minute turn and slip indicator, a single width deflection of the needle

indicates a turning rate of 3° per second, or a standard rate turn (i.e., 360° in 2 minutes).

b. On a 4 minute turn and slip indicator, a single width deflection of the needle indicates a turning rate of 1.5° per second, or a half rate turn (i.e., 360° in 4 minutes). If the needle is on the doghouse, it is indicating a standard rate turn.

3. At a constant bank, an increase in airspeed decreases the rate of turn and increases the radius of the turn.a. The rate of turn can be increased and the radius of turn decreased by decreasing

airspeed and/or increasing the bank.

Constant Angle of Bankvs Increasing Airspeed

At a constant bank, an increase in airspeed decreases the rate of turn and increases the radius of the turn.a. The rate of turn can be increased and the radius of turn decreased by

decreasing airspeed and/or increasing the bank.

Skid vs Slip

• Skid

• Slip

Slip vs Skid and how to get to a coordinated standard rate turn

• What do we do with rudder to coordinate?• What do we do with rate of turn for standard rate? Most of

us would think in terms of bank angle• Centrifugal force vs Horizontal Lift? Which is greater?

Skidding Turn Correction

Slipping Turn

Slipping Turn

Skidding Turn

Coordinated Turn

Aerodynamic Questions

Aerodynamic Questions

Aerodynamic Questions

Aerodynamic Questions

Standard Rate Turn

Standard Rate Turns

Standard Rate Turn

2.3 CLIMBS AND DESCENTS

1. Conditions that determine the pitch attitude required to maintain level flight area. Airspeedb. Air densityc. Angle of Attackd. Wing design

2. When leveling off from a climb or descent to a specific altitude, you must start the level-off before reaching the desired altitude.a. Throughout the transition to level flight, the aircraft will continue to climb or

descend at a decreasing rate.b. An effective practice is to lead the altitude by 10% of the indicated vertical speed.

1) Since the last 1,000 ft. of a climb or descent should be made at 500 fpm, you will generally use a lead of 50 ft.

c. To level off from a descent at a higher airspeed than descent speed, begin addingPower 100 to 150 ft. above the desired altitude, assuming a descent rate of 500 fpm.

Lead by 10%EX: 500fpm = 50ft

AAAW!

Level Off Procedure

Level Off Procedure

Level Off Procedure

Altitude ControlOff by less than 100ft

Another ViewSmall Correction in Altitude

Altitude Corrections

System Inoperative Instruments

• Break the instruments down into groups– Each instrument as it’s own failure– Pitot Failure

• Airspeed Indicator

– Static Failure• Altimeter• VSI• Small Error on Altimeter most likely

– Vacuum Failure• Attitude Indicator• Heading Indicator

Climbing turn to the rightConstant Speed

• Turn Coordinator Inop

Straight and Level flightVacuum System Failed

Climbing Turn to the RightAttitude Indicator Failed

Level Turn to the RightAirspeed should not be slow

• Pitot Tube Inlet

FUNDAMENTAL INSTRUMENT SKILLS DETAILED OUTLINE INFORMATION

1. During your attitude instrument training, you should develop three fundamental skills involved in all instrument flight maneuvers:

1. instrument cross-check, 2. instrument interpretation, and 3. airplane control.

2. Trim technique is a skill that should be refined for instrument flying.a. Cross-checking (also called scanning) is the continuous and logical observation

of instruments for attitude and performance information.1) You will maintain your airplane's attitude by reference to instruments that

will produce the desired result in performance.2) Since your AI is your reference instrument for airplane control and

provides you with a quick reference to your pitch and bank attitude, it should be your start (or home-base) for your instrument scan. You should begin with the AI, scan one instrument (e.g., the HI), and then return to the AI before moving to a different instrument.

3) Another type of instrument scan is called a "T" scan. Once again, the AI is the starting point. You should scan one instrument and then return to the AI, as shown below.

a) The TC and VSI are checked as required by the flight maneuver (e.g., straight-and -level, climbing, descending, or turning).

Constant RateTurn

Constant RateClimb/Descent

Three Fundamental Skills in Attitude Flying

Three Fundamental Skills Instrument Flying

Recovery from Unusual Attitude

Recovery from Unusual Attitudes

Recovery from Unusual Attitudes

4) Frequent cross-check faults area) Fixation, or staring at a single instrumentb) Omission of an instrument from cross-checkc) Emphasis on a single instrument, instead of on a combination of instruments

necessary for attitude information

5) The attitude indicator is at the center of the scan. Your cross-check patternshould include the attitude indicator as every second or third instrument scanned.

b. Instrument interpretation requires you to understand each instrument's construction, operating principle, and relationship to the performance of your airplane.

1) This understanding enables you to interpret the indication of each instrumentduring the cross-check.

2) Some instruments are quicker and more accurate than others.a) EXAMPLE: The airspeed indicator tends to need time to settle after a pitch or

power change before it portrays an accurate indication, while the attitude indicator gives almost instantaneous indication of pitch and bank changes.

c. Airplane control requires you to maintain your airplane's attitude or change it byinterpretation of the instruments. It is composed of three elements.

1) Pitch control is controlling the rotation of your airplane about the lateral axis bymovement of the elevators.

a) After interpreting the pitch attitude from the proper flight instruments, you will exert control pressures to effect the desired pitch with reference to the attitude indicator.

2) Bank control is controlling the angle made by the wing and the horizon.a) After interpreting the bank attitude from the appropriate instruments, you will

exert the necessary pressures to move the ailerons and roll your airplane about the longitudinal axis with reference to the attitude indicator.

b) The rudder should be used as necessary to maintain coordinated flight.

3) Power control is used when interpretation of the flight instruments indicates aneed for a change, e.g., excess or insufficient airspeed.

d. Trim is used to relieve all possible control pressures held after a desired attitude hasbeen attained.

1) The pressure you feel on the controls must be those that you apply while controlling a planned change in airplane attitude, not pressures held because you let the airplane control you.

2) An improperly trimmed airplane requires constant control pressures, produces tension, distracts your attention from cross-checking, and contributes to abrupt and erratic attitude control.

3) Always fly your airplane to a desired attitude, then trim.

2.8 TURBULENCE AND WIND SHEAR

1. In severe turbulence, set power for the design maneuvering speed (VA), and maintain a level flight attitude.

a. Attempting to turn or maintain altitude or airspeed may impose excessive load on the wings.

2. Flight at or below VA means the airplane will stall before excessive loads can be imposed on the wings.

3. When climbing or descending through an inversion or wind-shear zone, you should be alert for any sudden change in airspeed.

In Turbulence: Maintain at or below Va (maneuvering speed)

• Also, be wary of a sudden change in airspeed when climbing or descending through an inversion or wind-shear zone

Turbulence vs Airspeed

Agenda

• Turns• Turn Rates• Climbs and Descents• Fundamental Instrument Skills• Appropriate Instruments for IFR• Unusual Attitudes• Inoperative Instruments• Turbulence & Wind Shear