Fundamental Instrument Maneuvers

Attitude Instrument Flying

Attitude instrument flying means establishing the airplane’s attitude using the flight instruments rather than outside visual references.

Principles of Attitude Instrument Flying

Primary Rule: Attitude + Power + Configuration = Performance

• Pilots should learn what combinations of power, configuration, and attitude are necessary to attain their airplane’s desired performance. This reduces workload.
• Attitude changes should be held momentarily and then evaluated for performance. This prevents “chasing the needles.”

Fundamental Skills of Attitude Instrument Flying

Instrument Cross-Check (Scan): A continuous, systematic observation of the flight instruments. The preferred technique varies by individual pilot.

The purpose of the instrument scan is to:

• Help prevent spatial-disorientation and unusual attitudes.
• Provide early recognition of a failed instrument.

Instrument Interpretation: Combining all observations from the cross-check to determine the aircraft’s attitude and performance.

Aircraft Control: Applying the control responses necessary to fly the airplane.

The Four-Step Process Used to Change Attitude

1. Establish: Set the aircraft’s attitude (pitch and bank) and power to establish the desired performance.

• Pitch and bank changes are made in reference to the attitude indicator.
• Power changes should be set on the tachometer and, if equipped, the manifold pressure gauge.

To ease workload, pilots should become familiar with the approximate pitch and power settings required for each fundamental maneuver.

2. Trim: When the aircraft is trimmed properly, the pilot can relax pressure on the pitch control and momentarily divert attention to other tasks.

Trimming the aircraft is very important, and poor trim is one of the most common errors instructors note in instrument students.

3. Cross-Check: Verify the aircraft’s performance by scanning the flight and engine instruments.

4. Adjust: Adjustments for any deviations noted during the cross-check should be made in small increments.

Adjusting for Deviations

Pitch: The attitude indicator should be used to make corrections for altitude deviations. A rule of thumb is to establish a change rate of twice the altitude deviation, not to exceed 500 FPM.

Bank: The attitude indicator should be used to make corrections for heading deviations. A rule of thumb is to enter a bank angle equal to the number of degrees from the desired heading, not to exceed a standard-rate turn.

Power: Changes in power should be made with reference to the engine instruments and cross-checked on the flight instruments (airspeed, vertical speed, and altimeter). Pilots learn to approximate the required change in power through experience in the aircraft.

Attitude Instrument Flying Methods

There are two basic methods for learning to control the aircraft by reference to instruments: control and performance and primary and supporting. The methods differ in their reliance on the attitude indicator and interpretation of the other instruments.

Control and Performance Method

The control and performance method’s basic concept is to set a known combination of engine power and attitude (controls) to achieve the desired flight path and airspeed (performance).

Consistent Setup = Predictable Results

Scanning Technique: The attitude indicator is the center of focus; therefore, the selected radial or T-scan is recommended.

Instrument Groups:

• Control: The attitude indicator and power instruments (tachometer and manifold pressure, if equipped).
• Performance: The altimeter, airspeed indicator, and vertical speed indicator. Other instruments are the heading indicator and the slip/skid indicator.
• Navigation: Ground-based or space-based navigation systems.

Basic Concept:

• All attitude changes should be made in reference to the control instruments (attitude and power).
• Once established, make note of the power settings and flight instrument indications.

Primary and Supporting Method

The primary and supporting method’s basic concept is to understand how each component of the aircraft’s attitude (pitch, bank, and power) is most effectively monitored for performance. Less emphasis is placed on the attitude indicator.

Scanning Technique: The eyes should spend the most time on the primary instruments.

Instrument Groups:

• Primary: The instrument that displays the most pertinent information at any given time. There are three primary instruments for every maneuver: one for pitch, one for bank, and one for power.
• Supporting: The instruments that back up the primary instruments. There may be more than one supporting instrument for pitch, bank, and power.

Basic Concept:

• When transitioning between maneuvers, use the attitude indicator and power instruments (tachometer and manifold pressure, if equipped).
• Once established, begin scanning with proper emphasis on the primary and supporting instruments.

Instrument Scanning Techniques

Inverted V Scan

• Starting Position: Attitude indicator (home base)
• Eye Movements:
• From the attitude indicator to the turn coordinator and back
• From the attitude indicator to the vertical speed indicator and back

T-Scan

• Starting Position: Attitude indicator (home base)
• Eye Movements:
• From the attitude indicator to the airspeed indicator and back
• From the attitude indicator to the heading indicator and back
• From the attitude indicator to the altimeter and back

Selected Radial Scan (Hub and Spoke)

• Starting Position: Attitude indicator (home base)
• Eye Movements:
• From the attitude indicator (hub) to an instrument (spoke) and back
• The eyes are on the attitude indicator 80–90% percent of the time

Rectangular Scan

• Starting Position: Attitude indicator
• Eye Movements: From one instrument to the next in a box pattern (either direction)
• Best Uses: To rapidly scan all instruments for trends or instrument errors

Instrument Scanning Errors

Fixation: Staring at a single instrument, which often leads to an unnoticed change in other instruments.

Common reasons for fixation:

• Uncertainty or confusion with an instrument indication.
• Attempting to maintain or set an unnecessarily tight tolerance on a digital instrument.

Omission: Neglecting to include an instrument in the cross-check.

Common reasons for omission:

• An instrument that is installed in an awkward position, such as a stand-by instrument on the lower panel.
• Only scanning the primary flight display (PFD) due to its high reliability and ease of use.

Emphasis: Placing more attention on a single instrument instead of a combination of instruments.

Common reasons for emphasis:

• Elevating the importance of one instrument above another.
• Relying on the instrument that is most readily understood, even when it provides inadequate information.

Straight-and-Level Flight by Reference to Instruments

Procedure

1. Establish:

• Adjust the aircraft’s attitude and power setting to establish level flight at a constant airspeed.
• Altitude is to be maintained with zero bank and no yaw (constant heading).

2. Trim:

• Relieve all flight control pressures after a level attitude has been attained.
• The airplane should be able to maintain straight-and-level flight momentarily without any control inputs.

3. Cross-Check:

• Begin scanning with your preferred technique.
• Make a conscious effort to avoid scanning errors (fixation, omission, and emphasis).

4. Adjust:

• Make smooth and small corrections with positive control pressure.
• Avoid making large corrections that result in rapid attitude changes.
• Know and apply rules of thumb to correct for deviations in pitch and bank.

Common Errors for Straight-and-Level Flight

• Faulty trim procedure
• Insufficient cross-checking and interpretation of the instruments
• Fixation, omission, and emphasis errors during instrument cross-check
• Making excessive attitude corrections (“chasing the instruments”)

Constant Airspeed Climbs and Descents by Reference to Instruments

Procedure

Constant Airspeed Climbs:

• Raise the miniature aircraft to the nose-high indication for the predetermined climb speed. The attitude depends on the airplane’s performance.
• To climb at the current speed, set climb power simultaneously with the pitch change.
• To climb at a slower speed, set climb power after the pitch change is established and the airspeed decreases to the climb speed.

Constant Airspeed Descents:

1. To descend at a slower speed, reduce power and slow to the descent speed while maintaining straight-and-level flight.
2. Simultaneously lower the nose and reduce power to begin the descent.
3. Once established, trim to relieve all flight control pressures.
4. Scan the instruments with your preferred technique.

5. Use smooth, small pitch adjustments to correct for airspeed deviations.

Level-Off Procedure:

• Lead the level-off from the desired altitude by 10% of the vertical velocity.
• Simultaneously adjust power and pitch to return to level flight.
• To level-off from a climb at a faster speed, pitch to return to level flight, then reduce power after reaching the cruise speed.

Vertical S’s (Practice Flight Pattern)

Common Errors for Constant Airspeed Climbs and Descents

• Overcontrolling pitch on climb entry
• Failure to trim off new control pressures
• Failure to learn and use proper power settings
• “Chasing” the vertical speed indicator
• Failure to note the rate of climb or descent to determine the lead for level-offs

• “Ballooning” (allowing the nose to pitch up) on level-offs from descents

Turns to Headings by Reference to Instruments

Standard-Rate Turns

A standard-rate turn is a change in heading at a rate of 3° per second. The bank angle required to maintain a standard-rate turn varies with the true airspeed (TAS).

The bank angle for a standard-rate turn can be approximated with the following formula.

Bank Angle for Standard-Rate Turn = (KTAS ÷ 10) + 5

Procedure

1. Establish:

• Use the attitude indicator to establish the bank angle for a standard rate turn.
• Verify a standard rate turn on the turn coordinator (or turn-and-bank indicator).
• Apply aft control pressure on the pitch control to stop any altitude loss.

2. Trim:

• Relieve all flight control pressures after a level turn has been attained.

3. Cross-Check:

• Begin scanning with your preferred technique.
• Make a conscious effort to avoid scanning errors (fixation, omission, and emphasis).

4. Adjust:

• Make smooth and small corrections with positive control pressure.
• Use the same procedures as in level flight to control the airspeed and altitude once the maneuver is established.

Rollout Procedure:

1. To stop the turn on the desired heading, lead the rollout by about one-half the bank angle.
2. Strive for the same rate of rollout used to roll into the turn.
3. Apply forward control pressure on the pitch control to stop any ballooning (altitude gain).
4. If trim was used in the turn, retrim to relieve all flight control pressures.

S-Turns Across a Heading (Practice Flight Pattern)

Common Errors for Turns to Headings

Altitude Errors Resulting From:

• Preoccupation with bank control during turn entry and rollout
• Erratic rates of bank change on entry and rollout
• Failure to make pitch adjustments as the vertical lift component changes, resulting in a loss of altitude on entry and a gain of altitude on rollout
• Failure to trim during turn entry and following rollout (if the turn is prolonged)

Heading Errors Resulting From:

• Overcontrolling during turn entry and rollout
• Failure to use the proper degree of bank for the amount of heading change desired
• Failure to check the ball/brick when interpreting bank information
• Failure to remember the heading to which the aircraft is being turned due to preoccupation or rushing the maneuver

Timed Turns and Compass Turns [IFR]

Timed turns and compass turns are practiced using full-panel and partial-panel procedures to develop the learner’s ability to make accurate turns to headings without the use of the directional gyro.

Primary and Supporting Instruments

The attitude indicator, if available, is used to establish the approximate bank angle when beginning a turn. Once the turn is established, the turn coordinator becomes the primary instrument for bank control, the altimeter for pitch control, and the airspeed indicator for power control.

Procedure for Timed Turns

1. Determine the amount of time it will take to turn to the specified heading at a rate of 3° per second (standard rate turn).
2. Begin timing at the point where the airplane begins to roll into a bank.
3. Begin the rollout once the time has elapsed at the same rate used during the roll-in.

Procedure for Compass Turns

Considerations:

• The compass tends to lead on northerly headings and lag on southerly headings. The amount the compass leads or lags is affected by the degree of latitude.
• Account for the amount of time it takes to roll out of the turn. Consider using the 1/2 bank angle rule of thumb.
• No correction is needed when turning to an east or west heading.

Compass Turns to the North

Rule of Thumb: Stop the turn 15° plus half of the latitude before reaching the desired heading.

Compass Turns to the South

Rule of Thumb: Stop the turn 15° plus half of the latitude after passing the desired heading.

Oscar Flight Pattern

The Oscar pattern is an instrument flying exercise that combines standard-rate turns with constant airspeed climbs and descents.

The objective of the Oscar pattern is to:

• Develop instrument scanning techniques
• Build a foundation of skills that will be used in IFR procedures
• Prepare the learner to operate in a high-workload environment

Procedure

Pre-Maneuver Checks:

• Clear the area
• Heading established and noted
• Altitude established
• Position near a suitable emergency landing area
• Set power and aircraft configuration:

• Do not exceed V_A or V_O

During the Maneuver:

• Airspeed remains constant (power is adjustable)
• All turns are 360° and made at standard-rate
• All climbs and descents are made at 500 FPM
• Each period of straight-and-level flight should last 30 seconds (use a timer)

Variations for Added Complexity:

• Perform a flow check and checklist for each climb, descent, and level-off
• Perform the maneuver with a partial panel or using the standby instruments
• Brief an instrument approach

Airman Certification Standards for Basic Instrument Maneuvers