Flight Solely by Reference to Instruments

Objective

The CFI candidate will demonstrate the ability to teach attitude instrument flying techniques for helicopters, enabling a student to safely control the aircraft solely by reference to instruments during inadvertent IMC encounters. Upon completion, the student will understand instrument interpretation, cross-check techniques, and common errors while maintaining aircraft control within ACS standards per HI.XIII.D.

Content

Attitude Instrument Flying Elements (HI.XIII.D.K1)

Helicopter attitude instrument flying differs fundamentally from airplane operations due to the helicopter’s inherent instability and rapid control response. Unlike airplanes, helicopters require constant control inputs even in steady flight.

Straight-and-Level Flight:

• Attitude indicator is primary for pitch and bank
• Maintain level attitude with slight forward cyclic pressure
• Airspeed indicator primary for power (collective) control
• Heading indicator primary for directional control (anti-torque pedals)
• Cross-check sequence: attitude → airspeed → heading → altitude → attitude

Climbs:

• Attitude indicator shows climb attitude (typically 5-10° nose up)
• Power increase with collective, maintain RPM with throttle
• Airspeed control through cyclic pressure
• Monitor torque and engine parameters closely

Turns:

• Standard rate turns (3° per second) using attitude indicator
• Bank angle typically 15-20° for standard rate
• Increase collective slightly to maintain altitude
• Anti-torque pedal adjustment for coordination
• Lead rollout by half the bank angle

Descents:

• Attitude indicator shows descent attitude
• Reduce collective while maintaining RPM
• Control airspeed with cyclic
• Monitor rate of descent on vertical speed indicator

Instrument Interpretation and Limitations (HI.XIII.D.K2)

Pitch Instruments:

• Attitude indicator: Primary reference, shows immediate pitch changes
• Altimeter: Shows result of pitch changes, 1000-foot pointer most important
• Vertical speed indicator: Trend information, 6-9 second lag
• Airspeed indicator: Affected by pitch changes, 6-9 second lag

Bank Instruments:

• Attitude indicator: Primary reference for bank angle
• Heading indicator: Shows result of bank changes
• Turn coordinator: Shows rate of turn and coordination
• Magnetic compass: Unreliable during turns due to acceleration errors

Power Instruments:

• Manifold pressure or torque gauge: Primary power reference
• RPM indicator: Must maintain within limits (typically ±50 RPM)
• Engine temperature gauges: Monitor for power-related issues

Limitations:

• Attitude indicators: Tumbling limits (typically ±85° pitch, ±100° bank)
• Turn coordinator: Only accurate in coordinated flight
• Magnetic compass: Subject to turning errors, acceleration/deceleration errors
• Airspeed indicator: Lag time, position error at low speeds

Normal and Abnormal Indications (HI.XIII.D.K3)

Normal Indications:

• Attitude indicator: Stable, realistic aircraft symbol movement
• Engine instruments: Green arc operations
• Turn coordinator: Ball centered during coordinated flight
• Consistent instrument cross-check readings

Abnormal Indications:

• Attitude indicator: Tumbling, excessive precession, stuck display
• Engine instruments: Red line or caution range readings
• Airspeed indicator: Erratic readings, blocked static/pitot systems
• Compass system failures: Heading indicator precession

Recognition Techniques:

• Compare instrument readings for consistency
• Use backup instruments when available
• Recognize failure patterns (single instrument vs. system failure)

Physiology and Cross-Check Degradation (HI.XIII.D.R1)

Physiological factors significantly impact instrument flying ability:

Hypoxia: Even at low altitudes, stress-induced hypoxia can occur

• Symptoms: Euphoria, decreased judgment, tunnel vision
• Mitigation: Recognize symptoms, descend if possible

Fatigue: Degrades scan patterns and decision-making

• Results in fixation on single instruments
• Maintain disciplined cross-check sequence

Stress: Fight-or-flight response affects fine motor skills

• Causes over-controlling and fixation
• Use positive self-talk and breathing techniques

Medications/Illness: Can significantly degrade performance

• Know IMSAFE checklist implications
• Conservative approach to flight decisions

Spatial Disorientation and Illusions (HI.XIII.D.R2)

Types of Disorientation:

• Type I: Unrecognized (most dangerous)
• Type II: Recognized but pilot can’t correct
• Type III: Incapacitating

Common Illusions:

• Leans: Most common, occurs during unnoticed bank
• Graveyard spiral: Unnoticed descending turn
• Somatogravic illusion: Acceleration feels like pitch up
• Inversion illusion: Abrupt recovery from climb

Mitigation Strategies:

• Trust instruments over physical sensations
• Maintain disciplined scan pattern
• Use positive aircraft control inputs
• Avoid head movements when possible

Unfamiliar Aircraft Operations (HI.XIII.D.R3)

System Differences:

• Glass cockpit vs. analog instruments
• Different instrument layouts and procedures
• Autopilot integration and limitations
• Emergency procedures variations

Risk Mitigation:

• Thorough pre-flight briefing on systems
• Practice basic maneuvers in VMC first
• Identify reversionary modes and backup systems
• Know differences in control sensitivity

Common Errors (HI.XIII.D.K4)

Scan Pattern Errors:

• Fixation on single instrument
• Omission of critical instruments
• Irregular scan timing

Control Errors:

• Over-controlling due to instrument lag
• Chasing instruments instead of trending
• Improper control coordination

Procedural Errors:

• Incorrect power-pitch-trim sequence
• Failure to maintain appropriate scan
• Not utilizing all available instruments

Schedule

Equipment

Required References:

• FAA-H-8083-4, Helicopter Instructor’s Handbook, Chapter 8
• FAA-S-ACS-29, Helicopter Certified Flight Instructor ACS
• FAA-H-8083-15, Instrument Flying Handbook, Chapters 5-7
• POH/RFM for specific helicopter model

Materials:

• Helicopter with appropriate instrumentation
• View-limiting device (hood or foggles)
• Sectional chart for orientation
• Timer or stopwatch for timed maneuvers

Visual Aids:

• Instrument panel diagram or poster
• Control-performance relationship chart
• Scan pattern illustration
• Common error demonstration materials

Instructor Actions

The CFI candidate will:

1. Demonstrate comprehensive pre-flight briefing covering instrument limitations, emergency procedures, and physiological factors affecting instrument flight

2. Establish proper instrument conditions using view-limiting device while maintaining safety of flight and adequate outside references for safety pilot duties

3. Demonstrate and simultaneously explain straight-and-level flight technique showing proper scan pattern, control inputs, and trim usage while maintaining altitude ±100 feet and heading ±10°

4. Perform and teach constant airspeed climbs demonstrating power-pitch-trim sequence, explaining collective/cyclic coordination, and showing proper rollout technique to assigned altitude

5. Execute and explain constant airspeed descents showing power reduction technique, airspeed control methods, and level-off procedures at assigned altitude

6. Demonstrate standard rate turns explaining bank angle selection, coordination requirements, and rollout techniques while maintaining altitude ±100 feet

7. Identify and correct common student errors through positive instruction, showing recognition techniques and appropriate corrective measures

8. Teach risk management concepts explaining physiological factors, disorientation recognition, and appropriate responses to system malfunctions

9. Demonstrate effective communication using clear, concise instructions and positive reinforcement appropriate for instrument instruction environment

10. Show proper safety pilot procedures maintaining adequate visual references while student operates under simulated instrument conditions

Student Actions

The student (or DPE role-playing as student) will:

1. Acknowledge briefing items asking appropriate questions about procedures, limitations, and safety considerations

2. Demonstrate understanding of instrument categories and their primary/supporting roles in helicopter control

3. Attempt maneuvers as instructed showing progressive improvement in scan patterns and control techniques

4. Make typical student errors allowing CFI candidate to demonstrate recognition and correction techniques

5. Ask relevant questions about instrument interpretation, control techniques, and error recognition

6. Respond to scenario-based problems such as instrument malfunctions or unusual attitudes as directed by instructor

7. Demonstrate improvement in scan patterns and aircraft control throughout the lesson progression

8. Practice risk management decisions when presented with physiological factors or equipment limitations

Completion Standards

The CFI candidate demonstrates instructional competence when they can teach instrument flying techniques enabling the student to:

Knowledge Standards (HI.XIII.D.K1-K4):

• Explain the elements of attitude instrument flying for all basic maneuvers
• Describe instrument interpretation techniques and limitations for pitch, bank, and power instruments
• Identify normal versus abnormal instrument indications and appropriate responses
• Recognize and explain common errors in instrument flying techniques

Risk Management Standards (HI.XIII.D.R1-R3):

• Identify physiological factors that degrade instrument cross-check ability
• Explain spatial disorientation types and illusion recognition techniques
• Describe considerations for unfamiliar aircraft or display systems

Skill Standards (HI.XIII.D.S1-S6):

• Teach straight-and-level flight technique maintaining altitude ±200 feet, heading ±20°, and airspeed ±10 knots
• Demonstrate constant airspeed climb instruction maintaining airspeed ±10 knots and proper rollout to altitude ±200 feet
• Show constant airspeed descent instruction maintaining airspeed ±10 knots and level-off at altitude ±200 feet
• Teach proper instrument cross-check and interpretation with appropriate pitch, bank, and power control
• Integrate SRM/CRM concepts throughout instruction
• Identify, explain, and correct common errors using positive instruction techniques

The lesson meets HI.XIII.D standards when the CFI candidate demonstrates the ability to safely and effectively teach instrument flying skills while maintaining instructional competence and aircraft control within specified parameters.