Objective
The CFI candidate will demonstrate the ability to teach autorotation with turns in a single-engine helicopter. Upon completion of instruction, the student will understand the elements of autorotation with turns, identify and manage associated risks, and demonstrate competency in executing the maneuver to ACS standards. This lesson addresses ACS task HI.XII.C and its associated knowledge, risk management, and skill requirements.
Content
Introduction to Autorotation with Turns
Autorotation with turns represents one of the most critical emergency maneuvers in helicopter operations. Think of it as threading a needle while riding a rollercoaster—you must maintain precise control of energy and attitude while navigating toward a specific target. This maneuver combines the fundamental autorotation technique with deliberate turns to position the helicopter for landing in a selected area.
Elements Related to Autorotation with Turns (HI.XII.C.K1)
The primary elements of autorotation with turns include:
Entry Phase: Immediate recognition of power failure, lowering collective to enter autorotation, establishing proper airspeed, and maintaining rotor RPM within limits while planning the turn sequence.
Glide Phase with Turns: Managing energy through coordinated turns while maintaining autorotation airspeed, monitoring rotor RPM, and positioning for the selected landing area. Bank angles directly affect descent rate and forward speed.
Recovery Phase: Rolling out of turns no lower than 300 feet AGL, executing proper flare technique, and managing collective application for safe landing or power recovery.
Effects of Environmental Factors (HI.XII.C.K2)
Wind Effects: Headwinds increase glide ratio but may require steeper approaches. Tailwinds decrease glide ratio and increase ground speed. Crosswinds require drift correction during turns and final approach. Wind shear can dramatically affect energy management.
Weight Effects: Heavier aircraft have increased descent rates and require higher airspeeds for optimal glide performance. Energy management becomes more critical with increased weight.
Temperature and Density Altitude: High density altitude reduces rotor efficiency and increases descent rates. Performance decreases significantly, requiring earlier commitment to landing areas and more conservative energy management.
Various Rotor Systems and Autorotation Effects (HI.XII.C.K3)
Fully Articulated Systems: Provide greater stability in autorotation but may have slower rotor acceleration characteristics. Bank angle changes affect rotor disc loading differently.
Semi-Rigid Systems: Typically demonstrate quick response to control inputs but may be more sensitive to improper energy management during turns.
Rigid Systems: Offer precise control but require careful attention to G-loading during turning maneuvers in autorotation.
Main Rotor RPM Management (HI.XII.C.K4)
Rotor RPM is your energy bank account. During turns in autorotation, centrifugal force and changing angles of attack affect RPM. Steep banks can cause RPM decay, while rolling out may cause RPM increase. The pilot must anticipate these changes and use gentle collective inputs to maintain RPM within the green arc.
Energy Management Principles (HI.XII.C.K5)
Energy management in autorotation with turns involves three types of energy:
Kinetic Energy: Forward airspeed converts to lift during flare. Turns affect airspeed, requiring careful planning.
Potential Energy: Altitude converts to rotor RPM and forward speed. Each turn consumes energy through increased drag.
Rotational Energy: Stored in the rotor disc, this energy provides the final cushioning for landing. Mismanagement during turns can lead to insufficient energy for safe landing.
Causes and Effects of High Descent Rates (HI.XII.C.K6)
High descent rates result from:
- Airspeed below optimal glide speed
- Excessive bank angles during turns
- High density altitude conditions
- Improper collective management
Effects include insufficient time for proper landing preparation, increased risk of hard landing, and potential rotor stall if recovery is attempted with insufficient altitude.
Effects of Varying Parameters (HI.XII.C.K7)
Bank Angles: Moderate banks (15-30 degrees) efficiently change direction with minimal energy loss. Steep banks increase descent rate and decrease glide distance. Banks over 45 degrees dramatically increase descent rate and can lead to rotor stall.
Airspeeds: Below optimal glide speed increases descent rate and reduces glide distance. Above optimal speed may provide better rotor RPM but reduces overall glide performance.
Rotor RPM Variations: Low RPM reduces control authority and increases risk of rotor stall. High RPM may indicate energy mismanagement or improper collective position.
Common Errors (HI.XII.C.K8)
- Initiating turns too early without establishing stable autorotation
- Excessive bank angles leading to high descent rates
- Poor energy management resulting in insufficient flare capability
- Failing to roll out by 300 feet AGL
- Improper collective management during turns
- Inadequate clearing and area selection
Risk Management
Low Entry Altitudes (HI.XII.C.R1): Insufficient altitude limits options for maneuvering and energy management. Always ensure adequate altitude for complete maneuver execution.
Flight Control Inputs (HI.XII.C.R2): Abrupt or excessive control inputs can induce dangerous flight attitudes or rotor stall. Use smooth, coordinated inputs throughout the maneuver.
Turbulence and Wake Turbulence (HI.XII.C.R3): Turbulence affects rotor efficiency and control response. Avoid areas of known turbulence and maintain situational awareness of other aircraft.
Windshear (HI.XII.C.R4): Sudden wind changes can dramatically affect glide path and energy management. Be prepared for rapid airspeed and attitude changes.
Energy Management (HI.XII.C.R5): Continuously monitor energy state throughout turns. Plan conservative approaches and maintain energy reserves for landing flare.
Main Rotor RPM (HI.XII.C.R6): Monitor RPM closely during turns and be prepared to adjust collective as needed. Never allow RPM to drop below limits.
Low Rotor RPM or Rotor Stall (HI.XII.C.R7): Recognize early signs of rotor stall including vibration, loss of control effectiveness, and rapid RPM decay. Immediate corrective action includes lowering collective and reducing bank angle.
Excessive Rate of Descent (HI.XII.C.R8): Monitor vertical speed continuously. If descent rate becomes excessive, reduce bank angle and verify optimal autorotation airspeed.
Powerplant Failure During Maneuver (HI.XII.C.R9): If practicing autorotation and actual power failure occurs, continue with the maneuver to a safe landing. Do not attempt power recovery.
Rolling Out of Turn (HI.XII.C.R10): Plan rollout to occur no lower than 300 feet AGL along the flight path to the landing area. Coordinate rollout timing with altitude and distance to target.
Collision Hazards (HI.XII.C.R11): Maintain visual contact with other aircraft and obstacles. Use proper radio calls and clearing procedures.
Terminating Autorotation (HI.XII.C.R12): Ensure adequate altitude and energy for safe termination. Brief termination method (power recovery or touchdown) before beginning maneuver.
Power Recovery and Go-Around (HI.XII.C.R13): If performing power recovery, ensure adequate rotor RPM and proper control positions. Be prepared for immediate go-around if termination becomes unsafe.
Distractions and Loss of Situational Awareness (HI.XII.C.R14): Maintain focus on primary flight instruments and outside references. Avoid fixation on any single parameter.
Schedule
| Time | Activity | Content Focus |
|---|---|---|
| 0-5 min | Introduction | Lesson objectives, maneuver overview |
| 5-15 min | Theory Discussion | Elements, environmental factors, energy management |
| 15-25 min | Risk Management | Hazard identification, mitigation strategies |
| 25-35 min | Demonstration Flight | CFI demonstrates complete maneuver |
| 35-45 min | Student Practice | Guided practice with immediate feedback |
| 45-55 min | Error Analysis | Common errors, correction techniques |
| 55-60 min | Evaluation/Debrief | Performance assessment, lesson conclusion |
Equipment
Required References
- FAA-H-8083-21A Helicopter Flying Handbook (Chapter 11)
- FAA-H-8083-4 Helicopter Instructor’s Handbook
- FAA-S-ACS-29 Helicopter ACS
- POH/RFM for specific aircraft
- Current sectional chart
Visual Aids
- Autorotation diagram showing turn phases
- Energy management chart
- Rotor RPM vs. bank angle graph
- Landing area selection criteria checklist
Equipment
- Training helicopter with autorotation capability
- Current weight and balance data
- Performance charts for current conditions
- Radio for traffic coordination
- Designated practice area with suitable landing options
Instructor Actions
The CFI candidate will demonstrate comprehensive instructional ability by:
Pre-flight Briefing: Complete pre-maneuver briefing covering objectives, procedures, risk factors, and completion standards per ACS requirements HI.XII.C.
Area Preparation: Clear the practice area systematically, make appropriate radio calls per HI.XII.C.S2, select suitable landing area per HI.XII.C.S4, and establish entry altitude per HI.XII.C.S5.
Maneuver Demonstration:
- Complete appropriate checklist per HI.XII.C.S1
- Initiate maneuver at proper point per HI.XII.C.S6
- Establish autorotation airspeed ±5 knots per HI.XII.C.S7
- Maintain rotor RPM within normal limits per HI.XII.C.S8
- Execute planned turns while explaining energy management principles
- Demonstrate maneuvering to avoid undershooting/overshooting per HI.XII.C.S9
- Roll out no lower than 300 feet AGL per HI.XII.C.S10
- Show proper deceleration and collective application per HI.XII.C.S11
- Execute briefed termination (power recovery or touchdown) per HI.XII.C.S12
- Achieve stabilized hover or surface touchdown within 100 feet per HI.XII.C.S13
Error Recognition: Demonstrate ability to identify and correct common errors per HI.XII.C.S14, providing immediate feedback and correction techniques.
Teaching Techniques: Use clear explanations, appropriate analogies, and progressive instruction methods while maintaining aircraft control and situational awareness.
Student Actions
The student (evaluator role-playing) will:
Participate Actively: Ask relevant questions about energy management, environmental factors, and emergency procedures during ground instruction.
Practice Maneuver Elements: Attempt to perform autorotation with turns under CFI guidance, making expected student errors for correction demonstration.
Respond to Instruction: Show appropriate learning progression, from initial confusion to improved performance with instruction.
Simulate Emergency Scenarios: Present realistic scenarios such as “What if winds shift during the maneuver?” or “How would you handle turbulence during the turn?”
Request Clarification: Ask for clarification on complex concepts like energy management and bank angle effects to test instructor’s teaching ability.
Demonstrate Learning: Show improvement in maneuver execution through the lesson progression.
Completion Standards
The CFI candidate successfully completes this lesson when they demonstrate the ability to teach autorotation with turns to ACS standard HI.XII.C. Specific completion criteria include:
Knowledge Instruction: Accurately explain all knowledge elements (K1-K8) including autorotation turn elements, environmental effects, rotor system variations, RPM management, energy principles, descent rate factors, parameter effects, and common errors.
Risk Management Teaching: Effectively communicate all risk factors (R1-R14) and appropriate mitigation strategies, demonstrating thorough understanding of hazard recognition and management.
Skill Demonstration: Perform all skill elements (S1-S14) to ACS standards while providing clear, concurrent instruction:
- Maintain autorotation airspeed within ±5 knots
- Keep rotor RPM within normal operating limits
- Roll out of turns no lower than 300 feet AGL
- Terminate within 100 feet of designated point
- Demonstrate smooth, coordinated control inputs throughout
Teaching Effectiveness: Use appropriate instructional techniques, provide timely feedback, recognize and correct student errors, and maintain positive learning environment while demonstrating maneuver proficiency.
Safety Management: Maintain situational awareness, use proper radio procedures, select appropriate practice areas, and demonstrate sound aeronautical decision-making throughout instruction.
Error Analysis: Accurately identify, explain causes of, and demonstrate corrections for common autorotation turn errors while maintaining instructional flow and aircraft control.