Approach and Landing with One Engine Inoperative (OEI) (simulated) (Multiengine Helicopter Only)

Objective

Upon completion of this lesson, the student will demonstrate the ability to safely execute an approach and landing with one engine inoperative (OEI) in a multiengine helicopter, meeting the performance standards outlined in FAA-S-ACS-15 PH.VIII.C. The student will identify engine failure indications, apply proper flight control techniques, maintain aircraft control throughout the approach, and execute a safe landing while managing single-engine performance limitations.

Content

Regulatory Requirements

Per 14 CFR 61.87(n), student pilots in multiengine helicopters must receive training in OEI procedures before solo flight. Commercial and ATP helicopter pilots must demonstrate proficiency in OEI operations per 14 CFR 61.127 and 61.161 respectively.

Multiengine Helicopter Systems Review

Twin-engine helicopters provide redundancy for continued flight following single-engine failure. However, performance is significantly degraded in OEI conditions. Key systems affected include:

• Power available vs. power required: OEI power curves shift dramatically, reducing available power envelope
• Height-velocity diagram limitations: Critical azimuth and avoid areas become more restrictive
• Anti-torque requirements: Increased power demand on remaining engine affects pedal control
• Hydraulic and electrical systems: May have reduced capacity or require manual reversion

Engine Failure Recognition

Engine failure indications vary by helicopter type but commonly include:

• Primary indicators: Torque decrease, ITT/EGT changes, rotor RPM decay
• Secondary indicators: Audio warnings, master caution lights, vibration changes
• Flight control feedback: Yaw tendency, collective pitch limitations, unusual control positions

Think of engine failure recognition like a doctor diagnosing symptoms—you need multiple indicators to confirm the problem, not just one.

OEI Flight Characteristics

Single-engine flight fundamentally changes helicopter performance:

• Reduced power margin: Available power may be insufficient for hover or climb
• Increased fuel consumption: Remaining engine operates at higher power settings
• Directional control challenges: Asymmetric thrust requires constant pedal pressure
• Autorotation considerations: Higher inertia and different CG may affect entry and recovery

Approach Planning Considerations

OEI approaches require modified planning:

• Approach angle: Typically steeper to maintain energy management options
• Approach speed: Higher speeds may be necessary to maintain translational lift benefits
• Landing site selection: Larger areas preferred due to reduced go-around capability
• Abort criteria: Predetermined decision points for autorotation entry if approach becomes unstable

Risk Management Items

Minimum Altitude Requirements: Per ACS risk management, this maneuver must be initiated at minimum 1000 feet AGL. This altitude provides adequate time for failure recognition, control recovery, and decision-making before committing to the approach.

Preflight Briefing Requirements: The instructor must conduct a thorough preflight briefing covering:

• Specific failure simulation method (power reduction, governor manipulation, etc.)
• Expected aircraft response and control inputs required
• Abort procedures and autorotation entry criteria
• Communication protocols during the maneuver
• Safety pilot responsibilities and positive exchange of controls

Multiengine Requirement: This task only applies when using a multiengine helicopter for practical test or training. Single-engine helicopters cannot demonstrate this specific emergency procedure.

Procedure Execution

1. Failure simulation: Instructor reduces power on one engine while maintaining safe flight parameters
2. Recognition and analysis: Student identifies failure indications and confirms engine status
3. Initial response: Lower collective to maintain rotor RPM, adjust anti-torque pedals for coordination
4. Performance assessment: Determine available power and establish appropriate approach profile
5. Approach execution: Maintain coordinated flight while managing energy and approach path
6. Landing execution: Touch down with minimal forward speed and maximum control margin

Performance Limitations

OEI performance varies significantly with:

• Density altitude: Higher altitudes reduce available power margin
• Gross weight: Heavier aircraft may be unable to maintain level flight OEI
• Configuration: Landing gear and external loads increase power requirements
• Environmental factors: Wind, turbulence, and obstacles affect approach planning

Schedule

Equipment

• Aircraft: Multiengine helicopter (twin-engine configuration required)
• References:
  • FAA-H-8083-21B Helicopter Flying Handbook (Chapter 11)
  • Aircraft Flight Manual/Pilot’s Operating Handbook
  • FAA-S-ACS-15 Private Pilot Helicopter ACS
• Materials: Approach plates, airport/facility directory, performance charts
• Visual Aids: Height-velocity diagram, power available/required charts
• Safety Equipment: Standard flight equipment, emergency procedures checklist

Instructor Actions

1. Conduct comprehensive preflight briefing covering failure simulation method, expected aircraft response, safety protocols, and abort criteria as required by ACS risk management standards
2. Demonstrate proper engine failure recognition techniques using realistic failure scenarios
3. Show correct initial response procedures: collective lowering, pedal adjustment, and rotor RPM maintenance
4. Demonstrate performance assessment techniques to determine OEI capabilities and limitations
5. Execute complete OEI approach showing proper energy management, approach angle selection, and directional control
6. Illustrate decision-making process for approach continuation versus autorotation entry
7. Guide student through practice approaches, providing immediate feedback on control inputs and flight path management
8. Simulate various failure scenarios to build student recognition and response skills
9. Emphasize safety margins and conservative decision-making throughout OEI operations
10. Debrief each approach focusing on performance standards and areas for improvement

Student Actions

1. Participate actively in preflight briefing, asking clarification questions about procedures and safety protocols
2. Demonstrate proper pre-maneuver checks including power available confirmation and emergency procedure review
3. Recognize simulated engine failure indications within 3 seconds of occurrence
4. Execute immediate response procedures: lower collective to maintain rotor RPM, apply appropriate anti-torque pedal pressure
5. Assess remaining engine performance and determine OEI flight envelope limitations
6. Plan and execute OEI approach maintaining coordinated flight and appropriate approach angle
7. Manage energy throughout approach, maintaining safe airspeeds while preparing for landing
8. Execute landing with minimal forward speed and maximum control authority margin
9. Demonstrate proper abort procedures if approach becomes unstable or unsafe
10. Complete post-maneuver analysis identifying key decision points and performance factors

Completion Standards

The student demonstrates satisfactory performance when able to:

1. Recognition (FAA-S-ACS-15 PH.VIII.C): Recognize simulated engine failure within 3 seconds and identify specific failure indications correctly
2. Initial Response: Execute immediate action items maintaining rotor RPM within normal operating range and preventing yaw excursions greater than 10 degrees
3. Performance Assessment: Correctly determine OEI performance limitations and establish appropriate approach profile within 30 seconds of failure recognition
4. Approach Management: Maintain coordinated flight throughout approach with heading control within ±10 degrees and airspeed appropriate for aircraft configuration
5. Energy Management: Demonstrate proper collective and cyclic coordination maintaining safe approach angle without excessive sink rates or airspeeds
6. Landing Execution: Complete safe touchdown with forward groundspeed less than 10 knots and maintain directional control throughout rollout
7. Decision Making: Demonstrate appropriate abort decision criteria and execute autorotation entry if approach parameters exceed safe limits
8. Risk Management: Identify and mitigate risks associated with OEI operations including performance limitations, environmental factors, and emergency landing site selection
9. Communication: Maintain clear communication with instructor throughout maneuver and demonstrate proper emergency radio procedures when applicable
10. Safety Margins: Maintain conservative approach to OEI operations with adequate power reserves and abort options throughout approach phase