VIII. Emergency Operations – Task C. Approach and Landing with One Engine Inoperative (OEI) (simulated) (Multiengine Helicopter Only) (Operational Requirements)

Objective

The commercial helicopter pilot student will demonstrate safe planning, execution, and completion of an approach and landing with one engine inoperative (simulated) in a multiengine helicopter, initiating the maneuver at a minimum altitude of 1,000 feet AGL and maintaining aircraft control within commercial pilot ACS tolerances throughout the approach and landing sequence, per ACS task CH.XIV.E.

Content

Regulatory Foundation

14 CFR §61.63(c) — Type rating requirements for multiengine helicopters weighing more than 12,500 pounds. While not all multiengine helicopters require type ratings, commercial pilots must understand these distinctions and the aircraft-specific limitations in the approved rotorcraft flight manual (RFM).

14 CFR §91.119 — Minimum safe altitudes. The 1,000-foot AGL minimum for initiating this maneuver provides adequate altitude for recovery from simulated engine failures while complying with general operating rules. This protects both the flight crew and persons and property on the surface.

14 CFR §91.13 — Careless or reckless operation. Simulating engine failures without proper planning, briefing, and altitude management constitutes careless operation. Commercial pilots must demonstrate professional risk management in training scenarios that will prepare them for actual emergencies.

Multiengine Helicopter Performance Theory

Multiengine helicopters are designed with engine-out capability, but this capability exists within specific performance envelopes defined by the manufacturer. Unlike fixed-wing multiengine aircraft that can often maintain level flight with one engine inoperative, most multiengine helicopters experience performance degradation requiring immediate pilot response.

Critical Performance Parameters:

• One-Engine-Inoperative (OEI) Power Available — The remaining engine must produce sufficient power to maintain rotor RPM and control both vertical and horizontal flight path. This power requirement increases with density altitude, gross weight, and maneuvering flight.

• Height-Velocity Diagram — While not the primary focus of this maneuver, commercial pilots must understand that OEI operations often require operating within previously-avoided portions of the H-V diagram. The RFM will specify OEI height-velocity curves that differ from the all-engines-operating curves.

• Increased Power Requirements — The operating engine must overcome the drag of the failed engine, increased anti-torque requirements, and any asymmetric thrust or drag effects. In helicopters with wing-mounted engines (like the CH-47), asymmetric thrust creates control challenges absent in centerline-thrust helicopters.

• Yaw Control Considerations — Loss of one engine creates an imbalance that must be countered with tail rotor thrust or other anti-torque devices. This increases power requirements on the operating engine and may limit available power for altitude or airspeed control.

Preflight Briefing Requirements

The ACS explicitly requires a preflight briefing before simulating any powerplant failure. This briefing protects both instructor and student and establishes clear communication protocols. Ryan Dale’s approach: “Brief it like your life depends on it, because someday it might.”

Required Briefing Elements:

1. Altitude Parameters — Minimum 1,000 feet AGL for initiation; specific altitude where simulation begins; minimum recovery altitude (typically 500 feet AGL)

2. Simulation Method — How the instructor will simulate the failure (throttle reduction, simulated governor failure, verbal callout); which engine will be “failed”

3. Expected Student Actions — Immediate recognition of failure; appropriate control inputs; callouts; decision-making process for approach continuation vs. go-around

4. Instructor Intervention Criteria — Conditions under which instructor will terminate the maneuver (altitude limits, airspeed limits, unsafe control responses, traffic conflicts)

5. Communication Protocol — Standard callouts (“Simulating left engine failure NOW”); termination phrases (“My controls” or “Recover”); acknowledgment requirements

6. Abort Criteria — Student must understand when to discontinue the approach and execute an OEI go-around; emphasis that this is a normal professional decision, not a failure

Approach and Landing Procedures with OEI

Initial Recognition and Response:

When engine failure is simulated (or occurs), the pilot flying must immediately:

1. Maintain rotor RPM within operating limits through collective reduction if necessary
2. Apply appropriate anti-torque pedal to counter yaw
3. Establish appropriate airspeed for the approach (typically Vy or manufacturer-recommended OEI approach speed)
4. Assess aircraft performance capability with remaining engine

Think of the initial response as “fly the helicopter first, diagnose second.” Unlike private pilot training where we emphasize emergency procedures checklists, commercial OEI operations demand immediate aircraft control followed by systematic performance assessment.

Performance Assessment:

Before committing to an approach, the commercial pilot must evaluate:

• Can the operating engine maintain level flight at current weight and density altitude?
• Is sufficient power available for a controlled deceleration and landing?
• Does the selected landing area provide adequate obstacle clearance given degraded climb performance?
• Are winds favorable for the approach direction required by the emergency?

If performance is insufficient, the pilot must immediately transition to an OEI autorotation or select an alternate landing area within performance capabilities.

Approach Profile:

Unlike normal approaches where pilots have flexibility in profile selection, OEI approaches demand precision planning:

• Steeper Approach Angles — Reduced power available often necessitates steeper approaches to maintain energy management; typical OEI approaches are 10-12° vs. 8-10° for normal operations

• Higher Approach Speeds — Manufacturer-recommended OEI approach speeds (often Vy +5-10 knots) provide better control response and energy management; these speeds are higher than private pilot training emphasized

• Constant Angle vs. Constant Altitude — OEI approaches favor constant-angle descents over stepdown approaches; maintaining a steady descent path reduces power fluctuations and provides predictable performance

• Landing Area Selection — Commercial pilots must select areas providing adequate run-on distance; hovering capability may be severely limited or impossible at current weight

Control Technique:

OEI approaches require precise coordination:

• Collective Management — Small, smooth inputs; avoid rapid power changes that could exceed operating engine limits or cause rotor RPM excursions
• Anti-torque Control — Anticipate pedal requirements during power changes; operating engine produces different torque at different power settings, requiring continuous pedal adjustment
• Cyclic Control — Maintain precise airspeed control; speed deviations require power corrections that may not be available
• Trim Coordination — All control inputs must be coordinated; attempting to “muscle” the helicopter creates excessive control loads and degrades precision

Final Approach and Landing:

As the helicopter descends through 200 feet AGL:

• Confirm landing area is clear and suitable for current performance state
• Plan for run-on landing if hover power is unavailable
• Establish stabilized approach parameters (airspeed ±5 knots, descent rate steady, rotor RPM within limits)
• Begin deceleration based on performance available — if insufficient power for hover, plan touchdown at 10-20 knots groundspeed
• Execute touchdown with minimal vertical velocity (less than 200 feet per minute)
• After touchdown, smoothly reduce collective to full down, neutralize cyclic, maintain heading with pedals

Go-Around Considerations:

Commercial pilots must recognize that OEI go-arounds are high-risk maneuvers requiring careful performance analysis. If go-around becomes necessary:

• Recognize the need early (before descending below 300 feet AGL in most helicopters)
• Smoothly apply available power while maintaining rotor RPM limits
• Accelerate to Vy while minimizing altitude loss
• Assess climb capability; if insufficient, transition to OEI autorotation to suitable landing area

Think of the go-around decision like this: “The go-around is always an option until it’s not. Your job is to recognize that transition point before you cross it.”

Risk Management Elements

Altitude Management:

The 1,000-foot AGL minimum exists for concrete safety reasons:

• Provides adequate altitude for failure recognition and initial response
• Allows recovery to normal flight if student response is inappropriate
• Maintains compliance with §91.119 minimum safe altitudes
• Permits safe transition to autorotation if simulated failure becomes actual emergency

Commercial pilots must internalize that this is a minimum — in many helicopters, in high density altitude conditions, or with less experienced pilots, 1,500-2,000 feet AGL provides better safety margins.

Preflight Briefing as Risk Mitigation:

The briefing is not administrative overhead — it’s essential risk management. Clear communication prevents:

• Startle response when instructor simulates failure
• Confusion about recovery procedures
• Unsafe continuation of maneuver below minimum altitudes
• Misunderstanding about who has control authority

Ryan Dale’s perspective: “I’ve never heard a NTSB report that said ‘they briefed too thoroughly.’ I’ve read dozens where lack of briefing killed people.”

Aircraft Limitations Awareness:

Each multiengine helicopter has specific OEI limitations in the RFM:

• Maximum OEI power settings (typically time-limited to 2.5 or 5 minutes)
• OEI airspeed limitations
• OEI altitude limitations
• Configuration requirements (landing gear position, doors, etc.)

Exceeding these limitations during training creates actual emergencies from simulated ones. Commercial pilots must know these numbers cold before attempting OEI operations.

Environmental Considerations:

• Density Altitude — High density altitude dramatically reduces OEI performance; maneuvers planned for sea level may be impossible at 5,000 feet elevation
• Wind Conditions — Tailwinds on approach increase groundspeed and required landing distance; crosswinds require additional anti-torque power that may not be available
• Surface Conditions — OEI landings may require run-on touchdowns; soft surfaces, slopes, or obstacles present additional hazards
• Traffic Pattern — Other traffic may not anticipate steeper, faster approach profile; vigilant visual clearing and radio communication required

Personal Risk Factors:

Commercial pilots must honestly assess:

• Fatigue level — OEI operations demand peak mental and physical performance
• Proficiency — Is this the first OEI approach in 6 months? Consider practice at altitude before attempting to landing
• Aircraft familiarity — Do you know this helicopter’s OEI characteristics intimately?
• Weather — Marginal VFR reduces visual references needed for precise control

Common Errors and Corrections

Error: Inadequate preflight briefing or skipping briefing entirely

This error stems from overconfidence or rushing. Correction: Make the briefing a checklist item. No briefing = no maneuver, period.

Error: Initiating below 1,000 feet AGL

Students accustomed to private pilot training may initiate at lower altitudes. Correction: Brief specific initiation altitude and verify altimeter reading before beginning. Instructor must monitor and prevent initiation below minimums.

Error: Fixation on engine gauges instead of flight instruments

Students may stare at the “failed” engine instead of flying the aircraft. Correction: “Your primary job is flying, not diagnosing. Quick glance to confirm, eyes back outside and on flight instruments.”

Error: Excessive collective reduction causing rotor RPM decay

Overreaction to simulated failure. Correction: “The engine didn’t fail — one did. You still have power. Adjust collective smoothly based on actual aircraft performance, not fear.”

Error: Attempting to hover with insufficient power

Students may try to terminate in hover when performance doesn’t support it. Correction: “Know your numbers. If the math says you can’t hover, plan for a run-on landing from 200 feet up, not at 10 feet when you’re out of options.”

Error: Continuing approach below safe abort altitude when go-around is needed

Commercial pilots must develop decision-making discipline. Correction: “The approach is optional. The landing is negotiable. Turning a marginal situation into an accident is unacceptable. If it doesn’t feel right at 300 feet, go around or autorotate to a safe area.”

Error: Inadequate anti-torque compensation during power changes

Students may allow heading deviations during approach power adjustments. Correction: “Every collective movement is a three-axis event. Anticipate the yaw, lead with the pedal, maintain heading within 5 degrees throughout.”

Schedule

Equipment

Required Aircraft Equipment

• Multiengine helicopter (tandem or side-by-side engine configuration)
• Serviceable dual controls
• All required instruments operational per 14 CFR §91.205
• Current and accurate weight and balance data
• Functional intercom system for clear CFI-student communication

Required Documents and References

• FAA-S-ACS-16 Commercial Pilot Helicopter Airman Certification Standards (current edition)
• FAA-H-8083-21B Rotorcraft Flying Handbook
• Aircraft-specific Rotorcraft Flight Manual (RFM) with OEI performance charts
• Aircraft-specific OEI procedures checklist or quick reference guide
• Airport/Facility Directory for practice area
• Current sectional chart
• Student pilot logbook

Teaching Aids and Materials

• Whiteboard or notepad for briefing diagrams
• OEI performance chart examples from RFM (laminated or photocopied)
• Height-Velocity diagram showing OEI vs. normal operations curves
• Model helicopter or diagram showing engine locations and torque effects
• Checklist of preflight briefing required elements
• Sample OEI approach profile diagram (overhead view and side view)
• Video recording device (optional, for post-flight review)

Personal Equipment

• Current pilot certificates and medical certificates (CFI and student)
• Headset with operational microphone for both CFI and student
• Sunglasses and sun protection (OEI approaches require extended practice at altitude)
• Kneeboards for both CFI and student with approach data cards

Instructor Actions

1. Conduct thorough preflight ground discussion covering multiengine helicopter performance theory, OEI power limitations from the RFM, regulatory requirements for the maneuver (1,000 feet AGL minimum, preflight briefing requirement), and learning objectives for the lesson.

2. Review aircraft-specific OEI performance data with the student using actual RFM charts for current weight, density altitude, and wind conditions; calculate expected power available with one engine inoperative; determine if hover will be possible or if run-on landing is required.

3. Demonstrate proper preflight briefing technique by conducting the actual pre-maneuver briefing as a teaching example, explaining each required element (altitude parameters, simulation method, expected actions, intervention criteria, communication protocol, abort criteria) and why it matters for safety.

4. Verify student understanding by having student explain back the briefing elements, state the minimum initiation altitude, describe the simulation method to be used, and identify personal abort criteria for the approach.

5. Conduct standard aircraft preflight and brief the student to pay particular attention to engine instrument functionality, anti-torque system condition, and any RFM-required configuration items for OEI operations.

6. Perform normal takeoff and departure to the practice area, maintaining student proficiency in basic helicopter operations while explaining the day’s practice area selection criteria (altitude above terrain, suitable landing areas, traffic considerations).

7. Establish the aircraft at 1,500 feet AGL in the practice area and complete clearing turns; explain this provides 500 feet above the ACS minimum for demonstration purposes and additional safety margin.

8. Conduct instructor demonstration of complete OEI approach from initiation through landing, narrating all actions: “Simulating left engine failure now. I’m maintaining rotor RPM with slight collective reduction. Applying right pedal to counter yaw. Checking engine instruments on the operating engine. Airspeed coming back to 60 knots, our manufacturer-recommended OEI approach speed for this weight. I’m establishing a 10-degree approach angle toward that clear area ahead. Throughout the approach I’m making small collective adjustments to maintain 60 knots and rotor RPM in the green arc. At 200 feet I’m beginning my deceleration. Our performance charts showed we won’t have hover power, so I’m planning a run-on landing at about 15 knots. I’m keeping the approach stabilized—airspeed within 5 knots, heading within 5 degrees, descent rate steady. At 50 feet I’m in landing attitude. Touchdown with minimal sink rate, collective down smoothly, holding heading with pedals.”

9. Debrief the demonstration immediately after landing, highlighting key decision points, control inputs, and performance monitoring; ask student to identify what they observed in the CFI’s technique.

10. Position aircraft for student’s first attempt by climbing back to 1,500 feet AGL and completing clearing turns; remind student of the preflight briefing elements and confirm they are ready to begin.

11. Initiate the simulated engine failure at 1,500 feet AGL using the briefed method (typically smooth throttle reduction on one engine while stating “Simulating left engine failure now”); monitor student’s immediate response to failure recognition.

12. Observe and coach during the student’s first attempt, providing real-time guidance for significant deviations: “Watch your rotor RPM,” “More right pedal,” “Airspeed is 10 knots fast, let it come back smoothly,” but allow the student to work through the maneuver with minimal intervention.

13. Take control if safety margins are exceeded using the briefed command (“My controls”) if the student descends below 500 feet AGL without establishing safe approach parameters, allows rotor RPM to approach limits, or creates an unsafe condition with other traffic or obstacles.

14. Conduct immediate post-landing debrief after the first attempt while details are fresh; identify two things done well and one specific item to improve on the next attempt; avoid overloading with excessive critique.

15. Reset for second attempt by repositioning to 1,500 feet AGL; ask student to verbalize their plan for the next approach, incorporating the improvement item discussed.

16. Initiate second simulated failure and observe for improvement in the targeted area; continue monitoring overall performance and safety.

17. Provide progressive coaching on subsequent attempts, reducing verbal intervention as student demonstrates proficiency; transition from directive coaching (“Add right pedal now”) to questioning coaching (“What does your heading need?”).

18. Execute third and final practice attempt with minimal CFI intervention, allowing student to demonstrate independent proficiency; this attempt should approximate practical test conditions.

19. Conduct comprehensive debrief after the final practice, comparing student performance to ACS completion standards; specifically address: initiation altitude compliance, approach stabilization, control precision, decision-making quality, and emergency procedure execution.

20. Return to airport using normal procedures while discussing how OEI approach practice integrates with commercial pilot privileges and responsibilities; reinforce that this is a skill required for safe multiengine operations, not just a test maneuver.

21. Complete post-flight documentation including detailed logbook entry describing the maneuver practiced, student performance level, and endorsement if the student meets completion standards for this task; provide written feedback on areas requiring additional practice before practical test.

Student Actions

1. Actively participate in preflight ground discussion by asking questions about OEI performance concepts, reviewing RFM performance charts, and relating the maneuver to previous multiengine training experience.

2. Calculate OEI performance for the current flight conditions using RFM charts; determine expected power available with one engine inoperative; identify whether hover capability exists or run-on landing will be required.

3. Participate in the preflight briefing as the pilot-in-command by confirming understanding of each briefing element, asking clarification questions, and verbalizing personal abort criteria for the approach.

4. Conduct thorough aircraft preflight with particular attention to engine systems, anti-torque components, and required instruments; report any discrepancies to the instructor.

5. Perform normal takeoff and departure to the practice area while maintaining commercial pilot performance standards (altitude ±100 feet, heading ±5 degrees, airspeed ±5 knots).

6. Observe instructor demonstration carefully, noting the timing and magnitude of control inputs, the approach profile selected, decision points during the approach, and control technique during landing.

7. Ask questions immediately after the demonstration about any observed techniques or decisions that were unclear; verbalize the key steps of the maneuver back to the instructor.

8. Position aircraft at 1,500 feet AGL and complete clearing turns; perform pre-maneuver checks and confirm readiness to begin.

9. Respond immediately to simulated engine failure when instructor initiates the simulation: identify the failure, maintain rotor RPM through appropriate collective adjustment, apply anti-torque pedal to counter yaw, and transition to manufacturer-recommended OEI approach airspeed.

10. Establish stabilized OEI approach by selecting appropriate landing area within aircraft’s performance capability, establishing constant-angle descent at recommended approach speed, monitoring engine instruments on operating engine, and maintaining rotor RPM within normal operating range.

11. Maintain precise aircraft control throughout the approach: heading ±5 degrees, airspeed ±5 knots, rotor RPM within green arc, coordinated flight with proper anti-torque pedal application.

12. Make go/no-go decision no later than 300 feet AGL based on approach stabilization and aircraft performance; if approach is not stabilized or performance is insufficient, execute OEI go-around or transition to autorotation to suitable landing area.

13. Execute approach termination appropriate to available performance: if hover power is available, decelerate to hover over intended landing point; if hover power is not available, plan and execute run-on landing at minimum safe groundspeed (typically 10-20 knots).

14. Perform touchdown with minimal vertical velocity (less than 200 feet per minute), smooth collective reduction after touchdown, positive directional control throughout landing roll if applicable, and safe shutdown procedures.

15. Participate in post-landing debrief by self-assessing performance against ACS standards, identifying personal errors and successful techniques, asking specific questions about observed performance deficiencies.

16. Verbalize improvement plan before second attempt based on debrief feedback; state specific control technique or decision point to focus on during next practice.

17. Execute subsequent practice attempts with progressive improvement in targeted areas; demonstrate learning and adaptation based on previous attempt feedback.

18. Demonstrate independent proficiency on final practice attempt by executing the entire maneuver with minimal instructor intervention; show decision-making capability appropriate to commercial pilot privileges.

19. Conduct self-assessment after final practice by comparing own performance to ACS completion standards; honestly identify areas meeting standards and areas requiring additional practice.

20. Complete post-flight procedures and participate in comprehensive debrief; accept feedback professionally and develop personal practice plan for continued proficiency development.

Completion Standards

The student demonstrates understanding of multiengine helicopter OEI operations and performs an approach and landing with one engine inoperative (simulated) in accordance with ACS task CH.XIV.E and the aircraft’s operating limitations. Specifically, the student:

Knowledge Standards:

• Explains the regulatory requirement for 1,000 feet AGL minimum initiation altitude per the ACS and relates this to 14 CFR §91.119 and §91.13
• Describes all required elements of the preflight briefing and articulates why each element is essential for safe conduct of the maneuver
• Accurately interprets the aircraft’s RFM OEI performance charts for current weight and density altitude conditions
• Identifies aircraft-specific OEI limitations including maximum power settings, time limitations, airspeed restrictions, and configuration requirements
• Explains the differences between OEI approach procedures and normal approach procedures, including steeper approach angles, higher approach speeds, and modified landing techniques
• Describes appropriate go-around decision criteria and recognizes when aircraft performance is insufficient to continue the approach safely

Risk Management Standards:

• Initiates the OEI approach at a minimum altitude of 1,000 feet AGL as required by the ACS
• Completes a comprehensive preflight briefing covering all required elements before attempting the maneuver
• Demonstrates awareness of aircraft performance limitations and selects landing areas within OEI performance capability
• Maintains proper altitude awareness throughout the maneuver and does not descend below 500 feet AGL without establishing a stabilized approach
• Recognizes environmental factors affecting OEI performance (density altitude, wind, surface conditions) and adjusts technique accordingly
• Makes timely go/no-go decisions based on approach stabilization and available performance, executing go-around or alternative landing before reaching committed position

Skill Standards:

• Initiates the OEI approach at a minimum of 1,000 feet AGL in compliance with ACS requirements
• Recognizes simulated engine failure immediately and applies appropriate control inputs within 3 seconds: rotor RPM maintenance, anti-torque pedal application, airspeed transition
• Establishes and maintains manufacturer-recommended OEI approach airspeed ±5 knots throughout the approach
• Maintains heading ±5 degrees during approach with coordinated flight and appropriate anti-torque pedal usage
• Maintains rotor RPM within normal operating range (green arc) throughout the approach and landing sequence
• Establishes a stabilized constant-angle approach appropriate to available OEI performance
• Executes approach termination appropriate to aircraft performance: hover with minimal drift if power is available, or controlled run-on landing at 10-20 knots groundspeed if hover power is unavailable
• Touches down with vertical velocity less than 200 feet per minute and maintains positive aircraft control throughout landing
• Completes landing roll (if applicable) on intended heading ±5 degrees with smooth collective reduction and coordinated pedal inputs
• Demonstrates smooth, coordinated control throughout the maneuver without abrupt or excessive control inputs
• Maintains situational awareness and communicates intentions clearly using appropriate phraseology
• Operates within all aircraft limitations as specified in the RFM, including OEI power limits and time restrictions

Overall Performance:

The successful student completes the approach and landing with one engine inoperative (simulated) in a manner that demonstrates commercial pilot-level proficiency: precise aircraft control, professional decision-making, thorough risk management, and comprehensive understanding of multiengine helicopter OEI operations. Performance meets or exceeds all standards specified in ACS task CH.XIV.E and prepares the student for safe execution of this emergency procedure in actual operations.