Steep Approach

Objective

By the completion of this lesson, the student will demonstrate the ability to perform a steep approach in accordance with FAA-S-ACS-15 Area of Operation V, Task D. The student will explain the principles of a stabilized steep approach, identify appropriate risk management techniques, and execute steep approaches maintaining a 10-15° approach angle while arriving at the termination point within ±4 feet.

Content

Stabilized Steep Approach Definition and Principles

A steep approach uses an approach angle of 10-15° (with 15° being the maximum) to clear obstacles or reach confined landing areas that normal approaches cannot access. Per the Helicopter Flying Handbook (FAA-H-8083-21B), steep approaches require precise power and attitude control to maintain the increased descent angle while managing closure rates.

The key principle is energy management - you’re trading altitude for distance at a steeper rate than normal, requiring more power to control descent rate and less power to arrest the descent at the bottom.

Approach Techniques and Applicability

Steep approaches are applicable when:

• Obstacles require clearance during approach (trees, wires, buildings)
• Landing areas are confined with limited approach paths
• Tactical or emergency situations demand rapid altitude loss over short distances
• Training for confined area operations

The technique differs from normal approaches by requiring:

• Higher power settings during descent to control rate
• More aggressive power application to arrest descent
• Steeper attitude changes
• Increased collective movements

Performance Data and Height-Velocity (H/V) Diagram

Per 14 CFR 27.87, the H/V diagram shows combinations of height and airspeed where safe autorotative landing may not be possible following engine failure. Steep approaches often require flight through the H/V diagram’s avoid area, making:

• Airspeed management critical
• Height selection important for obstacle clearance vs. autorotative capability
• Power margin assessment essential before entering avoid areas

Review your aircraft’s specific H/V diagram limitations and calculate power margins before attempting steep approaches.

Effects of Atmospheric Conditions

Density altitude significantly affects steep approach performance:

• Higher density altitude reduces available power margin
• Hot, humid, or high-altitude conditions limit steep approach capability
• Wind effects become more pronounced due to increased power requirements
• Temperature inversions can create sudden power requirement changes

Always calculate density altitude and available power before attempting steep approaches in marginal conditions.

Wind Correction Techniques

Wind correction during steep approaches requires:

• Headwind: Increases ground track angle, may require less power but increases avoid area exposure time
• Tailwind: Decreases ground track angle, requires more power, creates higher closure rates
• Crosswind: Requires constant drift correction using cyclic while maintaining approach angle with collective

The steeper approach angle makes wind effects more pronounced, requiring larger control inputs for correction.

Aircraft Performance and Limitations

Per your aircraft’s approved flight manual, steep approaches are limited by:

• Maximum power available (avoid exceeding torque/manifold pressure limits)
• Minimum airspeed for effective control authority
• Maximum approach angle (typically 15° per ACS standards)
• Center of gravity limits affecting flare capability

Risk Management

Approach Path Selection: Base selection on aircraft performance charts, obstacles, and wind. Always maintain escape route options and verify adequate power margin exists.

Wind Effects:

• Wind Direction: Plan approach into wind when possible; crosswinds complicate power and attitude management
• Windshear: Can cause sudden power requirement changes; abort if windshear suspected
• Turbulence/Wake Turbulence: Increases control difficulty and power fluctuations; avoid or delay approach in severe conditions

Contingency Planning:

• Rejected Landing: Pre-plan go-around power settings and attitude changes; practice escape maneuvers
• Powerplant Failure: Accept that autorotation options are limited during steep approaches; maintain minimum safe airspeeds when possible

Collision Hazards: Increased attention required due to steeper nose-down attitude limiting forward visibility; clear area before beginning approach.

Vortex Ring State (VRS): Risk increases with high power settings and steep descent rates. Maintain forward airspeed and avoid vertical descents.

Landing Surface Assessment: Steeper approaches limit surface evaluation time; complete thorough reconnaissance before beginning approach.

Aircraft Limitations: Monitor engine parameters closely; steep approaches stress powerplant and transmission components.

Distractions and Situational Awareness: The demanding nature of steep approaches increases workload; maintain disciplined scan and prioritize primary flight controls over secondary tasks.

Loss of Tail Rotor Effectiveness (LTE): High power requirements increase susceptibility to LTE; be prepared for rapid power reduction and altitude loss.

Degraded Visual Environment (DVE): Steep approaches in poor visibility are extremely hazardous; establish strict weather minimums and consider approach lighting requirements.

Schedule

Equipment

• Robinson R22/R44 or equivalent training helicopter
• Current weight and balance documentation
• Performance charts and H/V diagram for aircraft
• Helicopter Flying Handbook (FAA-H-8083-21B)
• Private Pilot Helicopter ACS (FAA-S-ACS-15)
• Aviation sectional chart for training area
• Flight computer or calculator for density altitude
• Appropriate checklists
• Kneeboard and pencil

Instructor Actions

1. Brief performance calculations demonstrating power margin requirements for steep approaches at current weight and density altitude
2. Explain H/V diagram implications and show how steep approaches affect autorotative capability
3. Demonstrate proper approach planning including wind assessment and termination point selection
4. Show complete steep approach from pattern altitude, verbalizing power and attitude changes throughout
5. Demonstrate go-around procedure from various points in the approach
6. Guide student through first steep approach attempt, providing control inputs as needed
7. Coach student on power management techniques, emphasizing anticipation over reaction
8. Point out visual cues for approach angle and closure rate assessment
9. Monitor engine parameters throughout lesson, teaching student to scan instruments during high-power operations
10. Debrief each approach attempt, identifying specific improvements needed
11. Demonstrate emergency procedures including simulated engine failure recognition and response
12. Evaluate student performance against ACS standards and provide specific feedback

Student Actions

1. Calculate density altitude and determine aircraft performance limitations for steep approaches
2. Plan approach path considering obstacles, wind, and termination point
3. Complete appropriate pre-landing checklist items
4. Make radio position reports as appropriate for traffic pattern or training area
5. Establish steep approach angle between 10-15° using attitude and power coordination
6. Maintain proper ground track with crosswind correction throughout approach
7. Control descent rate and closure speed with collective and throttle inputs
8. Monitor engine parameters and main rotor RPM throughout approach
9. Execute smooth flare and power application to arrive at termination point
10. Perform go-around when directed, applying appropriate power and attitude changes
11. Demonstrate rejected landing decision-making when approach becomes unstabilized
12. Verbalize risk assessment factors observed during each approach

Completion Standards

The lesson is complete when the student demonstrates competency in steep approach operations per FAA-S-ACS-15 PH.V.D by:

1. Knowledge: Explains stabilized steep approach principles, approach techniques, performance limitations, H/V diagram effects, atmospheric condition impacts, and wind correction requirements
2. Risk Management: Identifies and mitigates risks including approach path selection, wind effects, contingency planning, collision hazards, VRS, surface conditions, aircraft limitations, situational awareness, LTE, and DVE conditions
3. Skills:
   • Completes appropriate checklist items
   • Makes radio calls as appropriate to traffic situation
   • Considers wind direction, landing surface conditions, and obstacles in approach planning
   • Selects suitable termination point based on aircraft performance and conditions
   • Establishes and maintains steep approach angle between 10-15° (15° maximum per ACS)
   • Maintains proper ground track with effective crosswind correction
   • Maintains powerplant and Nr within normal operating limits throughout approach
   • Arrives at termination point (surface or stabilized hover) within ±4 feet of planned position
   • Uses appropriate runway incursion avoidance procedures when applicable

Performance must be consistent over multiple approach attempts with decreasing instructor intervention, demonstrating both technical proficiency and sound judgment in steep approach operations.