Takeoff and Landing Performance[PDF]

Introduction

Helicopters have the unique ability to take-off and land almost anywhere. It is the responsibility of the pilot to determine if a safe take-off and landing is possible and the availability of sufficient power.

The calculation process for single piston engine helicopters is much more easier than multi-engines.

In this chapter, the most common and basic methods are explained to create a general understanding.

Take-off

Basic take-off performance calculation of a helicopter can be done in three steps.

Step-1: Cross-check actual and maximum allowable IGE/OGE gross weight.

Actual gross weight should always be lower than maximum allowable IGE gross weight.

If out of ground effect hover is expected, actual gross weight should be lower than maximum allowable OGE gross weight.

Step-2: Cross-check predicted IGE/OGE hover torque and maximum torque available.

Predicted IGE hover torque should always be lower than maximum torque available.

If out of ground effect hover is expected, predicted OGE hover torque should be lower than maximum torque available.

Step-3: Cross-check actual IGE hover torque and predicted IGE hover torque(in flight).

If actual hover torque is more than predicted hover torque, cross-check your performance calculations.

When the Running/Rolling Takeoff procedure is used, a safe take-off can be achieved even with less power required for IGE hover.

Landing

Landing calculations are not much different than take-off calculations. The same procedure is applied for the arrival airport conditions.

Step-1: Cross-check actual and maximum allowable IGE/OGE gross weight for landing aerodrome.

Actual gross weight should always be lower than maximum allowable IGE gross weight.

If out of ground effect hover is expected, actual gross weight should be lower than maximum allowable OGE gross weight.

Step-2: Cross-check predicted IGE/OGE hover torque and maximum torque available for landing aerodrome.

Predicted IGE hover torque should always be lower than maximum torque available.

If out of ground effect hover is expected, predicted OGE hover torque should be lower than maximum torque available.

Step-3: Apply a power check procedure in straight-and level for maximum torque available.

If maximum torque available could not be established, cross-check your performance calculations.

When the Running/Rolling landing procedure is used, a landing-can be achieved even with less power required for IGE hover.

Power Checks

Conditions at take-off and landing sites may differ from what has been used for rotorcraft flight manual performance calculations. The power check will tell you if you have sufficient power to do the approach or take-off.

Power Check Prior to Take-Off

The initial power check prior to take-off is executed in hover. The calculated IGE hover power is compared with real hover power and the margin between calculated and real power is evaluated by pilots.

Power Check Prior to landing

Prior landing power check is executed in straight and level flight. Smooth collective is applied until reaching maximum power and the margin between calculated and real maximum power is evaluated by pilots.

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See also

• Factors affecting Helicopter performance
• Hovering Performance
• Climb Performance
• Cruise Performance

Reference

• None

Author

• VID 522050 - <Creation>