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Given the following information, calculate the Total Rotor Thrust during a level turn:

Helicopter mass: 2 000 kg
TAS: 120 kt
Bank angle: 60°

  • A

    80 000 N

  • B

    20 000 N

  • C

    56 000 N

  • D

    40 000 N

1. The Total Rotor Thrust (TRT) is an aerodynamic force measured in Newton and opposes the Weight (measured in Newton as well). So, convert the mass (kg) into weight (N):

  • 2 000 kg x 9.81 m/s2 = 19 620 N

2. During a turn, the TRT is split into two components:

  • a horizontal (acting as a centripetal force): TRT x sin Bank angle, and
  • a vertical (opposing the weight): TRT x cos Bank angle.

3. During a level turn, the vertical component of TRT (TRT x cos Bank angle) is equal to the Weight.

4. The TRT required to maintain a turn is found dividing the Weight by the cosine of the bank angle. So, the Total Rotor Thrust in a turning manoeuvre is:

  • TRT = Weight / cos Bank angle = 19 620 N / cos 60° ≈ 40 000 Newton.

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