14 / 20

What needs to be observed in conjunction with flying above mountainous terrain?

  • A

    Unexpected changes in weather and turbulence.

  • B

    Unexpected overspeed faults and vibrations.

  • C

    Carburettor icing in piston engines.

  • D

    Icing conditions over the predicted freezing level.

The helicopter's ability to transit through, manoeuvre, land and take off from hilly or mountainous terrain is one of the most demanding aspects of helicopter operations. Pilots at some stage are likely to experience this challenging environment and require an understanding of the basic principles, threats, errors and the possible undesirable aircraft states, in order to operate safely. Whilst the terrain can vary in its topography, hazards, elevation and prevalent weather, the same basic techniques should be utilised. Flying in hilly or mountainous terrain is particularly demanding and has resulted in a number of helicopter accidents.

An awareness of the wind speed and direction is critical in the hills and mountainous terrain because it follows the surface.

On a windward slope turbulence rarely exists and the resulting up-draughts can be beneficial in producing lift and therefore requiring less power to manoeuvre. As a result the windward slope with up-draughts is preferable to operate in whenever possible.

On a leeward slope there is generally turbulence and down-draughts that can make flight hazardous and should be avoided.

Also, mountainous areas are prone to rapidly changing weather conditions. These changes can include sudden storms, high winds, and severe turbulence due to the rugged topography.

Your Notes (not visible to others)



This question has appeared on the real examination, you can find the related countries below.

  • Austro Control