What is the consequence of having a surplus of power available while climbing?

Having a surplus of power available while climbing means that the helicopter's engine is providing more power than what is necessary to maintain a steady ascent. When there's excess power, the helicopter can achieve a climb rate that exceeds normal expectations, allowing for vertical climbs. This is because the additional power enables the helicopter to overcome not only its weight but also any drag present during the climb.

In typical operations, if a helicopter has enough power available, it can maintain a higher rate of climb and may potentially climb vertically under the right conditions. This capability is essential for performing operations that may require quick altitude gains, like avoiding obstacles or maintaining a specific flight profile.

The other choices do not accurately reflect the implications of having excess power during a climb. A helicopter still requires a certain amount of lift and thrust to climb effectively, and while increased power does enhance its climbing ability, it won't result in a horizontal trajectory or restricted speeds as suggested by the other options.