Can a helicopter climb vertically?

No. You’re going to be taking off a lot like an airplane might, with a bunch of forward movement before you start climbing. This is why a “normal takeoff” for a helicopter climbs out after gaining airspeed — instead of climbing straight up. It’s for safety reasons.

What is the purpose of the autorotation maneuver in a helicopter?

It is analogous to the gliding flight of a fixed-wing aircraft. The most common use of autorotation in helicopters is to safely land the aircraft in the event of an engine failure or tail-rotor failure. It is a common emergency procedure taught to helicopter pilots as part of their training.

How fast can a helicopter go straight up?

An average helicopter can reach a top speed of somewhere between 130 and 140 knots, which comes out to about 160 mph.

What affects helicopter performance?

The three major factors that affect performance are density altitude, weight, and wind. The density of the air directly affects the performance of the helicopter. As the density of the air increases, engine power output, rotor efficiency, and aerodynamic lift all increase.

What is autorotation in a spin?

For fixed-wing aircraft, autorotation is the tendency of an aircraft in or near a stall to roll spontaneously to the right or left, leading to a spin (a state of continuous autorotation).

Why is vertical autorotation not recommended?

There are three good reasons to avoid Vertical Autorotation. First, Vertical Autorotation is way more likely to lead to a Vortex Ring condition where the air exiting the rotor disk gets recirculated back through the rotor disk.

Can helicopters autorotate back to Earth?

Helicopters can autorotate back to earth in case of emergency. The FAA recommends a flight profile similar to the following procedure: Notice that in section (2) there is forward speed: vertical autorotation is not recommended. Why is that?

What is the effect of forward velocity on autorotation?

The effect of forward velocity on auto rotational rate of descent is depicted in a graph in this book: Going back to vertical autorotation: the vertical upward airstream needs to go through the rotor fast enough to reach the windmilling state, so that lift is created by decelerating the air passing through it.

How to control the speed of the rotors during autorotation?

During autorotation, forward speed is used to control rotor head speed. In auto, the engine is disconnected (in the case of tail rotor failure) or just plain dead, so it can’t be used to control rotor speed.