There is many wrong answers in this thread but I want to address one that any rated helicopter pilot should be able to answer (which judging by the answers in this thread may be not as true as I’m hoping) and that is:

YOU CANNOT GET VORTEX RING STATE IN AN AUTOROTATION

The three things you need for VRS or “Settling with Power” (FAA definition) are:

Rate of descent greater than 300fpm Speed less than ETL POWER APPLIED

Obviously if the engine has quit you cannot have power applied.

That being said, you do still have energy stored in the helicopter in the form of potential energy (in altitude above ground level) and kinetic energy (in the helicopters airspeed). Kinetic energy increases exponentially with airspeed ie. if you double your airspeed (ex. 30 to 60 kts) you triple the amount of kinetic energy you can use to maintain your rotor RPM in the flare (that you will need a lot of to arrest the rate of descent and forward airspeed prior to touching down)

If you have no airspeed you have a higher rate of descent in the auto and less energy to arrest that rate of descent with prior to landing.

Answers to these questions and more can be found in the Helicopter Flying Handbook which is free to download from the FAA website!

Cheers

-FAA RW Commercial Pilot and CFI-I

There are many wrong answers in this thread but I want to address one that any rated helicopter pilot should be able to answer (which judging by the answers in this thread may be not as true as I’m hoping) and that is:

YOU CANNOT GET VORTEX RING STATE IN AN AUTOROTATION

The three things you need for VRS or “Settling with Power” (FAA definition) are:

• Rate of descent greater than 300fpm
• Speed less than ETL
• POWER APPLIED

Obviously if the engine has quit you cannot have power applied.

That being said, you do still have energy stored in the helicopter in the form of potential energy (in altitude above ground level) and kinetic energy (in the helicopters airspeed). Kinetic energy increases exponentially with airspeed i.e. if you double your airspeed (ex. 30 to 60 kts) you triple the amount of kinetic energy you can use to maintain your rotor RPM in the flare (that you will need a lot of to arrest the rate of descent and forward airspeed prior to touching down)

If you have no airspeed you have a higher rate of descent in the auto and less energy to arrest that rate of descent with prior to landing.

Answers to these questions and more can be found in the Helicopter Flying Handbook which is free to download from the FAA website!

-FAA RW Commercial Pilot and CFI-I