Welcome Guest. Sign in or Signup

3 Answers

Helicopter torque

Asked by: 972 views ,
Aerodynamics, Helicopter

In terms of a hover auto why do we need to apply right pedal when rolling off throttle? I understand torque effect but if we remove it by rolling off throttle why would we begin to spin in the direction of the rotor? What force is this demonstrating? Thanks from r the insight

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

3 Answers

  1. Best Answer

    Kris Kortokrax on Apr 24, 2017

    There is a balance between the torque and the thrust produced by the tail rotor. When you close the throttle to initiate the hovering auto, you reduce the torque. This leaves too much tail rotor thrust, which causes the helicopter to rotate in the direction of the main rotor rotation. I’m sure you have noticed that you don’t apply full right pedal, otherwise you would begin to rotate to the right instead of the left.

    It’s all a balancing act. Also, note that the pedal application will be reversed if the main rotor rotates the opposite direction, such as Astar.

    +2 Votes Thumb up 3 Votes Thumb down 1 Votes

  2. wes eads on Apr 24, 2017

    That makes perfect sense, well said! Thanks Kris

    0 Votes Thumb up 0 Votes Thumb down 0 Votes

  3. R. Anderson on May 06, 2017

    Kris’ answer is well written and explains the aerodynamics clearly.

    I would like to add that in my experience it’s helpful to minimize the mechanical anticipation regarding which pedal will need to be pushed during torque changes. (hovering auto, liftoff, situations requiring significant power changes, etc.). For me, it’s most effective, since both feet are always on the pedals, to focus on keeping the nose of the helicopter straight. Whether you are pushing on the right pedal or releasing pressure on the left pedal, keeping the nose straight is often easier to accomplish than overthinking the aerodynamics. (for me anyway)

    Same thing with an engine failure on a multi-engine airplane. There are so many variables that, during stressful circumstances, if you mechanically move the rudder pedals in response to which engine you believe may be inoperative, you may wind up rolling the airplane upside down. (it has happened!) Flying the aircraft based on the visual cues, VMC (horizon or other outside reference point) or IMC (using the heading indicator, attitude indicator, etc.) allows your natural flying skills to overcome any potential shortcomings based on overthinking mechanical requirements based on your knowledge of aerodynamics. This is especially true during rapid changes in power during critical situations.

    Perhaps I’m a bit off topic, but your question made me reflect on a variety experiences I’ve had in flying myself or teaching others.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes

The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.