The torque roll

Discussion in 'Technical' started by Milosh, Oct 22, 2009.

  1. Milosh

    Milosh Well-Known Member

    Joined:
    Aug 10, 2009
    Messages:
    1,919
    Likes Received:
    96
    Trophy Points:
    48
    Can someone explain why an airplane torque roll is, please.
     
  2. Shortround6

    Shortround6 Well-Known Member

    Joined:
    Jun 29, 2009
    Messages:
    9,770
    Likes Received:
    801
    Trophy Points:
    113
    Occupation:
    retired Firefighter
    Location:
    Central Florida Highlands
    If, say the propeller rotates to the right, it is the tendency of the airplane to rotate (roll) to the left when the throttle is opened.
     
  3. Messy1

    Messy1 Well-Known Member

    Joined:
    Nov 21, 2007
    Messages:
    2,708
    Likes Received:
    29
    Trophy Points:
    48
    Occupation:
    Sales for Karl Performance
    Location:
    Ankeny, Iowa
    Home Page:
    #3 Messy1, Oct 22, 2009
    Last edited: Oct 22, 2009
    It's the forces of the engine and propeller being transferred to the body of the plane.
     
  4. vanir

    vanir Banned

    Joined:
    Jul 22, 2005
    Messages:
    705
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Melbourne
    Answers above correct. The torque of the motor is working on a body of mass, the crankshaft, the conrods, the prop, the body of the plane wants to rotate in the other direction because of Newton's law (equal and opposite reaction).

    With inline engines some of the torque is transmitted torsionally along a long crankshaft, so it spreads out over a greater area. This is why radial engines produce sharper torque rolls, because the torque from the motor is being transmitted onto a small cranksaft and is felt more suddenly and dramatically by the airframe.
     
  5. Shortround6

    Shortround6 Well-Known Member

    Joined:
    Jun 29, 2009
    Messages:
    9,770
    Likes Received:
    801
    Trophy Points:
    113
    Occupation:
    retired Firefighter
    Location:
    Central Florida Highlands
    Also radial engines are usually bigger, more displacement= more torque, more torque=more reaction
     
  6. Wiking

    Wiking New Member

    Joined:
    Jun 28, 2009
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    USA Norway
    The descriptions are good. Modern US aviation terminology calls it torque reaction, but 'Torque Roll' works well.

    Some examples to illustrate the concept:

    - An aircraft mechanic friend was witness to a F4U Corsair accident in which the pilot applied too much throttle too early in his take-off, still low (perhaps in ground effect) and the force of torque overcame the aerodynamic capabilities of the wings, rolled the plane inverted and it crashed on the runway.

    - In flight a pilot could take advantage of torque roll, since the plane would roll faster in one direction than the other. If the pilot knew an attacker's aircraft had an opposite-spin prop, he'd roll in the direction of best advantage. I have heard this being the case primarily in WW1 when even some engines rotated with the prop. (Rotary engine vs Radial).
     
  7. Guns'n'Props

    Guns'n'Props Member

    Joined:
    Sep 18, 2009
    Messages:
    52
    Likes Received:
    0
    Trophy Points:
    6
    Occupation:
    Bits, bytes and project deadlines
    Yep The Sopwith Camel was the classic case. It was easier and faster to turn 270 degrees than go directly left if I remember correctly. Still a great fighter for WW1.
     
Loading...

Share This Page